All grease is made up of three basic components: lubricating oil, thickeners and additives. The National Lubricating Grease Institute (NLGI) assigns grades that describe the thickness of the grease. The NLGI grade is an industry accepted grade, and many fleet managers consider the NLGI grade as the primary indication of “good” grease. The mix of thickeners to the base oil is the most common differentiator among grades.
Trucks operate in some of the worst environments imaginable – high temperatures, low temperatures, dirt, dust, snow, water, salt, and de-icing chemicals are common. These extreme conditions and corrosive elements can damage the mechanical linkages that control steering and other weight-bearing interfaces on heavy-duty haulers.
The grease used on fleet trucks needs to perform in these environments in order to protect the investment in the trucks and trailers used everyday. Without a grease that can hold up in the trucking environment, and without regular lubrication, a truck can begin to experience major maintenance issues within as little as 100,000 to 150,000 miles, or roughly one year of service.
In addition to repair costs, which can easily range from $1,000 - $2,000, downtime can cost a fleet from $500 to $1,250 in lost revenue every day a truck is being serviced. Some fleet managers might assume the best grease to use is the thickest grease that stays around for a long time, but there are several factors in choosing the right grease for fleet trucks.
Many fleet managers use a thick, NLGI #2 grease on their trucks because it’s thick and the belief is it lasts longer. Unfortunately, the standard lubrication process results in extra grease being pushed out of the interface seals, wasting grease and providing an opportunity for contaminants to stick. Eventually, as the grease evaporates and/or is consumed, these contaminants are drawn into the interface where they can damage wear components.
Other fleet managers use a fluid grease, NLGI grades #000 to #0 for chassis lubrication. I recommend fleet managers ensure the service and grease they use is NLGI certified for GC-LB as defined by ASTM 4950.
G-level greases are used for wheel bearings and come in three categories: GA, GB and GC, with GC being the highest grade. For chassis lubrication, L-level greases come in two categories: LA and LB, with LB being the higher performing category.
NLGI #00 EP (extreme pressure) lithium grease is a fluid grease that works very well for fleet applications. NLGI #00 EP Lithium grease is often recommended for use in commercial vehicles with automatic lubrication systems. It is known for great metal adherence, which provides excellent wear and corrosion protection and water washout resistance.
NLGI #00 grease provides excellent protection against water and corrosion, and is typically pumpable even in low temperature conditions. A fluid grease by definition, NLGI #00 grease contains more base oil and less thickeners than NLGI #2 grease, so there’s actually more protective lubricant, pound for pound, in a #00 grease than a thicker blend.
Heads up when choosing a lubricant, some greases are not pumpable by centralized grease systems in colder temperatures. Even though the grease may have an operational use temperature of -40C or colder, the cold temperature rating doesn’t mean the grease will flow through an automatic lubrication system at those temperatures. For example, some systems on the market are not able to move temperature compliant NLGI #2 grease at -15C.
However, NLGI #00 EP lithium grease has excellent flow characteristics and has been proven effective in providing a persistent and replenishable protective layer against dust, salt, water and other debris found commonly on the road. As always, talk with your lubricant provider about the application and expected temperature range to ensure the best fit.
Grease is a costly investment for your fleet, but a good quality grease is critical for maintaining wear components and reducing downtime. Choosing the right grease for the application, and pairing it with an automatic lubrication system, will help reduce repair costs and downtime while keeping your fleet up and running smoothly and profitably.