Mobil 28 Aviation Grease

Mobilgrease 28 is a high-performance synthetic aviation grease formulated with a polyalphaolefin (PAO) synthetic base fluid and an organo-clay, non-soap thickener. Its wide operating temperature range, low-temperature mobility, wear protection, corrosion resistance, and water-washout resistance make it a versatile choice for aircraft wheel bearings, landing gear, flight controls, actuators, airframe mechanisms, and other demanding aviation lubrication applications.

Mobilgrease 28 is qualified to MIL-PRF-81322G and is approved to NATO G-395. ExxonMobil identifies the grease for use in both multipurpose airframe and wheel-bearing applications, making it useful for operators seeking to consolidate aviation grease inventories.

Features and Benefits

• PAO synthetic base fluid provides excellent low-temperature mobility and thermal and oxidative stability.
• Organo-clay, non-soap thickener provides high-temperature stability and a wide operating range.
• Wide temperature performance from -65°F to 350°F (-54°C to 177°C), with appropriate relubrication intervals.
• Low starting and running torque supports operation in low-temperature environments.
• Wear and corrosion protection helps protect bearings, airframe mechanisms, and other lubricated components.
• Water-washout resistance helps maintain grease performance in adverse weather and water-exposure conditions.
• High load-carrying capability supports heavily loaded bearings and mechanisms.
• 10-year shelf life supports long-term aviation inventory management when stored properly and unopened.

Aircraft Applications

Mobilgrease 28 is designed for plain and rolling bearings operating at low to high speeds, as well as mechanisms requiring friction reduction, wear protection, and low lubricant friction losses.

• Aircraft wheel bearings and landing wheel assemblies
• Landing gear assemblies
• Flight control systems
• Control-system actuators
• Jack screws and screw-drive actuators
• Servo devices
• Splines and airframe mechanisms
• Oscillating bearings
• Sealed-bearing motors
• Helicopter rotor bearings

ExxonMobil also identifies Mobilgrease 28 for certain industrial and naval shipboard applications where extreme temperatures, high speeds, load carrying, or water resistance are important. Equipment manufacturer approval should always be verified before use in a specific application.

Specifications and Approvals

Mobilgrease 28 may also be encountered in maintenance documentation referencing superseded specifications including MIL-G-81322 (WP), MIL-G-7711A, MIL-G-3545B, and MIL-G-25760A. Always follow the aircraft, component, or equipment manufacturer's current maintenance documentation for the applicable grease specification.

Typical Product Properties

The values above are typical properties and are not product specifications. Refer to the current manufacturer documentation for applicable product specifications and acceptance requirements.

Storage and Shelf Life

Mobilgrease 28 has a 10-year shelf life when stored under appropriate conditions. ExxonMobil recommends storing aviation greases indoors in a clean, dry environment at normal storage temperatures of 32°F to 104°F (0°C to 40°C).

Once a grease container has been opened, the stated shelf-life recommendation no longer applies because exposure to contamination and environmental conditions can affect grease performance. Keep containers closed when not in use and follow the manufacturer's storage and handling recommendations.

Product Information

Frequently Asked Questions

What is Mobilgrease 28 used for?

Mobilgrease 28 is a multipurpose aviation grease used for aircraft wheel bearings, landing gear assemblies, flight controls, actuators, jack screws, splines, oscillating bearings, helicopter rotor bearings, and other airframe mechanisms where the aircraft manufacturer specifies an appropriate grease.

What specification does Mobilgrease 28 meet?

Mobilgrease 28 is qualified to MIL-PRF-81322G and is approved to NATO G-395 and MIL-PRF-24508B.

What is the temperature range of Mobilgrease 28?

ExxonMobil lists a recommended operating temperature range of -65°F to 350°F (-54°C to 177°C), with appropriate relubrication intervals.

Is Mobilgrease 28 suitable for aircraft wheel bearings?

Yes. ExxonMobil identifies Mobilgrease 28 as an approved multipurpose airframe and wheel-bearing grease. Always verify the applicable aircraft or component maintenance documentation before selecting a lubricant.

What is the shelf life of Mobilgrease 28?

Mobilgrease 28 has a 10-year shelf life when stored appropriately and unopened. Once the container is opened, the stated shelf-life recommendation no longer applies.

Can Mobilgrease 28 replace another aviation grease?

Do not substitute aviation greases solely based on viscosity, NLGI grade, or apparent similarity. Verify the aircraft, component, or equipment manufacturer's approved lubricant and specification before making a grease change.