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Understanding and Diagnosing Rear Differential Noise

The rear differential plays a very large role in the working assembly of a car, truck or semi. We all know that a vehicle works via its engine’s piston motion which is powered by fuel combustion. But how exactly does the motion of the piston or crankshaft convert to the rotational motion of the wheels? Let’s take a look at the magic of the rear differential and the problems that arise from rear differential noise.

Rear differential noise is a usual indication of a lubrication or gear alignment problem.What is the Purpose of a Rear Differential?

The differential is the final end mechanism that enables the creation of torque in the crankshaft before it is distributed through the transmission, to the drive shaft, and then to the wheels. This part serves to transmit engine power to the wheels while also enabling them to have different rotation speeds. This very purpose is the reason behind the name ‘differential’—because it can distribute different kinds of speeds to wheels especially during a turn.

The pair of driving wheels in a vehicle does not rotate at the same speed during a turn. In situations like this, the wheel on the turning side (inside wheel) rotates slower than its counterpart (outside wheel). This is made possible with the help of the rear differential’s side gears and spiders. To put it simply, this mechanism is the one that decides the speed and the frequency of the turning of the axle and wheels in relation to the turning of the drive shaft. This is often referred to ring and pinion ratio. If for example you have a rear gear ratio of 3.73:1, this simply means that the drive shaft (which is connected directly to the pinion gear) is going to rotate 3.73 times to the wheels turning one, full rotation.

Misaligned gears are one of the most common causes of rear differential noise.

Rear Differential Noise

The rear differential is made up of many gears with teeth entwined with each other. The effectiveness of its function is dependent on how precise these gears are arranged and oriented relative to each other.   If, for example, lubrication runs low on the mechanism or the arrangement of the gears goes out of place, rear differential noise occurs. Gear whine, bearing noise and clunking are common rear differential noises that should be a concern to vehicle owners.

Worn spider and side gears of a differential carrier are common for rear differential noiseDiagnosing Rear Differential Noise

There are various situations which can create rear differential noise. For example, howling of gears is a sure sign of wearing. If you notice that the howling noise only occurs during deceleration, then it is a good indicator that the pinion-bearing preload has loosened.

Howling under acceleration at various speeds, however, indicates that the gears are already worn out or are out of alignment or depth with each other. If rear differential noise occurs while accelerating the car only at a certain speed, it is likely because the gears have become worn due to overloading and lubrication failure. If your gears are newly installed and still create a howling noise, double-check its preload  and make sure that the teeth are properly aligned.

Rumbling and whirring noises at speed over 20 mph, moreover, can be the result of worn carrier bearings. For vehicles with C-clip axles, the rear differential noise may change at different turns. Generally, worn out pinion bearings can create whirring noises at various speeds, be it may during deceleration and/or acceleration. If the pinion bearings are the problem, they create more of a whirring noise than a rumble because it turns several times faster than the carrier assembly. Regular clunking every few feet can also be an indicator of a broken pinion gear and/or chipped and damaged ring gear.

Overly worn out bearings tend to make a howling noise when they do not properly support the gears. Rumbling while turning, on the other hand, is a sign of bad wheel bearings. Clunking and banging noises on the corners can be due to lack of sufficient posi-traction lubrication, broken spider gears, or worn posi-traction or limited-slip clutches.  Broken spider gears, moreover, can also immobilize the differential and create a loud, crunching sound during final departure. If the rear differential noise is characterized by clunking every two or three feet, then there is a great chance that a broken ring gear is the problem with the section with the broken teeth banging or grinding as it tries to engage the pinion.

Having a chipped or missing high spot on a gear tooth sounds closely similar to a broken gear except that the rear differential noise only happens while accelerating or decelerating. This is because the problem is just present on one side of the offending tooth. This rear differential noise is described as a heavy clicking type of sound which occurs every eight feet or so. If the pinion is the one that has a high spot, the noise occurs every two or three feet and is much more pronounced because of its higher frequency.

Proper lubrication is a good way of preventing the possibility of rear differential noise from occurring.Fixing Rear Differential Noise

Rear differential noise, when ignored, can lead to major problems and permanent damage on the ring and pinion. Repair of the differential is usually recommended to be left in the hands of professionals because of the complexity of the system.

Instead, what you could do is to boost up the lubrication on the differential instead. Providing proper lubrication levels will also lessen heat and friction and make the movements of gears against each other much smoother and quieter. This is merely a preventive step, however, and a replacement of the entire mechanism is still recommended for those who have been delayed in fixing the problem.

In terms of lubricants, one very good example is Boost Performance Product’s CleanBoost® EMT™ Engine and Metal Treatment. This product is formulated with stabilizing anti-oxidants and special metal deactivators that ensures the smooth performance of the engine and gear applications. When applied, the gear oil in the differential carries this Engine and Metal Treatment to the asperities of the metals to form a covalent, galvanic bond on it. It provides 2 to 4 micron penetration into the surface, therefore lessening heat and friction and quieting rear differential noise where applicable.

For more information about this product, simply head here.

 Thanks for reading our article today, click here to receive a Free 1 oz. SHOT of CleanBoost® Maxx™

266 Responses to Understanding and Diagnosing Rear Differential Noise

  1. Tom Morton says:

    This article helped me out…. i had a howl / whine on deceleration. Took a video of the diff to make sure thats what it was…. Pinion preload was the probelm…. check out the video here for an example. https://youtu.be/CvmZ1xNTzAE

  2. Tech Guy says:

    Thanks Tom! That was one noisy differential… glad we could help.

  3. Amber Judd says:

    I have a salvage rear end just put it on a 2001 gmc safari and there is a grinding noise now but the differential oil is full.

  4. Tech Guy says:

    If the rear end is still functional, drain the gear oil and re-fill with a quality 80W90 GL-5 hypoid Gear Oil, then top off with CleanBoost EMT. The EMT (Engine & Metal Treatment will penetrate the metal and provide an improved mating surface combined with less friction and heat… which in turn should help to reduce the noise. However, if the rear end is trashed (meaning bearings are completely worn out, or the gears themselves are beyond normal wear and tear) then the only option is a rebuild and/or replacement of these components. You can purchase CleanBoost EMT here: http://boostperformanceproducts.com/28-oil-additives

  5. Lexly says:

    Everything that could go wrong wth Jeep has. I’ve owed it now for 13 years and have replaced mostly everything at some point. Its a 98 with low mileage so I won’t get rid of it… I had the front differential replaced already and I am POSITIVE the back is acting up…I hear the clunk on the right rear passenger side when i turn left and when i hit a bump every so often…So my question is can I drive for a few more weeks without my wheels falling off ? I can’t get it fixed till then.

    @TechGuy: Hi there… it’s hard to say if your rear differential will last until you get it fixed. Sounds like a mechanical problem with the limited slip unit or the spider/side gears. A qualified mechanic should be able to help you diagnose this and get you an accurate estimate for repairs. Best of luck!

  6. Blake says:

    I’m having a rumble or hopping feeling from my rear end only when I turn from a dead stop, as in a right or left from a stop sign but it don’t do it if I very slowly ease into the turn which isn’t possible in traffic. I drive a 99 f250 with 100,000 miles well taken care of, the style of f250 that has a 150 body but 250 chassis and drivetrain. Any advice or help would be greatly appreciated

  7. Tech Guy says:

    @Blake, Sorry to hear about your rear differential troubles. I would drain the gear fluid first and look to see if the old oil has any metal fragments or friction materials in it. This way, you can determine quickly if it’s in need of mechanical repairs. It may be that the rear limited slip (I’m assuming it has one) assembly is acting up and that is causing the ‘rumble’ or ‘hopping’ sensation that you can feel as one wheel is trying to limit itself in the radius of the turn from a dead stop. It’s a somewhat common occurrence when a limited slip has springs, clutches that begin to malfunction. Sometimes, it can be as simple as a fresh fluid change with a quality 80W90 GL-5 hypoid Gear Oil. Keep us posted & good luck!

  8. Charles says:

    I have a 2004 Lincoln Aviator, with 154,150 miles, and for several months I’ve been hearing a whining or howling sound, particularly upon coming to a stop or slowing down. I’ve assumed that it was my expensive Michelin tires, but today, the noise was present during acceleration as well. It sounds like metal rubbing together, or a clicking/grinding sound. I’m bad at describing sounds… Does this sounds like a bad rear differential? If so, does a bad rear differential cause acceleration/hesitation and harsh/delayed engagement problems? If not, does a bad rear differential cause any drivability problems?

  9. Tech Guy says:

    @Charles, the whining or howling during deceleration can be caused by excessive backlash from the ring and pinion setup… combined with a noise of metal rubbing or grinding, could be a pinion nut that has essentially ‘backed off’ from it’s factory setting. These items can cause drivability problems and increased likelihood of a breakdown with even more expensive repairs. It’s probably best to have the rear differential inspected by draining/removing the rear cover and looking for the signs of ring & pinion wear, excessive backlash and/or bearing and race wear. Here’s a great YouTube video on how to drain and fill your rear differential just to help you with a reference of inspection: https://www.youtube.com/watch?v=KmqMUJb-E4M
    Once you get yours opened up, you want to be checking for a damaged ring gear (teeth chipping, uneven wear, etc.) and other component (side gears & spiders or limited slip) damage. There are other videos as well that may help more with the inspection aspect once you get yours open to take a look. Best of luck and keep us posted!

  10. kenneth says:

    Thank u

  11. Dale says:

    I have a 10 bolt rear end on my 95 Chevrolet C1500 long bed truck (w/ no carrier bearing) that has a clunking noise when shifting from rev to drive. It also has a tendency to clunk after taking off from a dead stop and will sometimes give a bump from behind feel when stopping. Checked u joints and they seem to be tight! Am going to pull cover and check torque converter bolts to see if loose next. If they aren’t am kind of stumped… What degree of free travel should there be in the rear yoke when going back and forth from forward and reverse? It is strange as you can pop the center of the driveshaft and hear it clunk! Any suggestions would be greatly appreciated!!

  12. Tech Guy says:

    @Dale, There are a couple of things to consider here, both of which require an inspection of the rear differential. The first thing to check is to see that the pinion nut has not ‘backed off’ from its factory torque or setting. Excessive backlash is of suspect here. There are some YouTube videos on this topic and how to check for this condition. The second thing is that there may well be a ring & pinion problem, again could be caused by excessive backlash, low or contaminated lubricant or wear. This requires pulling the 10 bolt cover off and inspecting for abnormal wear that will be evidenced on the ring gear by uneven wear or possibly chipped teeth. Here’s a great YouTube video on how to drain and fill your rear differential just to help you with a reference of inspection: https://www.youtube.com/watch?v=KmqMUJb-E4M
    Keep us posted after you’ve had it checked out and good luck.

  13. Roy Barghout says:

    Hi tech Guy, hope you're well and thanks for the above article.
    I'm hearing a noise in the back of my 93 Nissan Patrol. The mechanic told me that it's from the tyres, because, if i shift the gear into neutral, the noise remains.
    I recently changed the Diff housing but the noise was sounding before that.

  14. Tech Guy says:

    Hi Roy,

    So if I’m understanding correctly… after you changed the differential housing out, the sound remained unchanged? If that’s the case, I would have to agree that the sound may not be coming from your differential, but rather another source, such as a wheel bearing (common issue) or maybe tires as your mechanic suggests. If you post up a video of the sound, (mount a video camera hanging from the rear of your Nissan where it can pickup the noise while in motion) maybe we can help a little further. If you do have the ability to do so, please record acceleration, deceleration, coasting and neutral. Take care and let us know.

  15. Hello I have a question I hope I can get some help with. I have a 2005 chevy duramax 4×4 2500 I was pulling a trailer with aprox 8000 lbs and it started making lots of noise underneith I stopped it and had it towed home i put it up on jacks and with in gear at idle the back tires makes a couple turns then stops theres a loud clank then they start turning again this happens every time, but also there is a loud noise coming from I think the transfer case its a loud howling noise, I am just stumped please help……

  16. Tech Guy says:

    Hey Steven,

    I would definitely remove the rear differential housing cover and do a good visual inspection of the ring and pinion, side gears and spider gears. Here’s a great YouTube video on how to drain and fill your rear differential just to help you with a reference of inspection: https://www.youtube.com/watch?v=KmqMUJb-E4M

    Thanks and good luck, feel free to keep us posted with what you find out.

  17. Anonymous says:

    Hey Tech Guy, I posted the ? At top of this page. I went for a oil change this am and they told me the “positive clips were broken on rear diff” & would cost me $671. for repair. I don’t hear any noises (whining, crunching or any other noise) at all. I had new rack & pinion installed 2/2014. They also said this am that there was a small leak in the r & p. My truck is a 2002 Dodge 1500 quad cab with only 63000 miles. Typical little old lady vehicle. Is this normal and should I do repair or can I put it off a while? I don’t have this money. Help!!!!

  18. Donna says:

    Hey Tech Guy, I posted the ? At top of this page. I went for a oil change this am and they told me the “positive clips were broken on rear diff” & would cost me $671. for repair. I don’t hear any noises (whining, crunching or any other noise) at all. I had new rack & pinion installed 2/2014. They also said this am that there was a small leak in the r & p. My truck is a 2002 Dodge 1500 quad cab with only 63000 miles. Typical little old lady vehicle. Is this normal and should I do repair or can I put it off a while? I don’t have this money. Help!!!!

  19. Tech Guy says:

    Hi there Donna!

    I’m assuming that when you say ‘rack & pinion’ installed, that you really mean ‘ring & pinion’. There are ‘positive clips’ on Traction-Loc differentials for Chrysler products. I tend to think that your truck may be this type of differential. I would find out how they determined that the posi clips were broken on your rear differential? Did they pull the rear differential cover and inspect it? Did they show you what exactly was broken by chance? Count the bolts on your rear differential… are there 12 bolts on the cover? Here’s a handy reference that shows the 4 clips on this type of Traction-Loc differential: http://www.riversidegear.com/on-sale-special-for-july-august-2015-925-dodge-traction-loc-rebuild-kit-fits-dodge-ram-dakota-durang.html

    Hope this helps. Good luck and keep us posted.

  20. Donna says:

    Thanks. No didn’t talk to anyone or see anything. Was at Chrysler dealership and you only see the person at the desk. I did have a Rack & Pinion installed in the front end of my truck. I don’t think that has anything to do with the differential I guess. Maybe I should get a second opinion. There is a Exxon station that has done work on my truck. I will run it over there tomorrow. I can see what is involved and get a better price. Thanks for the info. I will let you know what they find. I just can’t see that happening at 63000 miles. ????

  21. Daniel says:

    Hey tech guy.
    I’ve recently installed a 2″ suspension lift in my 2004 hilux and ever since it’s been making a howling/whining noise under acceleration. BUT! I only hear this noise between 90-100kph. Soo this leads me to think that the nut on the pinion is loose? Any help or advice would be great thanks mate

  22. Tech Guy says:

    Hi Daniel,

    If you used rear blocks to raise the suspension, were they ‘canted’, meaning were they manufactured with a little less lift on the front of the blocks to be installed towards the front of the differential? If yes, you may want to double check that you have them installed that way and not reversed which would put even more stress on the rear pinion. Even with blocks that do not have canting built in, 2 inches of rear lift does change the angle of the rear driveline to the pinion. If you did have a rear pinion nut that was not tight or set to factory spec, it is possible that you now have more stress on the pinion and have effectively changed its relation to the ring gear, hence the howling/whining noise under acceleration. Double check the pinion nut torque and block installation direction and keep us posted. Good luck!

