Rear end Getting Pretty Hot. Need Help

[AMSOILGUY]

150 degrees is normal for diff temps. in my experience, ive seen many premature gear wear from synthetic gear oil. gear sets starting to make noise in under 15k miles. in my shop we use straight schaeffer's 209a 140 wt oil. its really sticky and we have never had a gear oil failure. lucas oil is what we will recommend if schaeffers is not available.

the puking out the vent us usually from the turns pushing all the oil into the tube. ive had some road race guys put vents in each tube then run hoses to the catch cans.

Was the fluid tested to determine it was the culprit in your past experiences?

[bryant]

no testing, but its pattern failures seen mostly in ford f150s and explorers. i first started see f150s that were making gear noise in under 15000 miles around 97 when ford went to synthetic oil. now i do realize that all company's oils are not the same. a few aftermarket limited slip manufactures even say not to use synthetic oil. i have seen amsoil used is diffs from other builders and see no problems with it. we have used schaeffers and had no oil related failures. it a bit over kill but thats what is needed to stand by our work.

[CTSV]

Where can i buy some Schaeferrs moly gear oil to try out?

[AMSOILGUY]

Where can i buy some Schaeferrs moly gear oil to try out?

You'll have to find a distributor in your area I believe. I would think that they would have a locator online.

If you have any interest in running AMSOIL here's a link to our gear lubes. AMSOIL Severe Gear Lube

[CTSV]

You'll have to find a distributor in your area I believe. I would think that they would have a locator online.

If you have any interest in running AMSOIL here's a link to our gear lubes. AMSOIL Severe Gear Lube

You do offer several but all are synthetic based and was specifically told by Strange and Moser not to run any synthetic in a Tru trac.

[AMSOILGUY]

You do offer several but all are synthetic based and was specifically told by Strange and Moser not to run any synthetic in a Tru trac.

I completely understand. Run what your comfortable with. If it were mine I would ask them for a spec and go from there. As Ron said earlier all synthetics are not created equal.

[Ron Sutton]

I completely understand. Run what your comfortable with. If it were mine I would ask them for a spec and go from there. As Ron said earlier all synthetics are not created equal.

They vary a lot. Sometimes they even vary from one type of lube to another within the same brand. There is a brand of synthetic oil I found from lots of testing & experience that has the best gear oil & the worst engine oil. I wouldn't run their engine oil when it was given to us for free, but I'll pay full price to run their gear oil.

It's important to understand "why" Eaton is saying not to run synthetic. It has nothing to do with heat or wear. It is simply that many brands of synthetic gear oil are so slippery (higher lubricity ... which is a great thing for everything else in the diff) that they make the clutch discs slip. So add a friction modifier "posi additive" and party on.

Thanks for the kind words Jimmy & Ramey.