Where can I find "moly fluid" to add to the differential?

I'm trying to troubleshoot a rumble on my '89 Laredo that happens after 55 mph.

In my search it's been recommended to add "moly fluid" to the differential...if the "moly fuild" quiets down the rumble than something in the differential needs to be looked at.

But I've been to a few places and no one has it or as heard of it. Is there a brand name I need to buy or is 'moly fuild" generic?

Thanks!

Lubro is the brand I've seen.
Moly is generic for Molybdenum

Limited slip additive is also another term. Trans X makes some, NAPA sells it, can't think of the name right off the top off my head, but it runs about $9 a tube, and contains moly b.

The only additive that should be required for your differential is "limited slip friction modifier" - and that only if you actually have a limited slip (like Dana Trac-Lock.) There should have been a tag on one of the cover bolts saying "Use Limited Slip Diff Lube Only," or somesuch.

It won't hurt if it's added to gear oil that doesn't go into an LSD axle, but you're right - if it quiets things, you've got bigger problems. Limited Slips without LSD/FM usually "chatter" - that's the clutches sticking without the friction modifier. If it's been going on for too long, you're probably looking at replacing the clutch packs (an involved job, but it should not be terribly difficult elsewise.) Clutch packs without LSD/FM too long get wrecked, and can't be saved.

LSD/FM should be available at any well-stocked parts house. Most axles call for the addition of two ounces to capacity (which is what, a quart or so?) I've got an 89 w/factory LSD, and I've just been adding 8 ounces to a gallong of gear oil, so I don't forget (like I said, it won't harm anything if it's not needed, I just can't be arsed keeping track of lube for just one axle out of eight...)

5-90

Would have to agree on never hearing about moly fluid...however I used to work for Nissan and the latest models coming out have molybdenum rods and cranks even the little sentra..haha. Apparently it is a stronger, shinier, slicker, finer metal that they make them from. I would assume that this moly lube or fluid has some kinda aspects of the metal itself to either help with stand the friction or merge into the existing type of metal on the rods and give it a type of lubrication for less of a word to use. But yeah I wouldn't expect anything that is hard to find to be cheap or for that matter be THAT big a benefit. I agree with you on if there's a rumble it needs looked at and I don't think any plain fliud will squelch a rumble. If you find some and try it please inform us of the results, I'd like to know if it has any pluses. Thanks.

Go to a disco biscuits show....




(im 99% sure no-one on this board will get that^^^)

mtnxj said:

Limited slip additive is also another term. Trans X makes some, NAPA sells it, can't think of the name right off the top off my head, but it runs about $9 a tube, and contains moly b.

Click to expand...

Limited slip additive is not moly. In fact, the best moly gear lube additives are not recommended for limited slips, or automatic transmissions.

I get my moly additives from Mr. Moly (http://www.mrmoly.com/). They specifically tell you NOT to run the gear lube additive in limited slips, but you can run the automatic tranny additive in limited slip diffs.

As for whether or not moly additive is beneficial -- I have 254,000+ miles on the Peugeot 5-speed tranny in my '88 Cherokee and it still doesn't whine, grind, or make any strange noises. I think the stuff is worth whatever it costs, and I use it regularly.