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Maintenance Minute: Hey, What About the Fifth Wheel?
If you haven’t touched the fifth wheels on your fleet of vehicles, don’t feel bad. They are the most overlooked component on a truck. But you do need to pay them some attention by regularly removing the old grease that has accumulated dust and dirt. This results in a gritty surface that cuts a fifth’s wheel’s performance and life.
So, draw straws on the farm to see who gets to scrape all that old grease off. Then select the right grease for the job. You do not have to use two different greases for a truck’s chassis components and the fifth wheel, says Mark Betner of CITGO. “What works best to prevent water washout and premature grease displacement, especially on truck kingpins, is an NLGI #2 grease made with a heavier base and robust anti-corrosion and anti-wear additives system,” he recommends. “Greases made with at least an ISO 320 to 460 base viscosity grade tend to prevent water washout and pound-out in areas like the truck kingpins. However, keep in mind that heavier base oil greases can be more difficult to pump, which is why synthetic base oil greases can deliver both good pumpability and staying power while in service.”
With the right grease in hand, complete the job by applying a thin layer of grease starting at the lower end of the fifth wheel and applying grease approximately two-thirds of the way up the plate. Avoid putting on too much grease as it will end up on the ground or truck frame during engagement of the trailer. “Also, apply some grease down in the jaws and any grease fittings that a fifth-wheel manufacturer may have included for overall lubrication best practice,” Betner adds.