"When basics aren't followed, it's going to cause reduced life," says Dan Arcy, Shell OEM technical manager. For instance, too much grease can be just as bad as not enough. As an example, overgreasing a U-joint can cause O-ring damage, and cause just as many problems as not having enough grease, he says.
"It's quite common that bearings get overlubricated, say on a trailer," Arcy says. "Too much grease is put in, the bearings aren't torqued down to the correct tightness, and those things can all compromise the life of the component." Too much grease, he says, can trap heat. "Typically your component manufacturer will have a certain amount of grease they want in the bearing - and most of the time, that's not packing the things as full as you possibly can."
Kirk Altrichter, vice president of maintenance for Washington-based Gordon Trucking, has an extensive training program for his technicians, and grease is one part of it. "We have a mockup slack adjuster on a stand to show examples of over greasing and under greasing," he says. "We can clean it out pretty quickly and have a go at it again."
Overgreasing is especially common on fifth wheel top plates. That extra grease just goes all over the frame, the shop, the yard, and the road.
"I know techs like to put that Zorro ribbon of grease on there because it's faster, and they think the trailer is going to do the rest of the job, but that's not the best way to do it," says Mark Betner, Citgo heavy-duty lubricants manager.
Altrichter developed a six-page slide presentation to educate his technicians on the proper way to apply grease to the fifth wheel.
"One of the things we've done is to get away from using so much grease on the fifth wheel," he says. "As soon as you hook to a trailer, it just pushes it off the fifth wheel onto the drivetrain or the ground. We went to just applying it to the lower third of the fifth wheel, so it then pushes it across the rest of the fifth wheel" when coupling the trailer. "We use a trowel to spread it, like you're putting glue on the back of tile. We're not tracking grease through the building, nor are we wasting as much grease."
Another area of concern is proper storage of grease canisters. "Grease is to be stored upright, not lying flat," explains Chuck Hamilton, technical service specialist for CHS, which makes Cenex brand lubricants. If they are stored lying on their side, air pockets can be introduced into the grease gun. This may be the problem if you think the grease tube wasn't filled right.