I finally understand automotive grease! Mostly. I think. Ya see, it breaks down like this: "Moly" is good for metal on metal where it doesn't spin fast, but has high pressure. Like knuckles, tie rod ends, and slip yokes. Its usually black.

"All purpose" grease is good for areas where you've got bearings that spin around. Less pressure, thinner grease gets into the nooks n crannies better. Also, in bearings, it has been said that a bunch of Moly can make the rollers/needles skid and scoot instead of roll, which could actually shorten the life of the bearing, whereas multi-purpose won't have that effect. Also multi-purpose grease is cheaper. Why not save a little, eh? Good for wheel bearings, u-joints and such.

You don't want to mix grease types. ie: Lithium shouldn't be mixed with aluminum based greases as they can break each other down and you end up with oily goo that slips out and doesn't lubricate correctly.

When all is said and done, most parts that want one type of grease will probably function just fine with the other type of grease, but just won't last as long (ie: 20,000 miles instead of 30,000 miles, or something like that).

So there you go. An overly simple explanation of when to use one vs. the other on automotive applications. Hint: mostly you can just look at the owner's manual, it'll tell ya what you need to know on these points!

Labels: landcruiser