  23. Michael says:

    99 Chevy 1500 4.8 4×4. Only use 2wheel drive. Vehicle clunks while switching park to reverse or drive. Driving vehicle rumbles a bit. Hard clanking when breaking. Slight clank sometimes when coasting. Some clank when letting off gas n getting back on gas. Prognosis?

  24. Tech Guy says:

    Hi Michael,

    You got a lot of clanking going on. The first and easiest place to start is to check the u-joints. Check the front and rear. Some drivelines use a carrier bearing with an additional u-joint in the area, so be sure to check them all for wear and play. If all the u-joints are greased and tight, then I would suspect the rear differential pinion nut has backed off from its original setting and torque. Good luck and keep us posted.

  25. Donna says:

    Hey Tech Guy,
    I finally talked to the mechanic about the 4 broken positive clips on my differential. He said they are just rolling around in there and might not cause a problem for a long while as long as I am not going on any long trips. Since it takes me a year to put enough miles on my truck to get a oil change I hope I don’t need to worry about it. Thanks.

  26. CutlassMan says:

    Hey tech guy I recently put in a 12 bolt Chevy rearend n put 4.10 gears noticed a slight leak from the pinion when drivin.. It then began howling n during acceleration would bog n not keep rpm could this be because it’s low fluid I’m a take it apart n hope to god there is no steal shavings. Once it began happening I stopped n towed it home..

  27. Gus says:

    Hi tech guy, I have a 03 Dakota that howls from the rear differential when cornering and also has a loud popping and grinding sound when taking off from a dead stop. The grinding and popping aren’t present all the time but does seem to be getting worse when it is present.

  28. Tech Guy says:

    Hi CutlassMan,

    Hard to say on this one… was this a rebuilt rearend or a salvage rearend? Sounds like it had some pre-existing conditions and ring & pinion backlash problems. Also, did you check the differential fluid level after you installed the reareand and before driving it? Keep us posted on what you find out after taking it apart. Best of luck!

  29. Tech Guy says:

    Hi Gus,

    A ‘cornering howl’ could be caused by a limited slip problem. Many of these trucks have a Traction-Loc differential and can have these types of issues. Unfortunately, the only way to find out, is to take it apart for inspection. You’ll want to be looking for the obvious things, i.e. missing positive clips, overheated components that will have discoloration, excessive ring and pinion wear, chipped components or bearing damage. Please keep us posted with what you find out. This helps others having a similar issue. Best of luck!

  30. tajinder singh says:

    Hi.
    I read some comments seems like its working out. I have honda crv 1996. And it has a countinous noise coming ftom back. First I thought it might be the hub axle. But I replaced it did not make a difference. What should I do. Its countinoud sound like I am in the plane :’)

  31. Tech Guy says:

    Hi there,

    I would be suspicious of the opposite rear axle hub bearing assembly. The sounds do sometimes carry and even though you may have thought it was coming from the passenger side, it could well be the drivers side rear. One final note is to swap the rear tires to the front and vice versa. I have seen some tires cause some pretty far-fetched sounds when they begin to ‘separate’ internally. Just a couple of thoughts… please keep us posted on what you find out and good luck!

  32. joji says:

    Hi tech guy!!!

    I own a 2008 dodge charger.Last week onwards I am hearing howling sound from rear when the car is accelerating from 60 to 80km/hr.Can you tell me what could be the problem???

  33. Tech Guy says:

    Hi joji,

    Have you checked the rear differential fluid level lately? I would recommend doing so just to be sure as a first step. This sounds strange, but a failing exhaust hanger can cause a pipe to drop enough to make contact with the rear axle housing and make a sound that can be mistaken for gear problems. From there, if the fluid level is okay you may be looking at some gear wear becoming evident. In this case, it is difficult to correct once it begins. Usually this type of repair requires a ring & pinion replacement. Could also mean a bearing in the rear end is starting to fail. These latter suggestions do require a visual inspection by removing the rear differential cover and carefully examining for uneven wear and/or bearing failure. Good luck and keep us posted.

  34. Al says:

    Hi Tech Guy thanks for great article and Q&A’s
    my rear drive 96 buick roadmaster developed a noise right after a reman transmission was installed and I tried to test drive it in different gears. The metal scraping against metal noise appears only in 1st gear and ONLY on deceleration immediately after I take my foot off the gas pedal and the noise disappears when speed is below 5-10 mph. Also driving at highway speeds with this new tranny produces gear noise you can hear the gears working somewhere as if there is no lubrication.
    The car was tested with its rear wheels up in the air and in all gears and the scraping sound was present only for a moment and it is coming from the rear differential each the gas pedal was released. the area below the u joint seal is a bit wet and the oil has some dark streaks in it and oil level seems to be ok. Is it possible that transmission only in 1st gear somehow jams or brakes the drive shaft. I never use 1st gear to drive anyway (only overdrive ) hope that if I never engage the 1st gear car could be driven without problems.

  35. Tech Guy says:

    Hello Al,

    If the noise developed directly after the reman transmission was installed, I would be looking at a couple of things here first. (1). Did you do the installation yourself and know that the transmission installed was an exact replacement for the stock? The reason I say this is because some the 96 and earlier transmissions of 4L60E’s are getting hard to find. So unless they rebuilt your core (old trans), they could have potentially used a newer model and the tail shaft housing length may be a little longer. Look and see if the tail shaft housing still has 4 bolts on it and not 6 as well as asking the shop where you bought your trans if it was indeed the same exactly in length overall. The slightest difference in trans length affects the angle on the drive line. A slight difference will be taken up in the slip yoke on the drive line and with no real noticeable visual difference. However, it does change the angle of the drive line and can cause a slightly different stress on the rear pinion shaft bearing and possibly the engagement to the ring gear IF the rear pinion nut has backed off at all or if the pinion bearings are getting worn to a point where this can occur.

    (2). If you own a Go-Pro camera or know a friend with one… I would find a way to securely mount it under the vehicle and pointed at the rear differential, with the Go-Pro back door changed to the Skeleton door (this allows maximum sound to the Go-Pro, however be sure to do this on a clean and dry road as to not damage the Go-Pro camera). With the Go-Pro mounted securely and as described, you can do a test drive to verify that this sound is indeed coming from the rear differential. One thing about drive lines, they are super carriers of sound. They can easily transmit sound from one end to the other and you just want to be really sure that this new sound is coming from where you believe it is. A careful review of the Go-Pro footage will reveal this for you and maybe even give you some additional insight. Good luck and I hope this helps you some. Please feel free to keep us posted.

  36. Al says:

    Hi Tech Guy
    Thank you for taking your time and replying so fast and so thoroughly
    one correction I meant yoke seal in differential not u joint
    According to the mechanic who used an electronic listening device/stethoscope the sound is coming from the differential
    The original transmission is gone and replacement is a reman from nationwide chain of auto parts stores that sells a few brands of remans which are shipped directly from remanufacturer. When I received the tranny with torque converter it had no tail part nor other attached parts so the tail is original as are other attachments like cooling line connectors dipstick etc. When I was ordering the reman I had to supply info about my car even the vin number (but that is probably mostly for warranty purposes). I didn’t measure the reman tranny’s length it looked about the same as the original less stickers from original . One more thing this is a third tranny after the original died the previous two from supposedly sound cars from junk yards not even from a buick were not good slipped and such. So the original tail has a new home for the 3rd time and noise in 1st gear appeared only on this reman latest one. I love this big car too bad they stopped making these so I try to keep it as long as possible but if it starts to fall apart then i guess it is time to move on.

  37. Tech Guy says:

    Thanks Al, One final thought would be to check for excessive backlash on the rear pinion gear. It could be that the pinion nut has backed off just a bit (this will also facilitate a yoke seal leak) allowing the pinion to essentially ‘move’ under deceleration and cause this type of noise. Worth checking out for sure. Best of luck… those big cars can be great keepers. 🙂

  38. charles says:

    I just bought a 1993 Chevrolet 3500 dually with 200,000 miles. it has a whining noise during acceleration but not during decleration. what can be added or done to help.

  39. Tech Guy says:

    Hi Charles,

    Sounds like a rear pinion bearing as this is a common culprit of gear noise/whine during acceleration. The bearing wear is allowing the pinion to move just enough that it is trying to cut a new pattern on to the ring gear. Short of complete disassembly, there isn’t really a magic additive to permanently reduce the whining noise. Additives may reduce it for some time, but it will return most likely. The best bet is to inspect it and most likely repair and replace the worn and damaged components/bearings. Best of luck and keep us posted!

  40. Ralph Waller says:

    I just had 3.73’s installed on my ’05 Mustang GT. I don’t notice any gear noise until I get into 5th gear and cruising on the highway. The sound is very reminiscent of an engine at high RPMs, probably the best way to describe it. The sound is loud enough to be annoying for sure. I’ve had the gears installed for just 2 days now (less than 100 miles on them). Thank you for your help!

  41. Tech Guy says:

    Hello Ralph,

    The first few hundred miles are critical to the break-in of the gear pattern that will become permanent for this fresh install. If the pinion depth is set either too shallow or too deep, you could get this type of noise, since the pinion gear is riding on either the heel or toe of the ring gear rather than in the ‘sweet spot’ for smooth, noise free engagement. Maybe try letting your installer know what you’re experiencing along with a test drive with their technician to verify the noise and recommendation from here. Best of luck, and please keep us posted.

  42. Hello Mr. Tech Guy,
    I have a big issue with my Automatic 2007 Ford F-150 4.2 Regular cab with an 8' bed.
    When accelerating I feel a light bump. The transmission runs smooth. After I drive all day around the city of Miami.
    With rush traffic and light stops.. The truck at about 20 miles per hour when shiffting into 2nd gear gives me a big bump. It feels like I get hit from the back. When stuck in traffic I run the car from (2) second gear and the problem goes away. If I put heavy loads on the trunk the problem is less notisable and sometimes Is not there even in heavy traffic. I have taken the truck to a local AAMCO Transmission expesialist and the diagnostic is that the transmission is fine that the problem is the in the differential. Now they are ordering the parts to replace the cassing, the pin and 2 bearings that go along with the cassing. Labor $450… Parts about $100..
    From your experience do you believe this is the problem or is it the transmission? Also when going in reverse I hear a loud humming noise comming from underneath. Other thing is a little rathel shake of when going 60 to 65 mph. All could be a simptom for differential but I'm affraid they are not going to fix the bump at second gear when warm. Please advise.
    Thank you for the article is excelent.

  43. Tech Guy says:

    Hello Bernardo,

    Thank you! Most likely the noise is coming from the rear end, when the transmission shifts into second gear, the “slack” in the rear end causes the “big bump” type of feeling as you describe.
    I would suggest you look at the front u-joint and see if it is a constant velocity style or a single u-joint on a slip yolk, it may be a non-greasable type, which is worn out and causing the vibration while shifting. Good luck and keep us posted.

  44. Hakim says:

    Hi Mr Tech guy, I recently changed differential oil at a shop as I noticed sounds from rear while I decellerate. The car is 2006 S500 4matic. Today I noticed oil leak at the left side of diff. The mechanic put the car on lift and heard grinding noise using stethescope. He says I need to replace the differential. Need your advice. Would a cheap fix possible I mean repair ? Thanks..

  45. Tech Guy says:

    Hello Hakim,

    Sounds somewhat serious. The grinding sound could either be bearing failure or differential side gears possibly. You should have a reliable technician do an inspection for you to see to what extent any damage has occurred. Best of luck and keep us posted.

  46. Cory says:

    Hi tech guy!
    I have aa 2007 f250 super duty 6.0 powerstroke 2wd that is grinding / clinking around turns and in reverse while turning. Also I noticed that after driving at highway speed for 30 minutes or more, I get a burning smell and the rear end pops until it cools a bit. Please help!

  47. Tech Guy says:

    Hello Cory,

    Sounds like a limited slip problem at first glance. Have you checked your fluid level lately? If yes, and its okay… it’s probably time to drop the rear inspection cover and have a look at the limited slip assembly and related components for wear and/or abnormal wear. Good luck and keep us posted on what you find out.

  48. Calvin says:

    2011 F150. There is a deep rumble when turning from a dead stop. This was an issue after I had my rear differential serviced. Any suggestions? Would changing oil cause a deep rumble.

  49. Tech Guy says:

    Hi Calvin,

    Normally a simple fluid change wouldn’t cause what you’re describing, unless perhaps the wrong fluid was installed in a limited slip rear differential. In this case, a high quality Hypoid GL-5 gear lubricant should be used. Otherwise the clutch packs could potentially make noise turning from a dead stop as the limited slip tries to engage and release. There is one caveat, if you’re accelerating quickly during the turn from a dead stop, then you would have the clutch packs trying to engage anyway. You may want to have the shop double check what fluid was used during your trucks service. Best of luck and keep us posted.

  50. Carl henry says:

    How are you doing.I have a 93 g.mc envoy 4by4 that I’ve never used b.t.w.my r.PMS would be really high like as if I was having transmission problems. And out of nowhere when going from reverse into drive I would like a jolt or bang like someone hit me from behind I know absolutely nothing about cars and figured it would go away. I know my bad! Now my truck starts sounds good in drive but when I put it in reverse there’s a loud grinding crunching noise and it won’t even move I had a mobile mechanic come look at it and was told it was the rear end diff w.t.h I just bought it 2 months ago.my ? Sir or ?s are being im green when it comes to cars does this sound like what it is and I found a person parting out a envoy andthey are willing to sell me the rear end diff for super cheap but there’s is not a 4by 4 can I use it P.S wish I knew a fraction of what you know about cars I’d be rolling right now

  51. Tech Guy says:

    Hi Carl,

    Sounds like you should get a second opinion/diagnosis just to be sure. If you do change your rear end out and use one out of any other Envoy, you would first have to check to see that it has the same gear ratio as yours. The reason is because your 4X4 has to have the same gears in the rear differential as it does in the front differential for any 4X4 operation. It’s interesting that it does okay in drive, but not in reverse. It’s true that it could be the rear differential, however I would advise having another technician take a look just to eliminate the possibility of the transmission and any u-joint, or even a loose rear pinion nut. Good luck and keep us posted.

  52. Frank Younce says:

    I've got a 1959 F100 that clunks only when I trun right. Its a constant clunk. Id say about equal to tire rotation. Whats tht all about ?

  53. Frank Younce says:

    and if I push in the clutch & coast through the turn it's not there. Also, if I drive in 4hi w/out the rear drive shaft, what are the ramifications ?

  54. Maurice says:

    2006 Cadillac CTS clunks during take off . After a half mile. It sounds like a heavy rumble…. then smooth out. It recurs often I’m afraid it’s going to break. Changed fluid, but it sounds like an internal problem still. Any ideas ? Thanks

  55. Tech Guy says:

    Hi Frank,

    My first thought is that most of the older pickups had open differentials, so I don’t believe your problem lies in a limited slip differential that is acting up unless someone installed one along the way (which is entirely possible in such an older truck). Rather, it sounds like you may have a side gear or even pinion gear(s) that may have a chipped tooth or even missing tooth or even missing teeth. Time for an inspection by removing the rear cover and taking a good look. Here is a link by Chris Fix, that will help you with that: https://www.youtube.com/watch?v=KmqMUJb-E4M Good luck and keep us posted.

  56. Tech Guy says:

    Hi again Frank,

    You could remove the rear drive shaft and engage only the front, however I don’t recommend this for daily driving, especially at highway speeds. The reason you’re not hearing the clunk when you coast through a turn is that there is very little pressure on the side and pinion gears in this situation. Once again, best to pull the rear differential cover and take a look.

