GOOD GREASE vs. BAD GREASE

— Tech tips on what you need to know for your CV joints,

as explained by Boss McKannick:

Dear Boss,
I just finished repacking the CV joints of my car, and I wanted to use the leftover CV joint grease in my RZR’s CV joints and wheel bearings. I was told by a counter guy at AutoZone that CV grease is no good for wheel bearings. I don’t really believe that, so I decided to ask you for the straight skinny on CV joint grease.

Danny Finn
Utica, NY

Actually, Danny, your AutoZone counter guy is correct! The average ball or roller wheel bearing is adequately lubricated with an NLGI (National Lubricating Grease Institute) Grade 2 multi-purpose or EP grease meeting NLGI Service Category GC for mild to severe duty. CV joint grease is often manufactured to NLGI Grade 1 and would therefore not be suitable for ball or roller wheel bearings. Grease is essentially an oil-delivery system. It is the oil contained in the suspension grease that provides the lubrication. A good grease is about 60 percent lubricating oil. This lubricating oil is drawn out of the grease by friction-induced heat. The grease is considered spent when the lubricating oil content is reduced to 50 percent. Grade 1 grease has the consistency of tomato paste and would be too thin for wheel bearing use. Grade 2 has the consistency of peanut butter and is what most people consider “normal grease.” Also, never mix grease brands or types. This may cause the grease to either harden or turn into a liquid, such as “de-gel.” Neither states are conducive to preventing metal-to-metal contact. For more information on greases, see the Amsoil site here: www.amsoil.com/newsstand/auto- and-light-truck/articles/a-closer-look- at-grease/.

Got a problem with your ATV or UTV? Send your questions to Boss McKannick at Dirt Wheels “Dialed In,” P.O. Box 957, Valencia, CA 91380-9057. Our e-mail address is [email protected], and include your name, city and state address.