Mobilgrease 28

Mobilgrease 28

Mobilgrease 28 is a supreme performance, high temperature, anti-wear grease designed to combine the unique features of a polyalphaolefin (PAO) synthetic base fluid with an organo-clay (non-soap) thickener. The clay thickener provides excellent stability at high temperatures and Mobilgrease 28 has a high dropping point value of around 300C.The wax-free nature of the synthetic base fluid, together with its low coefficient of traction compares with mineral oils, provides excellent low temperature pumpability, very low starting and running torque, and reduced operating temperatures in the load zone of rolling element bearings. In addition it resists water washing, provides superior load-carrying ability, reduces frictional drag, and prevents excessive wear. Tests show that Mobilgrease 28 prevents friction oxidation (fretting) and effectively lubricates rolling element bearings under conditions of high speeds and temperatures. It has also shown superior ability to lubricate heavily loaded sliding mechanisms, such as wing flap screw jacks. Its consistency is between NLGI No.1 and No. 2 grease.

Advantages and Potential Benefits:

A particular need of aviation greases is the need to resist high temperature stresses, whole providing excellent starting and low torque at low temperature. To meet this combination of needs the ExxonMobil product formulation scientists chose proprietary synthetic base oils for Mobilgrease 28 because of their exceptional thermal/oxidative resistance potential, and superb low temperature capability.

Mobilgrease 28 meets the requirements of key military and commercial aviation specifications and has built up a superb reputation for performances and reliability among users around the world.

  1. High viscosity index base stock with no wax content ensures a very wide operating temperature range – outstanding high and low temperature performance and excellent film protection at high temperatures
  2. Low traction base oils leads to low sliding friction and reduced heat build-up and the potential for energy saving
  3. Excellent protection against fretting wear and corrosion providing superb bearing protection and extended bearing life and reduced bearing replacement costs
  4. Extreme-pressure characteristics, avoid excessive wear, even under shock loadHigh thermal/oxidative stability, extends re-lubrication intervals
  5. High resistance to water washout, maintains excellent grease performance in adverse weather and other water-exposure conditions


  1. Mobilgrease 28 is an approved against military specifications MIL-G-81322G for wide temperature range aviation service and meets the quality level DOD-G-24508A for shipboard service.
  2. Specific military and civil aviation applications include:

- Landing wheel assemblies

- Control systems, screw jacks, servo devices, actuators, sealed-bearing motors and oscillating bearings

- Helicopter rotor bearings on aircraft and naval shipboard auxiliary machinery

- Subject to equipment manufacturers approvals where superseded specifications MIL-G-81322 (WP), MIL-G-7711A, MIL-G3454B, and MIL-G-25760A may be called for.

Product Specifications

Has the following approvals:
MIL (US) MIL-PRF-81322G and NATO G-395
Recommended by ExxonMobil for use in applications requiring:
DOD-G-24508 A, Amendment 4

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