  57. Tech Guy says:

    Hello Maurice,

    The rear differential in some of the CTS’s were prone to some problems. First off, I would check to be sure you don’t have a worn out rear differential bushing. This allows the rear differntial to move significantly during acceleration and deceleration. This movement causes a clunking sound against the frame bracket and this sound can carry into a rumble. If this is not the case and you don’t have any leaks, I would have the differential inspected by a qualified technician familiar with Getrag (this is the manufacturer) differentials to see what your problem is and any available options. Best of luck and keep us posted.

  58. Ryan says:

    I have a 2001 bmw 325i. When making left turns I get a loud rotational clunking or popping noise, which sounds like it’s coming from my rear right wheel. The more weight or passengers I have in the car, the louder it gets. Fixes I’ve tried.

    -wheel bearings done 20k ago.
    -axles done about 10k ago.
    -changed fluid 6 months ago. (That seemed to quiet things down for a couple of days)

    The noise is progressively getting worse. And it doesn’t seem to happen at all when turning right.

  59. Val says:

    Hi, I have a 2013 Cadillac CTS. It began stalling while driving on the highway and then began smoking a lot. I pulled over and the smoking stopped but black fluid was pouring out of the rear end. Cadillac dealer towed it in and said it is the rear differential. What would have caused this to happen?

  60. Tech Guy says:

    Hello Ryan,

    Since the right rear wheel in a left turn is moving much faster than the inside left rear wheel… I would venture to say that the limited slip is acting up and/or you have a damaged side/pinion gear in the rear differential. Probably best to have it inspected by a qualified technician or if you’re inclined to inspect it yourself, be sure to follow some directions from a repair manual on proper inspection method, fluid to use and the correct gasket or high temp RTV gasket maker/sealer. Good luck, feel free to keep us posted.

  61. Tech Guy says:

    Hello Val,

    Cadillac has had some real issues with their rear differentials on the CTS models for a number of years. It’s still an issue in my opinion. Some of the older models have had recalls along with the DOT getting involved on total rear differential (catastrophic) failures. If you have been having your CTS regularly serviced… that should have included a routine fluid level check on the rear diff. If this is the case (and they actually checked off that it was ok), then you may be able to take up a complaint with your local attorney general or the DOT. Apparently, you’re not alone in this, however most complaints about the CTS rear differentials are more about whining, noises and vibration occurrences rather than total failures. Once again, if the fluid level was good and the recommended fluid changes have been completed (depending on your miles) you may have some recourse in getting some of the cost to repair covered. Good luck and please keep us posted.

  62. alex says:

    I have a 2001 ford f150 5.4L triton. It has a weird whining or humming kind of noise when I accelerate or decelerate. Any suggestions?

  63. Matt says:

    I have a 2004 chevy silverado 1500 5.3 4×4 a few years back my spider gears exploded and i replaced the gears with a posi set up from yukon gear and axle now just recently i have had a groaning type noise from the rear end while turning and not to sure how to go about fixing it any thoughts on if any new fluid would help? I was leaning towards a noisy u-joint but they all seem fine, any help would be much appreciated!

  64. alex says:

    I have a 97 dodge dakota its a 5 speed. when I get up to 45 mph and I barley give it gas its macking a rumbling noise and when I let of the gas it makes th nois than stops than when I give it gas its makes the nois than stops can you help me

  65. Tech Guy says:

    Hello Alex,

    Without more detail, I would check to see that that the rear pinion nut has not backed off from its factory torque setting first. Followed by a fluid check, drain and new fluid installed. Sometimes, the rear pinion nut does loosen and can cause the pinion depth to change just enough to start ‘cutting’ a new pattern on the ring gear and that could be what you’re hearing as a whine. Good luck and keep us posted.

  66. Tech Guy says:

    Hello Matt,

    Depending on the posi setup that you installed, I would first do a fluid check and/or inspection by removing the rear cover to see if there are any obvious problems with abnormal wear on the spiders and side gears. Also, check your springs, plates, clips, etc. If everything looks okay, then re-install their recommended fluid and see if that helps. If this is a mechanical posi (no clutches), then you could try some CleanBoost® EMT™ in the rear diff as well. When EMT is applied, the gear oil in the differential carries this Engine and Metal Treatment to the asperities of the metals to form a covalent, galvanic bond on it. Good luck and keep us posted.

  67. Tech Guy says:

    Hello Alex,

    If your Dakota makes this noise at 45 MPH in 3rd or 4th gear… in other words, it doesn’t seem to make a difference what gear you’re in (you’re trying to eliminate if the transmission is making the noise) then I would first check your u-joints to see that they’re not worn out and vibrating/rumbling. Be sure to really check them for any looseness or failure, they can be deceiving sometimes. If your u-joints are okay, then I would pull the rear differential cover for an inspection of the gears and limited slip components. Good luck! Keep us posted up as to what you find out.

  68. Daphne says:

    Hi,
    I have a 2007 Ford F-150 4.6, 4×4. I have had the rear differential clutch pack replaced, pinion & seals along with anything else related because it was making a thumping/clunking noise when slowing down as well when turning. It has only been a couple weeks since all this was done and it has started making the same noise again. I returned my truck to the garage where I had the work done and they put more friction modifier in it. A couple days later it started making the same noise again. Any ideas as to why or what else could be wrong? Any help would be greatly appreciated!

  69. Desi Dinero says:

    Howdy, very informational info posted here. I am especially interested in the clicking sound.
    I have a 1980 T/A, 4.9l, auto, original gears, which I believe are 2.73. Disk front, drums rear
    During turns either right or left, I hear or even feel a grinding sound, I say feel cause it is quite a heavy grind. At first I thought it might be the front disks but one day I took my brother with me and he said he could clearly hear the sound coming from the rear. Gets a lot worse and louder after 15 or so miles. Sound is not there on straight drives or straight stops or slow downs, only on turns.
    Also, the clicking sound,,here it goes. After a 15 or so mile drive and coming to a slow stop, there is a loud clicking/popping sound. Remember the old cement roads that have a divider every 10 or so yards that causes that distinctive sound when driving over them? Well that is almost what is sounds like.
    What I have done:
    1) replaced front disk brake, rotors and calipers, brake fluid lines
    2) replaced power steering pump
    3) replaced front springs springs
    4) replaced from end steering suspensions parts with Moogs
    5) replaced all shocks with OEM
    6) replaced trans mount
    7) replaced rear brake shoes
    8) drain trans fluid, filter slso
    9) replaced trans modulator
    10) replaced front and rear drive bar u-joints
    11) replaced diff oil, added 1 4oz. special GM additive. noticed no metal shavings but oil was light brown color and watery.
    12) replaced diff bearings
    13)replaced body mounts
    14)replaced all front/rear bushings with rubber bushings
    15)replaced front upper/lower ball joints

    And after this, the grinding and clicking sound is still there. If there was pinion or other metal parts bad or worn I should have noticed metal shavings of some sort right?
    Else will have to go back in and check for backed out nuts or other loose parts.
    Any input would be greatly appreciated. Most Respectfully?

    p.s., is there an exhaust expert on this website?

  70. Galen says:

    Good afternoon,
    I’m having problems with my wife’s 2006 gmc envoy xl v6. Not 4 wheel drive, doesn’t make sounds when in park or nuetral. Little sound when in reverse but mainly in drive on take off. Makes a whining sound and more present when car is first started and in cold temp but usually subsides when in 3rd gear. Any help would be greatly appreciated..

  71. Tech Guy says:

    Hello Daphne,

    I would have them check the clutch packs one more time. Sounds like they could be set too tight is my initial thought. Also, while they have the inspection cover off, have them double check the side gears and pinion gears for any signs of abnormal where. It sounds as though the clutches may be trying to engage/disengage and that may be making this sound as you describe. Thanks and keep us posted.

  72. Tech Guy says:

    Hello Desi,

    Have you had the rear wheel bearings checked or replaced? I know you had the rear diff bearings replaced, but you may want to have the wheel bearings checked out. Sometimes their noises really travel and do make a grinding noise sensation along with an associated vibration. If those checkout, then I would have the rear limited slip differential inspected for signs of wear along with the side and pinion gears. Just some initial thoughts. Please keep us posted as to what you find out and good luck.

  73. Tech Guy says:

    Hello Galen,

    Have you had the rear u-joints inspected or replaced? U-joints can make some strange noises at times as you describe. Also, I would have the rear differential fluid level inspected and/or changed. As a last point of inspect, make sure the rear pinion nut has not backed off from it’s factory position. When these do back off, it changes the depth of the pinion gear on the ring gear, which in turn can make a whining sound as you describe. Check these things out and keep us posted. Good luck.

  74. Fj cruiser says:

    Hi tech guy,

    I own a 2008 fj cruiser with an odo of 95k. The prob I suspect is the rear diff. I changed diff oil recently although yet the issue persists.
    My prob is, when the vehicle reaches 80km and above I hear a winning noise and when I decelerate the noise goes off. And also when I come to a full stop I hear a thud sound from the rear end. However, when I shift the gear to n while travelling and full stop, the thud noise does not appear. Further, when changing geas from n to d, I notice the thud noise sometimes. What may be the prob. Appreciate your assistance in this regard as this was the only article that explains something closer to the prob I have. Cheers

  75. Tech Guy says:

    Hello Fj cruiser,

    Sounds like you may have either a rear pinion nut that has backed off and therefore changed your pinion depth on the ring gear, or a possible ring and pinion failure. First, check to see that the rear pinion nut has not loosened from it’s factory setting. With the rear drive shaft disconnected, you should be able to feel for excessive back lash or play in the pinion shaft of the differential and inspect closely to see if this nut has indeed backed off. If there is no visible sign of this, then it’s best to remove the rear differential cover for a closer inspection of the gears and bearings. Best of luck and keep us posted.

  76. Max Janisch says:

    I just did a full re-build on my 2000 Cobra R w/ 8.8" IRS. I did 4:10 gears as well. The gears howl only when in neutral and rolling forward. It is quiet when going backwards. No sound as soon as you apply any throttle (load) on the car.

  77. Frank says:

    Have RearEnd Noise – 1998 Ford F250LD Limited Slip 3.73. TO be clear an F250LD is an F150 with special payload package. In recent years this could be had with the “7700 Payload” package. 205Light Duty came with thicker frame, 7lug wheels (ala the diesel world influence), 4whl disk brakes (in 1998 regular f150’s came with rear drums).

    Have Whirling noise at pretty much all speeds regardless of turns, as best you can hear with all the road and tire noise. When up on a rack, need to only turn the wheels and can hear constant whirring, like metal pates or gears rubbing, not really a grinding or banging or bumps, just noise. Sort of a swirling whir like the phase shiffter on your guitar effects.

    Ya, have a qualified tech listen…. replace bad parts. Seems like this would be all the parts 🙁

  78. Tech Guy says:

    Hello Max,

    If this howl is not all that noisy, I would say that you’re okay. Sometimes with higher gear ratios, you will have some ‘feedback’ on a no load condition. If however, this howl is particularly noisy, then your pinion preload may be off of the correct setting or depth. You may want to try CleanBoost® EMT™ which has a way of bonding with the metal to reduce friction and heat if your settings are correct. Just be sure to check with your limited slip manufacturer about what additives are okay for your setup. Good luck and keep us posted.

  79. Tech Guy says:

    Hello Frank,

    I would do a good visual inspect first with the rear differential cover removed and slowly rotate the wheels to see what is going on. Suspect that you may have differential side bearings going out as well. Check the side and pinion gears for excessive heat and/or wear. It may be time for a rebuild. You most likely have a lot of miles down on this good ol’ truck. Good luck and keep us posted.

  80. Derek says:

    I have a 72 Chevelle with a 12 bolt rear end with 390 gears Eaton posi differential and Richmond gears, new bearings, new axles. Ever since it was rebuilt with the new parts it has always been noisy, whining at 30 mph or more and especially a sudden harsh whine or rumble when passing through that neutral spot between acceleration and deceleration. I’m wondering if aftermarket gears are just naturally noisier than stock and i just have to get used to it? It sounds scary at higher speeds above 80 mph especially when coasting in that neutral throttle position I described before. I’ve brought the axle back to the guy who rebuilt it. He threw it back on the dial indicator after a year of use and he says everything is fine. Is this just a characteristic of aftermarket parts, lower gear ratio, or do I have a rear end that’s out of adjustment or something else? Thanks

  81. Dirk says:

    Please help. I have a 2006 Dodge Magnum 3.5l RWD and I have been getting a thump in the rear end at times when i let off the gas then accelerate or when I am just accelerating. I had the fluid in the differential changed and that did not resolve it. I brought it to a chrysler dealership and they said there is nothing wrong. The tumb at times is forceful enough for a passenger to believe we got hit in the back by something. Any help anyone could provide would be greatly appreciated.

  82. FORD LSD says:

    Hey Thanks for this

    My diff clunks when pulling up in my drive way just as i stop
    Does the same when reversing just about to stop
    Just hear a big clunk noise

    Using RP Oil 75w140 weight
    Borg Warner Diff, 4 pinion LSD

  83. oscar says:

    Hi tech guy, i have a 2000 mustang gt, and wen i let go of the gas it makes a whining noise i change the Outter bering and race in the pinion but the noise still continue wat the problen might be. Thanks!!

  84. Tech Guy says:

    Hello Derek,

    Did you install everything new at the same time? Or did you install the new bearings and axles afterwards? The reason I ask is it could be that the wear patterns for the ring and pinion were affected during the new bearings install. Otherwise, some aftermarket gears do make additional noise generally from 4.10:1 ratios and lower. Double check your pinion nut for correct torque and adjustment. Also, the next time you have the rear differential cover removed, inspect the wear patterns on the ring gear to see that that the pinion gear is not riding too high (on the heel) of the ring gear or for any signs of excessive ‘shine’ on the pinion where it might be riding too deep on the ring gear. If all else is well, you might want to try some CleanBoost® EMT™ (Engine & Metal Treatment) as it is one of the only products I know of that forms an actual covalent, galvanic bond to the metal allowing a 2 to 4 micron penetration into the metal. Sometimes this can quiet things down because it reduces any undue friction and heat. Good luck and keep us posted.

  85. Tech Guy says:

    Hello Dirk,

    As odd as this sounds, I would double check for any worn rear suspension components. Chrysler vehicles have been notorious for things of this nature. Specifically, check the rear control arm bushings and the subframe bushing and/or ball joint, rear upper shock mounts, etc. These noises transmit and often sound like a rear differential and can fool even the best technician. Just be sure and take some additional time inspecting these components for signs of wear or damage. You may need to have the rear of the car supported in such a fashion as to have the weight off of the rear suspension and using a pry bar, carefully move things around listening and watching for any undue movement or noise. Best of luck and feel free to keep us posted.

  86. Tech Guy says:

    Hello Ford LSD,

    Have you inspected the rear driveline u-joints? Also, inspect the rear pinion nut for signs of it backing off from its specified torque setting. Finally, if those checkout, then you may want to remove the rear differential cover and inspect the gears, bearings and your 4 pinion LSD for signs of wear or damage. These are all things that warrant checking out as you diagnose this type of ‘clunk’. If you have access to a GoPro or similar video camera, I would suggest securely mounting it under your vehicle and using it in your driveway with the microphone having full access as well. You just may pick something out of the video that is clunking to give you direction. Best of luck!

