Source: har-tech

What is Grease

For components that are lubricated with grease, grease quality and service intervals are very important. Sometimes, using grease with a particular Volvo part number is recommended. If this part number is used, you will automatically get the correct grease grade.

The type of grease that should be used depends on different characteristics, i.e.:

• Type of thickening agent
• Consistency of the grease
• The presence of EP additives
• Occurrence of solid lubricant

A lubricating grease consists of a solid or semisolid lubricant that contains a thickening agent (soap) added

to a liquid lubricant. Other normal additives are EP (Extreme Pressure) additives, corrosion inhibitors, etc. Normal thickeners that are used are so called sodium, calcium or lithium soaps, or corresponding complexes where the metal soap is compounded with a salt that is normally based on the same metal. These thickeners are called sodium complex, lithium complex, etc. and can generally withstand higher operational temperatures than the original substance.

The consistency (hardness) of a grease is given by an NLGI number, which can vary from 000 to 6. Grease with the lowest consistency (softest) has an NLGI #000 while the hardest grease has an NLGI #6. The greases that are often recommended by Volvo are based on lithium or lithium-complex with EP additives and NLGI #2 (NLGI #000 or #00 occur in central lubrication). Normal lubrication points for grease are the turntable, propeller shaft, wheel bearings, suspension, etc.