Lubricant greases are semisolid products that have high initial viscosity commonly applied in wheel bearings and constant velocity joints. They are made from emulsified soap with oil and provide parts with what is called “thixotropy”. Thixotropy is defined as the shear-thinning property of “flowing” usually thick or viscous fluids through stress.
In vehicle applications, EP2 greases are applied on parts that cannot be frequently lubricated. It is also used on parts where lubricating oil usually doesn’t stay in position. In addition to this, EP2 grease can also act as a sealant that prevents ingress of incompressible components and water.
What is EP2 Grease ?
One type of lubricant grease used in automobiles is EP2 lithium grease. What is it ? It is a general purpose lithium-soap thickened grease for extreme pressures. Here, soaps disperse and viscosify oil to create the stable gels of greases. Lithium greases are non-corrosive and adhere very well to metal. They are also particularly great with heavy loads and have good temperature tolerances.
The said, properties are what makes EP2 grease popular for household products and automotive parts (e.g. CV joints, u-joints, ball joints, etc.) usage. Some formulations of this grease type include other substances like PTFE and molybdenum disulfide.
The presence of a lithium thickener in this type of grease increases operating stability range. Lithium’s good capability of coping stresses, also makes this grease type outstanding in managing a shift from low to high temperature.
EP2 lithium grease is best used for applications that involve a wide range of temperatures and high/extreme pressure conditions. This type has a higher melting point (around 500°F or 260°C or more) as compared to conventional lithium greases. This quality makes perfect for applications that involves heavier stresses and loads.
This type of grease also aids demanding applications by preventing leakage and meltdown. These properties make it great for high stress applications common in trucks. It is also great for the wheel bearings of conventional and disc brakes where conventional grease can and will usually melt. Below are other common applications where EP2 lithium grease can be used:
- Disc brakes
- Wheel bearings
- Ball Joints
EP2 grease is very popular for its versatility. The flexibility of its thickeners can be applied to a broad range of applications. In fact, despite it being more expensive, it is more advisable to use than other types of greases because it offers more advantages and has more uses. When choosing an EP2 grease, it is a must to consider an application’s operating temperature.
EP2 grease lubricants, moreover, also have better mechanical stability or shear stability than other grease types. It has good resistance against shear and breakdown because of its ability to remain its designed consistency and thickness (or viscosity) even when exposed to high mechanical shear forces.
There are basically two types of lithium greases one can choose from. The first are lithium complex greases and the second are simple lithium soap greases. The former are commonly used for general lubricating purposes while the latter are for more specific uses.
Generally, however, lithium complex greases are considered better choices because they have better dropping points, mechanical stability, water resistance, and oil separation resistance.
In “What is EP2 Grease – Part 2” of this article, we will tackle these said factors more comprehensively.