  87. Tech Guy says:

    Hi there Oscar,

    I would also inspect the rear inner pinion bearing and race. This could be allowing the preload to change and cause undue whining. Also, while you’re at it, inspect/replace the differential side bearings and even the wheel bearings. These 8.8 axles are pretty beefy, but they do wear components depending on how hard they have been used and taken care of in the past. Keep us posted and good luck.

  88. Jessiah Jones says:

    Hello I’m Jesse and i own a 88 jeep cherokee pioneer and I’m hearing a loud clank as I am slowing down coming of the interstate only at about 65 mph though, so I guess I was if my rear differential could be the problem. It only happens on deceleration and only at about 65 mph. I would really enjoy your input I’m only 17 and I don’t have the money to take it to a shop to get it worked on so I am trying to do these things myself with the help of a couple other buddies. We had just replaced one of my friends rear axle because his gears locked up. so know what it should look like inside I just want to know thats what it is before I take it all apart. I would like if someone could Email me their input on this at jonesjes@meadeschools.org , Thank you.

  89. Derek says:

    Thanks for your info. Ring, pinion, Eaton posi and related bearings were installed all at the same time. New axles and axle bearings were done at a later date and actually helped smooth out the overall ride of the car but the pinion/gear noise stayed unchanged. I believe you hit the nail on the head though, sounds like the pinion gear is riding too high on the heel. Is it true that this setup is much stronger but noisier? This would make sense since every time I’ve ever gone to this guy’s shop, he’s setting up gears in a 3000 horsepower drag car! I get the impression that he likes to set up all his gears for strength and some seriously hard launches and he probably assumes that everyone wants the same! This would also explain why he says everything looks perfectly fine after a year of use! I will check the wear pattern next to varify. Thanks again!

  90. I have a whine at 40-55 mph in a Jeep GC 2008. It is also audible at lower speeds and higher, but it is significant in the 2/3rd gears. the rear differential and axle assembly as well as the pinion bearings have all been replaced. Twice. The dealer swears that the parts are new and is now insisting on doing the same thing for the third time. I think it's an exercise in futility. any other ideas?

  91. Paul says:

    Hey tech guy,

    I have a 2004 Tahoe with the G80 rear end which is an Eaton locker. A few months ago I had a shop replace my u joints and after I developed a loud and very noticeable vibration while approach 70 mph and up until 75mph which it seems to go away. I had the drive shaft balanced, the u joints were greased and I replaced the rear dif gasket and filled with 75w90 full synthetic Mobil 1 gear lube. Do you have any idea what may be causing my vibration? The closest thing I can compare it too is a rapid rubbing type of vibration. Also, I get a clunk in the rear end when shifting from R to D or from park, sometimes when the Trans shifts from first to second. At around 55 mph – 60 mph when speeding up I get a slight howl that goes Away. And occasionally when decelerating or maintaining speed I get a sway/rocking in the rear end. Thank you sir I hope you can point me in the right direction.

  92. Tim says:

    Hello Tech Guy,

    I have a 2011 Dodge Ram 1500 2wd when I remove the rear tires and brakes (calipers and rotors) and I spin the axle by hand on either side I hear a kind of clicking or chattering sound that sounds like it is coming from the differential, this is only when the wheels are turned by hand and one wheel is spinning in the opposite direction, I initially heard it when I was slowing down almost to a stop and thought it may have been the brakes so I changed them before realizing the sound was coming from the differential. I took it to the dealership because it is still under warranty, 88,000 miles on it and at first they said they don’t hear the noise until I went up and spun the tires myself and then I was told it was the outer axle bearings, they said they changed them but on my way home I noticed it again. I took the tires and brakes off again and the noise is still there, the only signs of them working on anything is the new RTV sealant on the diff cover but it doesn’t look like anything was touched on the outer parts of the axles. I don’t hear the sound when one wheel is held tight while the other is spun or if I spin it by the driveshaft by hand, the exhaust is too loud to hear anything if I put it in drive to spin the axle with the truck running. I regularly tow 6000-7000 Lbs and I have a long trip coming up. Is this a normal sound from the posi or locking differential or is it something I need to worry about?

    Any help would be greatly appreciated and thanks in advance!

  93. Tim says:

    Correction to my previous post, after looking at it further the noise is present when the axle is turned by hand when it has both wheels off the ground as well as if I set one wheel down on the ground to hold it and spin the other wheel the noise is still there. So it doesn’t matter if one wheel is spinning or both the noise is present. Thanks again.

  94. Tech Guy says:

    Hello Barbara,

    My first followup question to the ‘the rear differential and axle assembly’… having been replaced is, did they actually replace the ring and pinion? A typical whine of this nature is usually caused by a small change in how the pinion gear ‘rides’ in the ring gear. Pinion depth and differential side to side adjustments are a tricky business when replaced or adjusted on existing gear sets. Quite commonly it is hard to get these settings back onto a well worn set of gears without causing a whine of some sort, simply because of the complexity of matching these new settings exactly to the previous ones so that ring & pinion are riding together just as they were before these components were replaced. If however, a new ring and pinion was installed at the same time, and providing they were setup correctly, these new gears now meet each other for the first time and begin their wear pattern journey from a fresh perspective and once established, it cannot be changed without creating some kind of gear whine. I hope this helps. Have this verified and keep us posted. Good luck!

  95. Tech Guy says:

    Hello Paul,

    So when you went in originally to get your u-joints replaced, what was the reason for replacement at that time? Was there a vibration before this at all? From your question, I understand that after this procedure, you then had the drive shaft balanced, the u-joints greased, and the rear diff filled with new fluid… did anything change at all vibration wise from these additional repairs? If not, I would be looking else where for your vibration and I would begin with wheel bearings. They can fool you as their vibration can really carry. After that inspection/replacement and not finding a resolution, I would be taking a closer look at both the inner and outer pinion bearings and races as well as the differential bearing sets. Your described ‘clunks’ are quite common on older gears as the backlash increases over miles and time. They are usually not too much of a concern unless they get excessive followed by other symptoms. Good luck and keep us posted.

  96. Tech Guy says:

    Hello Tim,

    A common sound such as this is the rear limited slip differential clutches, clips and/or preload spring. As they wear, they can become noisy or at least make some amount of clicking due to their wear characteristics. In order to replace the rear wheel bearings, the dealership had to remove the rear diff cover and remove the axle retainer c-clips (not to be confused with the aforementioned limited slip clips), so that’s about the only thing you will see evidence of. Maybe you could have these components visually inspected (which I’m assuming that the dealership took a look at when they had the rear diff cover removed) for signs of wear or noise with the cover removed. Hope this helps and keep us posted.

  97. Paul says:

    Hey Tech, I was thinking the axel bearings on the outter edge of the axel shafts in the rear. Previous to servicing the u joints I noticed a vibration when accelerating and at times maintaining speed. It was more of a shake at random times and I replaced them knowing that they were factory original. The current vibration is very odd it is felt feel able in the body of the truck and I can also hear it.

  98. john says:

    Hello tech guy

    I have a 05 f150 fx4. It has a bad vibration, seems like from the back end, every few feet between 50-60 mph. Had the tires changed and balanced. Doesn’t get worse when turning or going over bumps. Also when I let off the gas it seems to whine for a second or two when I’m between those speeds. Or when I have the cruise on and I’m going down a hill it has a weird vibration. The vibration is pretty violent and shakes everything.

  99. Caleb Salo says:

    Hello tech guy

    I have a 05 f150 fx4. It has a bad vibration, seems like from the back end, every few feet between 50-60 mph. Had the tires changed and balanced. Doesn't get worse when turning or going over bumps. Also when I let off the gas it seems to whine for a second or two when I'm between those speeds. Or when I have the cruise on and I'm going down a hill it has a weird vibration. The vibration is pretty violent and shakes everything.

  100. Jim says:

    Hi,
    I have a 1996 S10 pickup, very well maintained, now with 135,000 miles. No posi and does not haul heavy loads, just paint and ladder.

    I recently have developed a clicking or ticking noise when backing up and now in forward gear. The noise is constant and may subside only slightly in right turn but not by much. I inspected the rear brakes myself and found the trailing shoe had a crack so had my normal repair garage perform a brake job (shoes, kit and new drums which it needed). The ticking sound did not go away and is constant. It becomes less noticeable at higher speeds, but detectable at 40mph and below. It is NOT a outrageously loud sound but still can be heard with radio out.

    All the truck’s fluids were changed at 90,000 miles when I purchased the truck and I drive about 6,000 miles year or less (I am semi-retired). I am not up to replacing the differential and would like to get a few more years out of it, so I have considered adding a heavier Gear lube 90/140 with ingredients aimed at reducing friction/noise. Locally I have Lucas Gear lube 80/90 and 90/140. I thought about just pumping out a quart and replace with the heavier 90/140 or I could pull the cover, drain all and replace with the heavier Lucas Product.

    Questions:
    – Any thoughts on using a heavier lube, non posi, such as the 140 gear lube or is this too heavy?
    – Second Question, what normally causes the clicking noise in a non-posi differential?

  101. Tech Guy says:

    Hello John,

    I would first closely inspect the rear u-joints. Secondly, inspect the rear wheel bearings. Wheel bearings have a way of transmitting vibration and sound such as you describe. Thanks and keep us posted.

  102. Tech Guy says:

    Hello John,

    I would first closely inspect the rear u-joints. Secondly, inspect the rear wheel bearings. Wheel bearings have a way of transmitting vibration and sound such as you describe. Thanks and keep us posted.

  103. Tech Guy says:

    Hello Jim,

    Have you closely inspected your rear driveline u-joints? Normally, there is nothing that can cause a clicking noise in a rear non limited-slip or non posi rear differential. However, rear u-joints can cause some strange noises from time to time.

    As for the differential lube, I would stay with the weight that is recommended especially if you are in a colder climate. With that said, a good friction reducer or metal treatment can be used to help in these situations to extend gear and bearing life. Please forgive my shameless plug here, as we are distributors for CleanBoost® products. However, I have personally witnessed how CleanBoost® EMT™ (engine and metal treatment) works in open differentials. You can safely add 4 to 8 ounces to your differential and if your problem is even remotely related to friction or the reduction of heat, EMT™ will greatly diminish such a noise. Here is a direct link to check out CleanBoost® EMT™ – http://boostperformanceproducts.com/emt-metal-treatment/15-cleanboost-emt-engine-metal-treatment-8oz

    Good luck and keep us posted.

  104. […] time. Here is a good article with lots of good information. Understanding and Diagnosing Rear Differential Noise | Fuel & Friction | An automotive website d… Good luck, this should be a no brained for the mechanic at the dealership. 0 […]

  105. Rob says:

    Hi Tech Guy,
    Thank you for your thoughtful advice and insightful article. I have a 1996 Chevy Tahoe. I heard a grinding sound when decelerating bellow 25 MPH. I took it in, and got quoted 1600 to take apart and fix the rear differential. Im hesitant to put more money into this old truck and trying to assess my options. While I decide, I was wondering how advisable it is to drive the truck with this issue? Please let me know your thoughts. Thank you!

  106. james shouse says:

    hello tech guy. i have a 94 ranger pickup.it’s a straight shift. when i’m driving in 4th or 3rd gear, there’s slack when i let off gas pedal. what could be my problem?

  107. […] now. 1) Mopar1, Setting up a differential. 2) Randy's Ring and Pinion 3) Some good info from Fuel and Friction on diagnostics. 4) This was a great write up Bill Ansell put up on http://www.pirate4x4.com You tube […]

  108. Anonymous says:

    Hi, I own a 1992 gxl turbo diesel landcruiser i just drove from Darwin to Port Pirie and back my car has a standard noise at 95klm hour but it completely goes at 100klm and is very faint at 90klm hour I will be pulling out gearbox for bearing service and check clutch because we have to replace rear engine seal as we will be hitting the road for a year. I was thinking of using a thick oil stabiliser on front and rear diffs when i change the oil as when i had a 60 series i put in a larger gear in transfer case ( Mark’s conversions) cost $2500 all up and it was very noisy so i put the thicker oil which helped what are your thoughts on this as my very good mechanic who races dragsters and has one of the best reputation up here says all of this model with full time 4wd are noisy and tells me don’t stress. As I own 2 landcruisers I am very fussy about my cars. The noise sort of goes up and down in volume not so much its loud but a wearing noise like it has been driven at this speed alot (know what I mean anyway your thoughts would be great cheers Matthew Darwin NT

  109. Matthew Ireland says:

    Hi Tech guy, I just wrote a Q and forgot to fill in the bottom stuff, anyway I own a 1992 GXL Turbo diesel and i get a up and down noise in the drive at 95 klm per hr it completely goes at 100klm and 90 kml just at 95 and stays the same only at this speed.My mechanic will be replacing rear engine seal and bearings in gear box and check clutch as we will be hiting the road for a year . What are your thoughts on a thick oil stabiliser added to fresh Diff oils when changing front and rear as my very good mechanic say’s the all wheel drives are noisy anyway(will it hurt them at all) What do YOU think cheers Matthew from N.T

  110. Tech Guy says:

    Hi Rob,

    It’s hard to say for sure. I’m curious when you took it in if they actually pulled the rear diff cover and did a full inspect for your quote? Did they invite you to come on down and see the gears, gear wear, bearings, etc.? Or did they just take it for a quick spin and tell you that you need a full rebuild?

    I would get a second opinion or pull the rear cover for an inspection. If this noise has been present for some period of time… has it gotten louder recently? If yes, I would think it best to stop driving it until you can determine the problem or you may end up causing more damage to the components and/or housing possibly. Good luck and keep us posted.

  111. Tech Guy says:

    Hi James,

    Sounds like some excessive rear differential back lash. Check the rear pinion nut torque that it hasn’t backed off first. Also check your u-joints for excessive wear and slop. Good luck.

  112. Tech Guy says:

    Hello Matthew,

    Thanks for your inquiry! Since it appears that Toyota didn’t offer limited slip or locking differentials as an option until 1993, I would use a quality stabilizer or differential additive. The additional noise that some all wheel drives characteristically have is comprised of two components. One being friction and the other being inherit vibration due to all the moving components involved. If you choose to use a quality differential additive that has friction modifiers, double check that you do have open differentials. From what I can tell some models may have a limited-slip differential after all. If this is the case, also double check that the differential additive or stabilizer you choose is approved for such applications.

    Here is in the U.S. we have an additive which is really a metal treatment of exceptional quality called CleanBoost® EMT™ (Engine & Metal Treatment) In all transparency, we are distributors for it, so please forgive my shameless plug. However, as good as EMT is… I would not recommend it for most factory limited slip differentials since it works almost too well and will reduce the friction that is required for correct operation in these designs. So caution is warranted in these applications and that is why I recommend that you check that out first. Hope this helps and good luck on your one year road trip! Cheers!

  113. Vinnie says:

    tech,I have a Nissan vanetti minibus,it happened to have a leakage at the diff and had to drive it a long distance to find a mechanic…now the problem was fixed and oil was topped up and since then it has developed a whirring noise which increases as the vehicle accelerates but goes off when the transmission is in neutral…. what might be the problem

  114. Tech Guy says:

    Hi Vinnie,

    It may have developed this whirring noise due to running excessively low on differential fluid. The gears can become hot and wear an uneven pattern after a prolonged period of time without the proper lubrication in the differential.

    Please forgive my shameless plug as we are also distributors of CleanBoost® products here in the U.S.A., however, you would do well to get your hands on some CleanBoost® EMT™ (Engine & Metal Treatment) and add it to the differential to help quiet things down and reduce friction. You can learn more here: http://boostperformanceproducts.com/28-oil-additives

    Thanks for your question and feel free to keep us posted.

