Industrial Lubricants

Synthetic Main Bearing Grease

AMSOIL GMB grease is engineered specifically for use in wind turbine main bearings. Its unique combination of synthetic PAO base oils, lithium complex thickeners, and carefully chosen additives specifically solve common main bearing issues such as wear, rust, and grease deterioration or hardening. AMSOIL GMB grease works exceptionally well in large slow-speed bearings with high loads and in the moisture-laden environments that wind turbine main bearings are subjected to. AMSOIL GMB allows bearings to run freely with an ultra-low starting and running torque, yet they provide excellent wear protection and cause less drag than competitive products. AMSOIL GMB grease can be used in other applications and is an excellent choice for Yaw and Pitch bearings.

Typical Tecnical Properties

NLGI Grade 1.5
Thickener Type Lithium Complex
Color, Visual Tan
Penetration, Worked, 25°C, mm (ASTM D 217) 309
Dropping Point, °C, cSt (ASTM D 445) 278
Viscosity of Base Oil @ 40°C, cSt (ASTM D 445) 460
Viscosity Index (ASTM D2270) 181
4-Ball EP Test, Weld Load, kgf (ASTM D 2596) 250
4-Ball Wear @ 60C, Scar Diameter, mm (ASTM D 2266) 0.42
Water Washout @ 60C, %wt, (ASTM D 1264) 2.13
Emcor Test with 1% NaCl Solution, Rating (ASTM D 6138) 0/0
Corrosion Protection, Rating (ASTM D 1743) Pass
Fretting Wear, wt. Loss, mg (ASTM D 4170) 2.6


For recommendations on safe handling and use of these products, please refer to the Safety Data Sheet (SDS). Contact the AMSOIL Wind Group for more information.

WARNING: This product can expose you to Methanol, which is known to the State of California to cause birth defects or other reproductive harm. For more information go to