  115. Lacey Blue says:

    Hi Tech guy,
    I have a 93 Dodge Dakota & I’ve only tried driving it once the person I bought it from said it needs a new pinion bearing, I drove it a couple blocks & when I got to like 4-5 mph it clanked really bad. I instantly stopped & then drove it 1 mph the rest of the way. I’ve considered & do plan on replacing the whole rear end however times r hard right now. I’m about to flush the differential fluid to see if that helps but Is there anything I can do to. Any advice you would recommend I greatly appreciate.

  116. jason says:

    Hello Tech Guy,

    I have a 2006 Toyota Tundra 4.7L Full cab w/160k miles – just recently noticed that when decelerating a loud noise was coming from engine compartment (much like if you’re late to shift) and the rpm needle seems to be lagging/hanging up around 2k. The same humming sound is heard between 70-75 mph – and finally the truck shakes and vibrates like Boeing 747 when coming to a stop. (Checked drive-shaft, brakes/rotor/drums, and tires all good) – Thoughts?

  117. Bill Chapman says:

    I have a 1955 chevy bel air, just put aa ls motor in it and have a rear end whine, where should I start to dheck?

  118. Chiedu Onochie says:

    Mercedes Ml500 2003 developed grinding and banging noise at the rear especially at speeds lower than, 30 miles per hour. I replaced the rear u joints but made no differential. I do not know if it is coincidental anytime my car is jacked up there seemed to be some respite for 3 or 4 miles. When I completely stop the rear appear to seize released by sustained pressure on the accelerator pedal.
    Your advice will be appreciated.

  119. terry stewart says:

    Hi Tech guy I have Mustang GT 2010 when let off the gas and slowing down and between 50 and 40 I hear a whining in the rear end its a auto Tran. And I can put it in nuetrial and stops its not real loud yet I was wondering what your thoughts are. Thank you

  120. hi, i have same problem with bump after going at a green light, did you ever get an answer?

  121. Jackson B says:

    We have a 1982 Toyota Land Cruiser FJ45 with full float rear end that at highway speeds of 55 mph with a engine RPM of 2750 and above will start to make a very steady hum or rumble sound from the rear that has a definite rotational pitch, as the sound occurs at the 180 of a 360 degree revaluation and will almost dissipate completely with a small or large amount of acceleration remove from the pedal or when I push in the clutch and cost. The sound described is steady with no change in any turn at that speed of 55 or above. Cannot be tires if it goes away when costing from 55 mph, driveline was rebuilt and balanced with new center tube due to some bad dents and had new u joints installed at the same time. Has new pinion mount nuts and staked when installed and the differential was drained and filled with 90wt gear oil just mid last year. The sound kind of just stated being pronounced in the last few months and rarely is driven on the freeways or above 55 mph.
    Thanks much

  122. Tech Guy says:

    Hi there,

    It sounds like you’re on the right track with removing the rear differential cover, draining (also look at the drained fluid to see how many metal fragments may be included) and a good close visual inspection. Depending on what has failed, it may be still cheaper to replace components than to replace the whole rear end. Even used ones may have issues as well, so just be cautious. Best of luck and keep us posted.

  123. Tech Guy says:

    Hello Jason,

    Interesting… just for fun, have you checked the fan clutch on the engine? These things can really get loud and obnoxious upon lockup or bearing failure. Also, double check the front rotors for run-out. Sounds like they may have gotten warm (really warm) at some point and are now warped. Just some thoughts! Good luck and keep us posted up.

  124. Tech Guy says:

    Hi Bill,

    I would begin by checking the rear pinion nut for correct torque or possibly a ‘backed off’ condition where it has loosened from it’s correct setting for the backlash on the ring gear. In these cases, often the rear pinion seal will be leaking as well, indicating that the pinion bearing is allowing for additional play. Best of luck and keep us posted up.

  125. Tech Guy says:

    Hi there,

    Have you checked the rear differential fluid level and condition? Great place to start. If you end up draining and flushing, take a good close look at the fluid to see if any metal fragments are in there as well, indicating additional inspection and repairs. Good luck and feel free to keep us posted as to what you find out. Best!

  126. Tech Guy says:

    Hi Terry,

    How much hot rodding has this ‘stang been through? I would first check to see if the pinion nut has backed off at all from it’s factory setting. It could be that the ring and pinion have some significant wear patterns that have developed and are in need of a possible replacement. An inspection of the fluid and gears/bearings would be a good thing too just to be sure. I’m assuming that you have the 8.8 rear end in this GT, they are pretty rugged, but have been known to get loud as they wear or were subjected to hard punishment and/or fluid starvation. Thanks and good luck!

  127. Tech Guy says:

    Hi Gina,

    Not sure what your question was, but just from your comment, I would have the rear pinion nut checked and inspected for proper torque and that it hasn’t backed off. Sounds possibly like you may have excessive back lash in the rear differential. Best of luck and take care.

  128. Tech Guy says:

    Hello Jackson,

    Double check for wheel bearing failure or getting close to failure… especially on a full float design. You may need to take down for a visual inspect of both the inner and outer bearings and races. Best of luck and keep us posted on what you find out.

  129. Joshua Venable says:

    Have a constant clunk when driving every few feet only when it’s under torque but not when I’m coasting took the diff cover off no chipped teeth or fragments in housing not sure what’s making it clunk u joins are also good like I said constant clunking and popping noise while under torque 91 suburban with 342 gears and a detroit locker limited slip diff

  130. Kai says:

    Hi Tech Guy I have a 2009 ford fg xr6 and just had the diff clutches and bearings replaced In it and I have put the diff back in the car and took it for a drive and when going slow and then Speeding up there is a grinding clunking noise coming from the left rear side of the car and it also happens when I turn right or left from a stop I can not figure out what the problem is just hoping You know something about this thanks

  131. Qadeer Ahmed says:

    Hi Tech guy, i have a ford explorer 2004. i have had it for a few years. after driving for about an hour and when the car is fully warm, if i take a corner whilst accelerating slowly i hear a vibrating noise from the rear. my tires are fine. the car runs smooth is straight lines. I only get the noise when turning under acceleration or power applied, as soon as i remove my foot of the accelerator the vibrating noise disappears.
    when i drive it to work and back on a daily basis the drive is less than an hour I don’t hear any noises whilst turning. The vibrating noise is only evident after a long drive and whilst turning.

  132. abu says:

    Hello There,
    I have a Subaru Forester 1999 JDM, only on acceleration i am getting the noise which i believe coming from the back. When i stop or parked if i accelerate then i dont get any noise, but when i am driving ,the moment i accelerate i get the noise….i checked with the mechanic they told me to replace the rare differential which will cost me total 600 dollar (300 parts and 300 labour) now i want to find out if i put a new fluide will the sound go away? anyone tried just changing the fluide? ……i found a video in youtube … https://www.youtube.com/watch?v=Nz0uZQXkYzc this is exactly the sound i am getting…… can fluide change solve the problem for couple of months?? please reply…thank you

  133. Tech Guy says:

    Hello Abu,

    That is one loud rear end! Sounds like it’s either out of fluid, or the pinion nut has backed off possibly. So double check both of these. If it’s not a limited-slip differential, you could try CleanBoost® EMT™ located here. I do represent the company, so forgive my shameless plug, however since EMT™ attaches itself to the metal asperities to create a thin film barrier, it sure couldn’t hurt. Also, a fresh drain and new fluid fill would be a good idea before going to the expense of a new or replacement rear-end. Good luck and keep us posted.

  134. Tech Guy says:

    Hello Joshua,

    It’s hard to say, however I would be looking closer at either a complete bearing failure or the Detroit Locker as the source of the ‘clunk’. Hope this gives you an idea and you’re able to discover exactly what is causing this.

  135. Tech Guy says:

    Hello Kai,

    As long as the diff clutch and bearing repair went well and was installed correctly using the correct fluid, I would be looking at the outer wheel bearing assembly. They have been known to fail and give off a noise similar to what you’re describing. Best of luck and keep us posted.

  136. Tech Guy says:

    Hello Qadeer,

    Sounds like a couple of possibilities. I would start with a close inspection of the wheel bearings, they do have a tendency to make a noise as you describe with high mileage vehicles. These can be tricky to correctly diagnose visually, so really take some time and raise the vehicle in the air, support it safely, and rotate the wheels to feel for any roughness, looseness or ‘play’ or any noise. Finally, the limited slip differential clutches and/or bearings could be the culprit as well. So again, a close inspection with the differential cover removed and looking for signs of wear are key. Good luck and keep us posted.

  137. I have a rear end whine on 1996 cadillac fleetwood brougham. My mechanic put in all new parts, everything, including all bearings. This has been going on for a year now. It whines the loudest at the 45-50 mph range, when turning left, the whining goes away, that should tell the mechanic something, but he makes adjustments and I still have the same problem, leaving my mechanic scratching his head. When I brought the car in the first time, it had no whine at all, just a louder clunk when shifting. I thought it might be a universal joint but was told it was the rear end and it needed replacement. So, what in the world can I do? Mechanic backs up his work, so he is losing money on this fix also.

  138. Anonymous says:

    Hello Tech Guy, I need your help please. I took in my 1991 BMW 318is all original with 167k mikes into my local European specialist guy to replace everything underneath(bushings, suspension, brakes with lines, rear cv axles etc) bc it was all original and I want to keep the car in my collection forever. After thousands later I get the vehicle back only for it to be making very loud and deep hum/whoosh with acceleration and decelerating. Keep in my mind it was driving perfect before bringing it in for this maintenance work to be performed. Come to find out they finally figured out that the noise is coming from the rear end. They said they are not responsible for this but they did drop the subframe and also took out the rear end as well. My question is could they have mishandled the rear end somehow? I did see it slammed on the work bench not gently and was on its side for extended period of time. Again I’ve owned 7 bmw e30s and all had original rear ends with no problems at all and this drove perfect before they touched it with all of this work. They didn’t even test drive it after they gave it back to me and even a second time as well only for me to bring it back 30 seconds later each time. It’s at the shop now and they are not wanting to take responsibility for the rear end noise and idk what to do or how to handle the situation now. This bmw is specific in its rear end as well with being 4.10 lsd small case . I’ve spent thousands with them with all of this replacing of items to keep the car forever and did not have any problems before bringing it in to them. Please help!

  139. Tech Guy says:

    Hello Michael,

    I would ask if they replaced the ring and pinion gears as a set? Just on the surface of your question, they may have replaced all the bearings, and in doing so, this requires complete disassembly of the rear end. It is very difficult at that point, unless your technician is very, very good at setting up rear-ends, to get the wear pattern back to its original and exact position. If this isn’t the case (which happens more often than not) it will try and make a new pattern which always results in a rear-end whine. Check it out with your mechanic and keep us posted.

  140. Tech Guy says:

    Hello Anthony,

    I don’t know that they necessarily mis-handled, although it is possible. I would be taking a closer look at how the rear end and sub assembly is lined up to it’s original position and possibly causing pressure on the rear pinion gear from the drive line angle. Also, double check all insulator bushing replacements to be an exact OEM replacement and installed correctly to hold the rear end from moving under acceleration, causing an undue stress on the rear pinion gear bearing at the front of the differential. Another thing to look at would be the replacement cv axles, BMW’s use a very specific axle assembly and it’s possible that new replacements are not engaging the differential side gears correctly, either too deep or forcefully installed and this is now an issue causing a possible binding effect on the side gears to the pinion gears. Good luck and keep us posted.

  141. I have a 2007 ford f-150 fx2 pickup truck I hear a loud roaring or rumbling noise it sounds like it’s from the rear end, it makes a loud rumbling or roaring noise while driving but goes away when you shift it into neutral, what could be my problem?

  142. Cori says:

    Hi Tech Guy
    Your expert opinion is very much appreciated. I have a 2008 Jeep Grand Cherokee that have over 110,000 miles. Driving at 55 to 60 speed, I hear a whirling mainly coming from the left side rear wheel. I’ve already take it to Sears Auto Center and they stated that it wasn’t the wheel bearing but I need a rear differential replacement which they cannot fix because they do not have the parts. I took it to the jeep dealership and they said to inspect it would cost $260 which will go towards the cost of the vehicle to be fixed. Without the rear being opened or inspected they said depending on what is wrong, it can run from 1700 to a couple of thousands in price. Am I being scammed or will just need fluids. the whining noise is not loud and there is no bumping noise but you can hear it as I increase my speed.

  143. Tech Guy says:

    Hello Cori,

    I would still be very suspect of a wheel bearing. Have someone else drive while you listen from the back seat perhaps on both sides to see if one side is louder than the other. If after this… you still believe it to be coming from the left rear, I would go and get another shop to give you their opinion and repair estimate as well. Never hurts to get another opinion. I would also recommend a fluid drop and change especially if you take this Jeep off-road at all. Thanks and keep us posted.

  144. Tech Guy says:

    Hello Sterling,

    It could be that a rear pinion nut has backed off allowing the pinion gear depth to have changed slightly. Have this inspected looking for this condition and that the nut is at the factory torque spec. Also, take a look at the fluid in the rear differential for signs of any metal fragments or discoloration. May be time to do a fluid change/inspection by removing the rear differential cover as well. Thanks and keep us posted.

  145. Jiriah Dozorec says:

    HI tech guy
    I have a 2004 mustang gt, had 3.73 installed and it was great for the first few tank of gas then just yesterday goin down the highway I heard a very loud clunk, the clunking noise got worse and worse as I drove and it felt like it wanted to lock up it got so bad. There is diff oil leaking out and very loud grinding noise when the car is moving. Will I need a whole new diff?

  146. Tech Guy says:

    Hi there Jiriah, If a shop did this for you, I would be taking it back for them to inspect as to what happened in that short of time. Something was not set up correctly, or replaced as it should have been, or possibly wasn’t filled with gear oil to the correct level. Thanks and keep us posted.

  147. JJ says:

    Hello tech guy, I have a 2004 gmc Yukon slt 5.3 with 133,000 miles & I have noticed a howling noise only on acceleration from about 45mph -55mph(it sounds like after 55mph it could be drowned out by engine noise) but it’s disappears on deceleration & I do not hear this noise at any time before 45 mph. Thanks

  148. Val says:

    Hi tech guy!
    I have a 2008 jeep cherokee laredo. Recently, extremely loud rumbling sound from rear end, mostly only on acceleration, would the rear differential need rebuilt?

  149. Karla Nicole says:

    Hey tech guy, this is a great read. i have a 2015 jeep wrangler unlimited and my rear diff and pinion seal have just failed me. I was having concerns earlier this year and didnt see any signs of leaking diff fluid. Now i do have a 2.5 inch lift and 34.5 inch tires. I recently drove to ontario on a roadtrip and upon my return i began to hear an unusual sound from the rear. Could my lift cause my rear diff to fail?

  150. Timothy says:

    Hey tech guy, i got an 86 F150. Its not missing it has all brand new spark plugs and wires. But when i take off it struggles a bit and it will start to wobble and hop as i accelerate into a gear but once i am at idle speed in that gear it calms down. Also it seems to have had a loud noise coming from underneath kinda like tires that shows up about 20mph, gets a little quiet or more distinct while turning left i believe. It worked great besides the noise until yesterday. I spent time putting new valve cover seals and everything and whent to go home and it runs like crap. Motor is great it revs up in park or nutreul with no sounds or anything. I was reading and i believe you said if my gear box is low on gear oil it will make those sounds. I checked underneath and the rubber seal going out of the box into the shaft is worn out and fluid was leaking. More than likely has been empty for a little while now that i think about it. Also the U joints were bone dry, my truck has 3 of them and only one has the grease fitting. Please if you have any extra information it would be much appreciated

  151. Jane Poole says:

    Hi we have a Kia sorrento with a whining noise all the time which we were told could be a wheel bearing which has been replaced but still have the noise and it is gradually getting louder. A mechanic did say the differential looked dry added oil but still have the problem – this car has too many bearings trying to pin down where the problem.

  152. Manolo says:

    Hi Tech Guy,
    Above is a ton of wealth for all readers. Much thanks to your expertise. Would like to get your 2 cents… 2008 suburban ltz with whirring sound accelerate/decelerate, stepping/leting go off gas pedal at 40-60mph. Took to 2 diff shops and diagnosed sound coming from rear diff. Had rear diff overhauled, had all bearings and spider gears replaced, except ring & pinion (which, accdg to mechanic looks solid). After 1week in shop and $$$$, whirring sound is still there. Worst part, mechanic at a lost to solve problem.

  153. Gary Olney says:

    Can a bad Diff sound like it's coming from the front of a 4 wheel drive truck

  154. Gary Olney says:

    Can a bad Diff sound like it's coming from the front of a 4 wheel drive truck

  155. jeff says:

    I have a 2001 chevy blazer 4×4. It sounds like a clunking coming from the rear end or axle every 2 or three feet when in drive. It gets worse when I pat the gas in drive but not really in reverse. The sound is still there in reverse but no where near as bad. Plz help me out because im tired of sinking money into this ride but need it fixed

  156. Kurt M says:

    Hi tech guy,

    I have a 2002 Ford F-350 4WD super duty, single rear wheel. I have a low hum noise at 20 – 40 kph from rear diff.
    ( new pads and rotors – nothing binding there)
    I jacked up and ran in gear – hum is in time with wheel rotation. When i lower one wheel at a time to the ground with the other spinning the hum stops – same on either side.
    ???

    Thoughts?

  157. Tech Guy says:

    @Jeff, Sorry to hear about your rear differential troubles on your Chevy.
    I would drain the gear fluid first and look to see if the old oil has any metal fragments or friction materials in it. This way, you can determine quickly if it’s in need of mechanical repairs. I would be looking for damage to the side/spider gears or possibly the ring and pinion as well.
    Sometimes, it can be as simple and cheap as a fresh fluid change with a quality 80W90 GL-5 hypoid Gear Oil. Then top off with CleanBoost EMT. The EMT (Engine & Metal Treatment) will penetrate the metal and provide an improved mating surface combined with less friction and heat,which in turn should help to reduce the noise.

    You can purchase CleanBoost EMT here: http://boostperformanceproducts.com/28-oil-additives

  158. Tech Guy says:

    Hi Manolo,
    Thank you for the kind words.
    After reading your story I can say that the ‘whining’ sound during acceleration/deceleration can be caused by excessive backlash from the ring and pinion setup… since these 2 were not changed you could consider checking them out to see if maybe a pinion nut has essentially ‘backed off’ from it’s factory setting.
    It’s probably best to have the rear differential inspected by draining/removing the rear cover and looking for the signs of ring & pinion wear, excessive backlash. Here’s a great YouTube video on how to drain and fill your rear differential just to help you with a reference of inspection: https://www.youtube.com/watch?v=KmqMUJb-E4M
    Also if you drain the gear oil you could also try to re-fill with a quality 80W90 GL-5 hypoid Gear Oil, then top off with CleanBoost EMT. The EMT (Engine & Metal Treatment) will penetrate the metal and provide an improved mating surface combined with less friction and heat… which in turn should help to reduce the noise.
    You can purchase CleanBoost EMT here: http://boostperformanceproducts.com/28-oil-additives
    If you’re lucky you will solve the issue with a simple change of oil.
    Best of luck!

  159. My name Manny & I Have a problem with my 2003 ford F250 super duty every time wen i shift to reverse or forward the Differential move to a point that i can hear the click noise some one please tell me how to fix this problem thank you

  160. Hello – i have a 2007 Freelander 2. I recently had my differential replaced for a brand new unit but since my car's return it made a 'clunk' every time i engaged reverse. it now sometimes makes the clunk when i move forward (or forward while turning right). the dealership cannot diagnose the issue. any ideas?

  161. Hello Tech Guy I have a 2003 ford F-250 super duty I been haven this problem with my truck rear differential wend I shift forward or reverse I can see the Differential move up & down i can heard a clock noise can the left springs cues something like this to the differential I see other trucks & I don't see the problem I have please help

  162. hello Gary Isean other trucks like mine they don't do that I olmost want to put new leaf spring to what happend I took the truck to check the 4×4 & it's okay i fogot to askthe mechanic for the diff

  163. hello Gary Isean other trucks like mine they don't do that I olmost want to put new leaf spring to what happend I took the truck to check the 4×4 & it's okay i fogot to askthe mechanic for the diff

  164. Tech Guy says:

    Hello JJ,
    Howling noises at speed over 20 mph, can be the result of worn carrier bearings. You should check the bearings and pinion setup.Here’s a great YouTube video on how to drain and fill your rear differential just to help you with a reference of inspection: https://www.youtube.com/watch?v=KmqMUJb-E4M
    Best of luck and keep us posted!

  165. Tech Guy says:

    Hello Val,
    The rumbling sound might be from worn carrier bearings. I would open it up and check for abnormal wear, check to see that the rear pinion nut has not backed-off from its factory torque setting and then check the fluid, drain and add new fluid.
    The rear pinion nut can sometimes loosen and can cause the pinion depth to change its angle just enough to start ‘creating’ a new pattern on the ring gear and that could be what you’re hearing.
    It might be better to take the vehicle to a professional due to the complexity of the repair. Good luck and please keep us posted.

  166. Tech Guy says:

    Hey Karla, It’s best to lift your Jeep using products that correctly ‘cant’ the rear pinion angle back to the factory setting. Sometimes, if you simply install spacers above the rear coils, you can upset the factory angle enough to cause stress on the rear pinion. Hope this helps and keep us posted.

  167. Tech Guy says:

    Hey Timothy,
    I would recommend you to check your differential fluid, drain it and add new oil. Sometimes this little trick works wonders.
    About the sound that is more distinct while turning left could be a sign of bad wheel bearings.
    Also change your gearbox oil seal immediately. Running on too low oil levels can cause serious damage to your gearbox.
    The U joints work best when they’re lubricated. I would recommend grabbing a CleanBoost High Temp Grease (link here : http://boostperformanceproducts.com/home/31-cleanboost-mettle-plus-ep2-high-temp-grease-14-oz) that will help you in any conditions and generously apply it. Replace the U-Joints that have no grease zerk fitting if they have any play or signs of wear.
    A few tweaks here and there and you should be back on the road. Please keep us posted. Good luck.

  168. Tech Guy says:

    Hello Jane,
    Sounds like you should check and see if all the seals from the differential are okay and you’re not losing fluid there and top off if low.
    The noises could also be from excessive backlash from the ring and pinion setup… combined with a noise of metal rubbing or grinding, could be a pinion nut that has essentially ‘backed off’ from it’s factory setting. Finally, if this car can be put on a lift, using a stethoscope, one can pinpoint most bearing noises to isolate which bearing may be the culprit. Good look and keep us posted.

  169. Tech Guy says:

    Only if you’re in 4WD. If in 2WD, and it sounds like it’s still coming from up front, I would be looking at the front wheel bearings. If this is a part time 4WD system, the front differential will not be turning at all while in 2WD mode, however, if this is a fulltime 4WD or AWD system, it is indeed turning all the time and will be a little harder to isolate. Good luck and keep us posted.

  170. Tech Guy says:

    Hello Kurt,
    Hum noises at speed over 20 mph, can be the result of worn carrier bearings. You should check the bearings and pinion setup.Here’s a great YouTube video on how to drain and fill your rear differential just to help you with a reference of inspection: https://www.youtube.com/watch?v=KmqMUJb-E4M
    When you put one wheel on the ground, you essentially are forcing the spiders and side bearings to run full speed, which if they have wear, will hum and whine possibly if they are either worn, damaged or low on fluid.
    Best of luck and keep us posted!

  171. Tech Guy says:

    Best to inspect the rear u-joints first, followed by a rear pinion nut that may have backed off from its factory setting and allowing for excessive backlash. Good luck and please keep us posted.

  172. Steve says:

    Hey tech guy. Is it at all possible that a bad rear end differential is the cause of my transmission slipping?

  173. Tech Guy says:

    Hi Steve,

    The only way this could be possible is if all the teeth are destroyed on the pinion an/or ring gear. It is rare indeed, but possible. I would be looking at either your clutch (if standard) or torque converter (if automatic). Best of luck and keep us posted.

  174. Austin says:

    Hey Tech Guy,
    I have a Jeep TJ with a manual transmission. The rear diff grind when coming out of first sometimes from a dead stop but then goes away when i take off. It is worse when there is applied pressure such as sharp turns and going up a curb from a dead stop. However, it only does it if I drive it for a while or a long distance and it gets hot then it will do it. I replaced all of the rear U-Joints but that wasn’t it.

  175. Austin says:

    Hello Tech Guy,
    I have a Jeep TJ with manual transmission. When I am at a dead stop and come out of first gear the rear diff will grind then goes away once i get speed. It is worst when i make a turn or climb up a curb where there is applied pressure from a dead stop. It predominantly does it when i drive it for a while and the it gets hot then it gets worse. Replaced rear U Joints and didn’t help. Any thoughts on problem? Thank you for your time.

  176. Just bought 2008 infiniti qx56 has swerve in back while driving sometimes. Service just changed out hub bearing assembly in back. Vickie

  177. Bo Andrews says:

    Hi tech guy,
    I just started having loud noises coming from my rear end so much that i dont fell comfortable driving it. It’s a 99 Ford f150 and has about 150k miles. I suspect either something in the break system broke or there is something wrong with my rear dif. I have owned it for 2 years now and have never had any problems or sounds coming from my rear end. So my question is could something of happened to the rear dif within one day that could of caused it to make loud noise or is a rear dif problem something that you will notice over time and gradually become worse? And if it’s not the rear dif what else could cause loud noise from the rear end with no prior problem?

  178. Tech Guy says:

    Hello Bo,
    From what I can tell you have to further look into it to be 100% sure where the noise is coming from. It can range from your wheel bearings all the way to the spider gears that might be close to break down. If the rear end noise is characterized by clunking every two or three feet, then there is a great chance that a broken ring gear is the problem with the section with the broken teeth banging or grinding as it tries to engage the pinion.
    Do you experience loud noises from the rear end all the time? Or is it just when accelerating/decelerating ?

    Best to do a rear differential inspection by dropping the fluid and rear differential cover. Take a close look at all the components for extreme wear or broken pieces or metal fragments. Good luck and keep us posted.

  179. Tech Guy says:

    Hey Vickie,
    In order to track down the problem you might have to take the car back to the service and have all the rear differential and axle mounts closely inspected to be sure they are not moving and allowing the rear end to move under side to side load.
    Please keep us posted and good luck!

  180. Tech Guy says:

    Hello Stephen,
    Since you recently had your differential replaced and still encounter “clunk” sounds then you should double-check its preload and make sure the teeth are properly aligned.
    Also, check to be sure the U-joints are tight and not allowing for any unnecessary play in the rear driveline.
    Keep us posted.

  181. Tech Guy says:

    Reply to Austin:

    Best to check the rear pinion nut for a ‘backing off’ condition whereas it may have lost it’s factory preload setting. Next, check the rear differential fluid condition and level. Replace with fresh recommended fluid. Good luck and keep us posted.

  182. Patty says:

    My motorhome has a Ford V10 chassis not under warranty but only has 14K miles.Brought in after hearing howling in rear, extended warranty had bme pay for 2 hour diagnoses. Report by tech to warranty fluids were all good debris on magnetic plug. Now ex warr is asking me to have it torn apart before they determine if they’ll cover it. Ford state they don’t need main till 60K how do I get records to prove Fordshould pay if this turns out to be a common problem? Also tech said sway bar in missing a bolt and it’s bent. Could and accident cause the sway bar to bend? Tech says wrong torc at factory. I’ll hold off crying till you tell me good news lol

  183. Iam hear a whining noise in rear I thought it was the tires and and vibration noise and at a certain speed a clunking or a thumping noise?

  184. Tech Guy says:

    Hello Gary,

    If this is a part time 4X4 truck, and you’re in 2WD (without the hubs engaged as well, so that only the front wheels are turning and not the front driveline), then probably not the differential itself. However, could be wheel bearings. Good luck and keep us posted.

  185. Tech Guy says:

    Hello Juan,

    This condition can be caused by excessive ‘spring wrap up’ or loose clamps for the rear axle, combined with excessive pre-load on the rear pinion. Best to have these items inspected to be sure. Good luck and keep us posted.

  186. Tech Guy says:

    Hi Patty,

    On the surface, it sounds like some premature wear on the bearings and/or gears of the rear differential. Since the fluid levels were good and the fluid itself in decent condition, I would have a hard time not believing that the extended warranty would cover such a thing as long as it is spelled out in their warranty contract that it is a ‘covered component’. Check over your contract for the small print to be sure as well. Also, when reviewing your contract, look for what is and what is not covered of a ‘covered warranty’ item. For example, some pay for fluids, some don’t. Some pay for X amount of hours and nothing more, or even only a flat rate or pro-rated amount. Good luck and keep us posted.

  187. Tech Guy says:

    Hi Rich,

    Best to begin looking at fluid levels in the rear differential, followed by a thorough inspection of the rear wheel bearings. I have seen wheel bearings throw off some of the better technicians out there, just saying… so really pay attention to ‘where’ the noise is coming from to pinpoint the problem. Good luck, keep us posted on what you find.

  188. David says:

    2015 Dodge 2500 diesel. I’m hearing a howling at 60+ also at any speed the truck feels like it’s slowing down when I remove my foot off the gas. Not a normal slowing down, rapid decrease in speed. under tow it shakes really bad in the rear. It also has decreased in fuel mileage under tow and normal everyday driving. Dodge has it says nothing is wrong with it when I got it back. There is a vibration while on the interstate at 55+ mph. It only happens when it is driven 10 plus miles then it really starts acting up bad when the rear end heats up.please help.

  189. David says:

    The fluid was changed by Dodge 1month ago

  190. Tech Guy says:

    A: Hey David,
    I think it’s overheating due to either a clutch problem from the limited slip or a real mis-alignment problem with the gears.
    Best thing to do is to open it up and do an inspection of the components looking for abnormal wear and/or broken clutch packs in the limited slip
    Hope this helps! Please keep us posted.

  191. Iltizam says:

    Dear Tech Guy. I have Hyundai Terracan 2001. 4X4 drive. After broken of one tyre, I had replaced two rear tires with used tires. Seems measures were the same as previous ones. I started to drive. Then I heard strong noise from rear differential. I drived car about 200 Km and tried to learn noise problem from professionals . As a best solution, I removed front shaft from front differential and continued driving car with only rear driven method about 10000 Km. When I recognised that diameter of rear tires are 15mm less than front tires, stop car, changed all tires with new tires. Now I am interesting with that, will not have any problem, if I re-fit front shaft? Are there possibility to stop strong noise from rear differential ,after replacing front shaft? Thanks in advance: Iltizam

  192. Tech Guy says:

    Hello Iltizam,

    15mm is enough to stress the drivetrain if it is a full-time 4X4 and operating on dry pavement. Hopefully, it should all return to normal after installation of all 4 matching, new tires and replacing your front driveshaft. Good luck and keep us posted.

  193. Dan says:

    So I have a 2007 Ford Edge SEL that have about 150,000 on it and it’s starting to make a grinding noise when I accelerate but when I stop and ease on the gas the grinding noise stop. Any suggestions what that could be?

  194. Tech Guy says:

    Hey Dan,

    Sounds like a rear pinion bearing as this is a common culprit of grinding noise/whine during acceleration. The bearing wear is allowing the pinion to move just enough that it is trying to cut a new pattern on to the ring gear. Short of complete disassembly, there isn’t really a magic additive to permanently reduce the whining noise. Additives may reduce it for some time, but it will return most likely. The best bet is to inspect it and most likely repair and replace the worn and damaged components/bearings. Best of luck and keep us posted!

  195. Ricky Spell says:

    I’m getting a popping sound in the rearend of my 01 Yukon only during turning ND mostly to the left,hardly ever turning right. Could that be a broken spider gear?

  196. Ricky Spell says:

    I’m mechanical and can change out the housing in the rearend but I have some spider gears left over from changing the housing on my 07 Chevy Truck and I was really hoping to be able to take the cap off and replace the broken spider gears in my 01 Yukon. Will thone same spider gears work for the Yukon?

  197. Iltizam says:

    Dear Tech Guy. I have Hyundai Terracan 2001. 4X4 drive. After changing all 4 tires with new tires, replaced front shaft in place. So, I recognize another problem. Car is moving forward and backward smoothly as well. But, when I try to turn the car left or right, car is stopping gradually. Is it rear differential problem or front differential problem?

  198. Doug Raney says:

    Hello sir, I’m feeling like a couple of local repair shops are trying to pull the wool over my eyes and I found you while doing random research. Hoping you could shine some light. The vehicle is an ’86 Chevy S10 4WD with a weakling 2.8 V6. Brand new trans, 100% rebuilt transaxle, lots of new parts across rear axle, bearings, brakes, etc… the rear end rebuild is where I have the concern, need help. I paid $1900 for a total rebuild, every single part, positrac, 10-bolt. I picked it up, drove 300 feet and turned around due to the grinding noise when I turned the wheel a little. They checked it out and told me it was fine, that positracs make grinding noises and not to worry about it. I took it to a second shop who at first agreed that the noise was normal, but are changing their story now they seem to think they can get more money out of me. I can’t imagine grinding this loud happening without a lot of damage going on somewhere. I can feel it in my feet, like a shovel being dragged over asphalt, not kidding. The question is; do positracs typically make noise on turns or is this an indicator of big problems? Thanks!

  199. Tech Guy says:

    Hello Doug,

    On the surface, it sounds as though the shop that did the rebuild set up the positrac too tight. Have you had any success in getting this resolved as of yet?

  200. A Forster says:

    I have a 2003 chevy avalanche and came home today and put in park and when I put in drive felt like wheels locked up and then released. So I put my things in the house to see what going on and to park it well at first I still had problem slowly moving forward with no noise then I put it reverse and tried to accelerate and would move then back wheels spun out and move but now going forward or reverse very loud crunching and clanking and feeling like wheels stuck then move does this sound like I need new rear differential or any other suggestions thank you

  201. A Forster says:

    Another thing to add to my post above when in reverse and wouldn’t move then did with crunching sounds the message center was saying traction activated

  202. Tech Guy says:

    Hello there,

    It sounds like you may have a side gear or even pinion gear(s) that may have a chipped or missing tooth, could also be a ring gear with tooth damage. Time for an inspection by removing the rear cover and taking a good look. Here is a link by Chris Fix, that will help you with that: https://www.youtube.com/watch?v=KmqMUJb-E4M Good luck and keep us posted.

  203. Tech Guy says:

    Hello there,

    It sounds like you may have a side gear or even pinion gear(s) that may have a chipped or missing tooth, could also be a ring gear with tooth damage. Time for an inspection by removing the rear cover and taking a good look. Here is a link by Chris Fix, that will help you with that: https://www.youtube.com/watch?v=KmqMUJb-E4M Good luck and keep us posted.

  204. Ryan Corcoran says:

    Hi, I have a chevy 3500 dually with approx 150k on it and am getting a noise/vibration that starts around 30 and gets worse until about 65mph. Then around 70mph not as bad. It is more of a vibration than a noise and shakes the inside of the truck slightly. It is a little worse on decel than any other time. It was ran low on fluid due to rust holes in the rear cover. It doesn’t seem to be any better or worse when turning. It does have a 2 piece driveshaft with carrier bearing. Any idea where I should start looking? Thanks

  205. Ryan Corcoran says:

    I should also add that when the bad cover was removed and replaced there was little to no metal particles in the fluid, and there is no gear whine or howling.

  206. Tech Guy says:

    Hi Ryan,

    I would start by inspecting the rear driveline, carrier bearing & u-joints. These components are more common to succumb to metal fatigue and generally wearing out over time due to higher mileage. Even the slip yoke assembly should also be closely inspected as part of your discovery of these components and their wear patterns thus far. As I mentioned, it is not uncommon for these components to require replacement and maintenance. Also of note, is the fact that you had enough moisture in the rear differential to cause the rear cover to rust out. You should take precautions to avoid this by routine inspections after either extreme humidity conditions or exposing the truck to water in general through rains and/or fording high water crossings, etc. Best of luck and keep us posted.

  207. Tech Guy says:

    Hi Ryan,

    I would start by inspecting the rear driveline, carrier bearing & u-joints. These components are more common to succumb to metal fatigue and generally wearing out over time due to higher mileage. Even the slip yoke assembly should also be closely inspected as part of your discovery of these components and their wear patterns thus far. As I mentioned, it is not uncommon for these components to require replacement and maintenance. Also of note, is the fact that you had enough moisture in the rear differential to cause the rear cover to rust out. You should take precautions to avoid this by routine inspections after either extreme humidity conditions or exposing the truck to water in general through rains and/or fording high water crossings, etc. Best of luck and keep us posted.

  208. john fodor says:

    Hello Tech Guy, I have been driving a M Benz 2006 just over 100,000 K. on it. A couple of sensor problems. Now there is a oil leak about the size of a dinner plate on the driver side back wheel and on the passenger side one about the size of silver dollar. What sort of explanation can i look forward too from a very good Technician that does my work? I just had the entire ABS system replaced, all new parts and cloned.
    This is a Ml 500.

  209. Donald Codey says:

    My 2009 Jeep Cherokee has the whining noise. My dealer says that my rear tires are low on thread and this is the cause of the differential problem. Therefore it is not covered by warranty.

  210. Tech Guy says:

    Hello John,

    First of all I would recommend topping up or changing the rear diff oil. Running on low oil levels could​ ​severely affect your rear differential components, making it a very expensive fix.
    Then you should have them check the seals on the rear diff and change them if that’s the place where​ ​the leak is coming form.
    Other th​an this, you should be fine.
    Besides oil leaks, do you have any other problems? Like noises coming from the differential?
    Please keep us posted.

  211. Tech Guy says:

    Hi Donald,
    It would be best to look at the fluid levels in the rea​r differential and then do a thorough inspection of the rear wheel bearings. Often times these wheel b​ea​rings are the problem and they are hard to diagnose even for some of the better technicians. Tire tread should not be an element of this problem.

    Best of luck and keep us posted!

  212. jake says:

    I have a 95 f-150 2wd and had to replace my differential a few years ago because the center bearing went bad and the end result was damage to the case. The differential i got from a junkyard has made a grinding noise ever since i put it on. It only starts to grind when i reach about 25 mph, depends on how fast i accelerate. If i push the pedal to the floor it starts after my transmission shifts the first time. Ive been having trouble diagnosing if its the differential or transmission. Ujoints are brand new and differential fluid is good. Any advice would be greatly appreciated.

  213. jake says:

    Also has an automatic e40d transmission

  214. Tech Guy says:

    Hey Jake,
    Sounds like a rear pinion bearing (this is a common culprit of grinding noise/whine during acceleration) The bearing wear is allowing the pinion to move just enough that it is trying to cut a new pattern on to the ring gear.
    Besides complete disassembly, I’m afraid there aren’t any other options to permanently reduce the grinding noise. Using additives will reduce the noise but only temporarily. The best would be to inspect it and most likely repair and replace the worn and damaged components/bearings. Good luck and please feel free to keep us posted.

  215. Joseph says:

    Hello Tech Guy,
    I have a 2007 Jeep Grand Cherokee 108,000 mile original owner no lift, no off-roading.
    Had a pinion seal failure which created front and rear pinion bearing failure. Unknowing drove with bad pinion seal
    when bearing failure occurred probably only 32 ounces of gear oil in reservoir so assuming very high temperatures were achieved.
    Vehicle taken to a lisenced mechanic and front and rear pinion bearings replaced as well as races.
    now vehicle whines only during deceleration.Could the high heat achieved cause any of the whining noise or could it
    be that the preload was never achieved on the pinion nut?
    Any advice would be greatly appreciated.

  216. Steve Schuette says:

    I have a 2009 yukon with about 95000 miles had a whine decelerating between 65 and 45 . Took it in to a shop and the tech tighten the front bearing , crush sleeve, and when i picked it up , turning corners felt like bad spider gears, {not mesh correctly} But it has a g80 If I go around in a circle it whines whistles Should I take it back to the shop or put a additive or ? Any help would be great

  217. Tech Guy says:

    Hello Joseph,
    I’m more inclined to go with the latter. Sounds like it could be a pinion-bearing preload that wasn’t quite achieved, this is a more common deceleration issue. Not a guarantee however, since we don’t know just how much heat and friction was applied to the gears before the repair took place. It’s also rather difficult to get the exact pinion depth matched to what it was before, which does cause the somewhat famous ‘school bus’ whine that you’re referring too. Good luck and keep us posted!

  218. Tech Guy says:

    Hi Steve,
    You should not rely on additives for this particular issue since they would help to reduce the whining, but it will most likely reappear at some point, since this is a mechanical defect.
    Best advice, take it back to the shop and have them check it out a little closer for what could be binding or not setup correctly. Please keep us posted!

  219. Edward says:

    I have a 2003 Dodge Ram 1500 quad cab with Hemi. I recently had a remanufactured rear end installed with a drive shaft. A day after picking it up from the shop, I was hear a whining noise in the rear upon deceleration and a slight roaring noise on acceleration, at any speed. I took it back to the shop and the mechanic put something in the rear end that’s supposed to quiet the noise. He advised me to drive it for a week and the noise should go away. I’m nearing the end of that week and the noise is still there, slight better, but there. What is likely the issue here. Could it be the remanufactured rear end is faulty? Thanks in advance.

  220. Tech Guy says:

    Hi Edward,
    It sounds as the mechanic added a product to boost lubrication. Unfortunately this only works so much… the problem is more or less masked.
    The whining during deceleration and roaring during acceleration can be caused by excessive backlash from the ring and pinion setup… combined with a noise of metal rubbing or grinding, could be a pinion nut / crush sleeve that was not set properly by the remanufacturer.
    It would be best to inspect the rear differential by draining/removing the rear cover and looking for sign or ring and pinion wear, excessive backlash. There might be a probability that the remanufactured rear end is faulty.

    Good luck and please update us on this

  221. Gary says:

    Hi Edward,

    I have a 2011 Mustang and have had a shop replace the 273 gears with 355, I now have a whine especially on deceleration but it is also there under light load at certain speeds, I’ve never heard it under acceleration. What would your guess be as to the problem

  222. Chris says:

    Hi. I’m having severe problems with my 69 Lemans. Bought a used 12 bolt pos and installed. After driving a while…found missing tooth on ring gear. Replaced posi unit and ring and pinion. New bearings as well.
    I’m on my third time tearing it down. This is my first try at rebuilding one. I did not shim the pinion the first 2 times because there wasn’t one on the stock pinion. (Stupid…..I’m aware).
    Anyway…this…the third time….I used a ratech tool to set the pinion depth. It was .020 off. Shimmed it to manufacturer spec and then set backlash at .006. I put roughly 200 miles on during this whole process. I still have a light whine under light acceleration. ???
    I’m probably doing something wrong I know, but I’m confused by why my backlash has doubled or even tripled by the time I go to remove and recheck everything…..twice?? The second time I shimmed it where it was very tight side to side to install. When I removed it. It fell out.??
    Also….with a constant light whine…have I already destroyed this particular ring and pinion?

  223. Tech Guy says:

    Hi Chris,
    A couple of things to remember… inherently 12 bolt posi rearends are a little noisy, usually due to the fact of lower gears 3.73:1 and up to even 5.14:1 and beyond, due to less pinion teeth and steeper engagement angles. Secondly, did you set it up to factory specs or what the aftermarket gear manufacturer called for? They are different and it’s important to get those settings within their specified range. Nothing may be wrong if it’s just a light whine under acceleration as I mentioned. You can minimize it by putting in a high quality metal treatment such as CleanBoost® EMT™ found over at Boost Performance Products. If there’s really nothing wrong, it will work to minimize metal to metal noise, heat and friction. Good luck and keep us posted.

  224. Alex says:

    Hello Tech Guy, I have a little problem also with the car, a bmw x5 2011 , x drive 30d, 121000 km, I’ve been driving it from 97000km without any problem, some 3 months ago, while driving, suddenly came a high pitched sound and very loud, as if stone on metal or even metal on metal friction was going on in a wheel, I stopped the car and restarted engine, same sound on acceleration, I then put it in reverse and drive a few meters and there was no sound, after that there was nothing wrong or any suspicious sounds or vibrations with my car until 3 weeks ago when I went to service for electronic problem, they took one of the wheels off( front driver side one) to see some cable, fixed the electronic problem but on testing the car I discovered that on breaking only comes a rhythmic sound accompanied by a soft vibration as if you would slowly but firmly hit the wheel with a wooden hammer or piece of wood (very bad with describing sounds in English, sorry :), went back the day after to tell them about this, they checked the car and said it’s not anything dangerous but it can be the rear differential, got an appointment in 3 weeks ( they are a very busy car service). My questions are, do you think there’s any connection between that one time event 3 months ago and this sound on breaking ? or could the service guys have done some damage or mistake on taking the wheel of and putting it back ( because the sound wasn’t there before going to them) ? And do you think it’s safe to drive the car normally until it gets checked? Because I’m driving 60-70km daily.
    Also, forgot to tell…I’m not 100% sure about this but I may have heard a howling sound on higher speed, over 100km/h, but that is one time also and it was so weak that I’m not sure it really was there, may have very well be wind blowing on the car, I don’t know, but it didn’t happen again.
    Thank you very much! 🙂

  225. Paul Triplett says:

    I’m getting a scrubbing sound from my rear end of my 98 dodge ram 5.2l 2wd I don’t no how to tell what rear end is in it but it is a 12 bolt pattern. I just can’t figure out what the sound is

  226. Michael Brown says:

    Mike
    I have a 2002 f150 with a 4.6 engine, I am feeling a rumble (seems like its from the rear) when I am doing highway speeds and a knocking (intermittent) when slowing down (no load). My question is, could this be wheel bearings or brakes or should I be looking at the differential. Also wondering if being low in diff fluid could cause this. Appreciate any insight.

  227. Max says:

    Hi.i have 1984 Mercedes w123 230e
    I replaced all the differential bearings and preloads
    And still noise only when desacceleration
    I am confused there’s no back lash in it
    I am asking for your help
    May be the preload losens up??

  228. Mike says:

    I have a 2012 Grand Cherokee Overland with the 5.7 Hemi. It now has 85,000 miles but this ringing/whining noise started back at 55,000 miles or so. What’s happening is a loud ringing noise ONLY at 75mph and ONLY when under SLIGHT acceleration. It does NOT do the noise under 73 or over 77. It does NOT do the noise when coasting or going on a flat or downward slope. But since I usually have the Adaptive Cruise Control set for 75mph, as soon as the ACC adds just a slight amount of power the whine picks up again. It’s almost at a decibel pitch level that’s high enough to be considered a “rrrrrriiiiiinnnnnngggg” that really gets into your brain. And very annoying. If I accelerate hard, then the noise disappears. So it is strictly at 75 and strictly under a slight acceleration loud.

    Now here’s the tricky part. Because of unrelated issues, Jeep has already replaced the following:
    -Automatic Transmission
    -Trans Kit w/Torque Convertor
    -Trans Cooler & Condenser
    -O2 Sensors
    -Driveshaft, Transfer Case to Rear Axle
    -Replaced Rear Prop Shaft

    Still, after all of that, the noise is still there just like before even with all of the above work done. I was told by the owner of a heavy-duty truck transmission manufacturer that the Ring & Pinion should be checked “as it might be set wrong”. Does this sound correct to you?, or can you determine form these comments if there’s a more likely suspect? I know the Jeep mechanic is a perplexed as anyone and he says the pinion “looks” OK, but might it be an adjustment, or (from what I’ve picked up) the “angle” or degrees, that needs to be adjusted? Is there a certain component that would show wear specific to 75mph? I drove with the expert Jeep trans mechanic sitting in the back seat and he instantly heard the ringing whine and found it coming from the center-line tunnel right behind the front seats. BTW, it is clear it is not some unrelated thing like the roof-rack, windshield, or some other such nonsense. It is clear it’s a driveline issue of some sort, a bearing, bushing, (rear differential?), etc.

    Any suggestions?

  229. Tech Guy says:

    Hi Mike, I would be highly suspicious a rear bearing, side bearings, front or rear differential bearings. These bearings move under load even in the slightest. Unfortunately, it does require disassembly to inspect or replace any of these. Good luck and keep us posted.

  230. Tech Guy says:

    Hi Max,
    Yes.If you notice that the noise only occurs during deceleration, you have no sign of backlash then it is a good indicator that the pinion-bearing preload has loosened.​ Good luck and keep us posted.​

  231. Tech Guy says:

    Hello Mike,

    For the rumble feeling you should double check for wheel bearing failure or getting close to failure.
    You may need to take down for a visual inspect of both the inner and outer bearings.
    If you don’t discover anything there, you can check to see if a rear pinion nut has backed off allowing the pinion gear depth to have changed slightly. Have this inspected​…​ looking for this condition and that the nut is at the factory torque spec. Also, take a look at the fluid in the rear differential for signs of any metal fragments or discoloration. May be time to do a fluid change/inspection by removing the rear differential cover as well. Better to not run your F150 with low diff fluid.

  232. Larry says:

    I have a 2000 f150 4.2L just had to replace the 5 speed manual transmission due to a failure in the clutch and pressure plate that basically locked up going down the road. I am experiencing a popping like the rear end is getting in a bin ever few feet or turning. I have put new u-joints in. can you give me any suggestions on what the problem could be.

  233. bob says:

    I have a 2008 Chevy Impala. It sounds like the rear window are open and we hear what I believe is a tire noise. The car also vibrates, you can feel it in the seats.
    Can you help?

  234. Tony Houben says:

    Afternoon. I have a 1999 LN167 hilux. I have slight noise from rear diff when towing trailer. I thought it was small movement in the coupling ball in the tow bar but I can now hear the same noise without the trailer. It sounds like it is clunking from standstill to 5km/h. I also thought it was my mud grip tyres but ive never had this noise when I first out the tyres on. Please help. Regards

  235. Tech Guy says:

    Hello Tony,
    It sure doesn’t sound as a problem coming from the tires. Regular clunking noise can indicate a ​excessive backlash on the pinion gear. Could be that the pinion nut has backed off from its factory setting.
    You should open it up and check the internals.
    Please keep us posted

  236. Tech Guy says:

    Hi Bob,
    Vibration might come from one of your rear wheel bearings.
    Also do you feel that the vibration intensifies when applying the b​rakes? If so, the vibration might come from your disk b​rakes. Under pressure they can overheat and warp, thus becoming wobbly at higher speeds and making your car vibrate. Also this could happen if you did not move your car for a while.
    ​Let us know what you discover!

  237. Tech Guy says:

    Hello Larry,
    Since you are experiencing popping like sounds while turning, I would dare to say that maybe the limited slip is acting up and/or you have a damaged side/pinion gear in the rear diff.
    Best bet would be to have it inspected and also check fluid levels in the diff. If needed, replace the gasket and make sure to add fresh fluids.
    Feel free to keep us posted. Your info might help other too

  238. jake says:

    Hi there,
    I have a 2002 F-150 which is making steady squealing (eeeeeee) noises only when accelerating and definitely near the back end. It’s variable on RPM and either I can’t hear it or it goes away in higher gears. Ideas? Thanks! jake

  239. diva_3181377 says:

    My 2000 z3 2.3 auto with Torsen LSD differential have clunk when reversing the direction of rotation (like D-N-R or R-N-D) or sudden full throttle or when coasting to stop and then transmission engages. Also have noise which changes with slight change in throttle. If i let the wheels hang (in jack stands) and try it, no clunk. On Ramp, yes it is. There is no rotational looseness in the differential (as soon as i move the pinion end, it turns the CV shafts). I tried checking the carrier bearings on each side and drive side, seems to have some looseness and the clunk is coming from there.
    Driver side – https://www.youtube.com/watch?v=QNehmQeV89M
    Passenger side – https://www.youtube.com/watch?v=JTwLyVfqcM4
    Sound – https://www.youtube.com/watch?v=YEkdTYfgwRE

    Planning to open it up and check the carrier bearings. Can a carrier bearing cause a bad noise like this? Like clunk and whirr noise on acceleration ?

    Thanks..

  240. jason says:

    Hi tech guy, I’m just wondering if you could please help me out, I have a 2004 Nissan patrol automatic 4.8ltr petrol patrol, As you are probably aware they have very good lsd diffs in them, to the point where they are pretty much a locker. Wile turning from standstill and taking off the diff clunks once or twice at times, but when in 4WD and the tyres down on take off it really clunks and clunks like really loud, (when the steering wheel is not straight and I’m turning slowly) But then once warmed up it’s not so bad. I’m being told by everyone that it’s normal because of how well the diff is (LSD) but I’m not convinced? Also at around 60km/h a slight whine comes through the car only on really light acceleration then it drives out of it? These few things have me stuffed and no one really knows what it is or is willing to help or find out!! Please any advise or info would be great, also the car is always serviced, in excellent condition, low km’s wheel bearings are good and greased etc, I make sure everything is always 100%

    please help!

    thanks heaps

    Jason

  241. Tech Guy says:

    Hey Jake,
    ​​​​First, check your brakes (could be dragging) and your wheel bearings. ​Sounds coming from the ​rear end on acceleration could be due to ​worn carrier bearings or pinion bearings. Open it up, inspect the parts and change if needed. Also to reduce wear and tear on the new components you might install, you can use a lubricant together with the fresh oil you will add. One good lubricant would be CleanBoost EMT Engine and Metal Treatment. Read more about it here

  242. Tech Guy says:

    Hey Saneesh,
    You should remove the differential cover/drain and inspect the carrier bearings on both sides. Be looking for excessive play, wear and missing individual bearings that may be present in the bottom of the housing.

  243. Tech Guy says:

    ​Hey Jason,
    Clunking and banging noises on the corners can be due to lack of sufficient posi-traction lubrication, broken spider gears, or worn posi-traction or limited-slip clutches. Broken spider gears, moreover, can also immobilize the differential and create a loud, crunching sound during final departure.
    If the rear differential noise is characterized by clunking every two or three feet, then there is a great chance that a broken ring gear is the problem with the section with the broken teeth banging or grinding as it tries to engage the pinion.
    ​Whine noise could come because of ​a rear pinion bearing​.​ The bearing wear is allowing the pinion to move​ just enough that it is trying to cut a new pattern on to the ring gear.​
    ​Besides opening it up and inspecting there’s nothing else you can do at the moment. Please do keep us posted on what you find!​

  244. Amir says:

    Hello

    I have a truck that when i pull my foot from accelerator at speed of 80~100 km/h, i hear a howling noise from gear carrier, can you tell me what causes this noise and what should i do to fix it.

    Thank you for your advice in advance.
    Amir

  245. Benjamin says:

    Hi Tech Guy, I had this clicking noise at my 2001 Daihatsu Terios rear seat and wondered what causes the clicking sound everytime I bumped to road humps and uneven pathways. This noise started when I’d my both front and rear shocks and struts replaced. I had the front oil shock while gas for rears’. Do they influenced to have caused the noise? I did a replacement to my both front and rear wheel bearings too, but the clicking sound is still there. What symptom could that be? Please help.

  246. jason says:

    Ok mate, I’ll let it go for a wile, as if I’m only driving on road like I am at the moment its fine, but I will mention it to the mechanics when I take it in for the next service, thank you so much for your response and will keep you posted once I get to the bottom of it!

  247. Edward Kuhlman says:

    Hi Tech Guy: I have a 1980 GMC Vandura 25 Conversion Camper Van with a 1/2 ton differential (supposed to be 3/4 ton, but its been replaced). Both wheel bearings wore grooves in the axle shafts, I replaced the driver’s side with an SKF Bearing Repair Kit, then a little later the px side with a National Bearing Repair Kit. After awhile the National wore a new groove; I replaced both axle shafts with new Dana shafts, but the bearings seemed ok so I left them in (there was no play up or down, back and forth after installation of the shafts). Added Walmart Super Tech 80W-90W gear oil, seems ok, but there is still the, like, “growling” sound, I think at all speeds, maybe less at faster speeds. What do you think? Thanks.

  248. We have a ’68 Jag XK-E that a T-5 tranny has been installed and rearend ration changed from 3.57 to 3.02 (I think) to reduce engine noise and give “longer legs” on trips. Rearend ratio change was made professionally but there is now a loud whine under load. Particularly around 72-73 mph. What information can I provide that would help you diagnose our problem? Video? Recording? Mechanical information as photo of Reagan gear with indicator fluid?

    Thanks for your help!

  249. Tech Guy says:

    Hi Richard, I would say that the professional installation had something go ‘south’ if you will. Meaning that in the setup, something changed enough either with pinion preload or side clearance on the ring gear that would introduce your loud whine under load. Leaning toward the pinion preload at this point. If you have a Go Pro or similar video camera and the proper mounting clamp for it… a video would be helpful of course. Thank you and please keep us posted.

  250. SAMYAPPAN says:

    Tech Guy – Your feed backs are impressive and highly useful !

  251. Simon says:

    Hello Tech Guy,

    My machine makes a whining noise when stationary but turning the wheels from lock to lock? The noise only comes when almost at full lock and when crossing the centre position. So if I steer left and right at the point of the noise it squeaks like a wiper on a dry windscreen ???

  252. Ernest Kelebe says:

    hi, i have a hilux 1rz it had a diff noise. i gave it some people to repair. know it has change the speed. what could had happened?

  253. Bobby says:

    I have a 95 f150 4×4 and I hear a constant squealing sound coming from the rear. I pulled the drum off and checked the brakes and they are good, but it looks like there is differential fluid inside the drum. What exactly could be the problemishes? Bearings or seals?

  254. Tech Guy says:

    Hey Sam,
    Thank you for the kind words! Happy that we can provide quality help!

  255. Gus says:

    Hello, I have a 2007 Ford Sport Track 4×4 with 135,000 miles. It has a whining/Humming noise coming from the back, more noticeable at 35 mph and gets louder the faster you go. I put it in neutral to coast and the noise continues. I had the rear end oil changed and the tires rotated and it did nothing for the noise. Any suggestions?

  256. Tech Guy says:

    ​If you notice that the howling noise only occurs during deceleration, then it is a good indicator that the pinion-bearing preload has loosened.​ However if howling noises appear on acceleration also, this is an indicator that your gears have excessive wear, or are out of alignment (or depth) with each other. Good luck and keep us posted.

  257. Tech Guy says:

    ​As it sounds… it might be that your shocks and/ or struts fasteners are not properly torqued, or one of them is faulty. You should re-check these to be sure and if that doesn’t help, let us know.

  258. Tech Guy says:

    Be sure to check your carrier bearings as well. Thanks and good luck.

  259. Tech Guy says:

    Hello,

    As it sounds it might be your hydraulic power steering that requires a fluid change or check the drive belt for wear and or proper tightening. Finally, check the drive pulley on the power steering pump for wear and replace if necessary. ​Please keep us posted.

  260. Tech Guy says:

    Hey Ernest, we may need some better detail to help determine the cause.

  261. Tech Guy says:

    Hey Bobby,
    Great that you checked your brakes. You should get a look at your bearings and seals also since they both might need change. Once your seals (and possibly wheel bearings are replaced), and to reduce wear and tear on the new components you install, you can use a metal treatment lubricant together with the fresh oil you will add. One good lubricant (and forgive my shameless plug) would be CleanBoost EMT Engine and Metal Treatment. Read more about it here: https://boostperformanceproducts.com/emt-metal-treatment/15-cleanboost-emt-engine-metal-treatment-8oz

  262. Tech Guy says:

    Hey Gus,
    I’d suggest that you take a look at your pinion bearing and carrier bearings. The sounds that appear over 20 mph on either acceleration or deceleration might come from worn carrier bearings or worn out pinion bearings.
    Another giveaway of pinion bearing problems is if the sound is more like a whirring noise because it turns several times faster than the carrier assembly. Please keep us updated, curious to discover what the problem is!

  263. Peggy Robinson says:

    When the original owner of our 2005 GMC Savana 3500 had the van, he asked the dealer why the vehicle whined loudly on taking off, they told him that the manufacturer said it was supposed to sound that way. To me if there was anything wrong with the van you would not be able to hear it on take off. Our rear end diff locked up, when my husband was on the way home from Tx. It is a 3.73 with a 9.75 ring gear diff. Would we have been able to hear any indication of it going out with all the high whining it did since the day it was purchased? My husband is usually very attentive to sounds and notices if something is wrong.

  264. Alfred says:

    Dear Tech Guy,
    My Yutong coach bus was driven to a garage fix leak oil leak on rear differential. The mechanic called me that after finishing the works, he started hearing noises under the bus when they reversed the bus. On opening the diffrerential, it was heavily damaged with broken teeth.
    I suspect poor workmanship is the cause but mechanic is trying to hide their negligence by saying that it was brought in like that. I need your analysis.

  265. Tech Guy says:

    Hello Peggy,
    As it seems your hunch was correct. The high pitched whining noise could have been an indicator of low ​gear oil and/or some accelerated bearing/gear wear which needed to be taken care of.
    Due to poor lubrication, friction between components ​can cause overheating that ​very well could have ​lead to your rear diff to lock up.
    You should take it to a shop and have it opened up to ​assess ​the ​damage.
    Please keep us posted.

  266. Tech Guy says:

    Hey Alfred,
    If you drove the bus a lot with a leaking rear ​diff it’s very possible that the ​ring and pinion gears experienced lack of lubrication which leads to premature wear.
    Also lack of lubrication in the ​rear diff can lead to excessive heat ​and friction to where​ components might suffer heavy damage such as broken teeth.
    ​It’s hard to say whether or not the shop is at fault here.

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