Yes, i agree, go to a pro differential shop that does these jobs as a main business, you`ll have far better luck getting it set up correctly the FIRST time. The stealerships are clueless..!!! They`re just a bunch of "bolt-on" experts these days. They`ll just keep bolting parts on until they find and fix the real problem, and chances are, you`ll have to take it back to them MANY times until YOU give up. Anyhow, i`m just guessing... you`re probably going to find that the pinion is not shimmed properly. When you get it checked out, and decide to have it fixed, i would spend the extra money on a tru-trac posi unit. They are bullet proof...! I`ve put in 3 of these units in 3 different hemi truck 9.25 rearends, all 3 are now well over 100,000 miles on the tru-trac units, and all 3 are still as quiet since the day i installed them...also using valvoline lubes too. Just do the proper maintainance with the lube change, never worry again. And the tru-trac`s DONT need friction modfiers either...! Ther are NO clutchs in them...!

 

While I agree that the TruTrac is a WHOLE LOT BETTER than the stock LSD, and is a quality product, I dunno if I'd say it's bulletproof. I've seen a few fail and they'll implode rather nicely when they do.
I've run Auburn LSDs in the past, never wore out a clutch pack yet but I really wanted to try a TruTrac for my 3rd Gen until I was advised by my rep where I purchase parts from that the TruTrac is only recommended and warranted for tires UP TO AND INCLUDING 32" in diameter. Since he knows I run 35s and have on all my trucks since the mid '90s he made mention of it.

I subsequently called Eaton (who owns Detroit) who confirmed that the unit is NOT recommended for tires 33" or over in diameter and any warranty when running on tires that exceed 32" would be null and void.

Just thought I'd make mention of this because the 20" stock wheels on 4th Gens are 33" and a lot of guys like to lift and go larger...

 

GREAT CALL HAMMER,
i hadnt really thought about the larger tire thing. And yes, ther ARE some failures out there with big huge tires with the tru trac. BUT, ya gotta admit, some of these guys that had them fail were pretty abusive to their trucks though. None of mine ever failed because i only run stock size tires and i dont beat on my trucks at all. But cudo`s brother, good catch, and i DOOOO agree...!!! Yes, auburn is some good stuff, i wouldnt hesitate using their products at all. Only reason i went with tru trac was because it was simple, effective, cheaper price, for my stock applications.

 

changed over to Mobil gear lube in my truck's rear diff at 12k miles.. changed it again at 28k, and just recently at 40kish. Each time the gear lube was as clear as the day I put it in. OEM 9.25 LSD, used 75w140 and a 4oz bottle of Mopar friction modifier. Not saying you didn't have a bad experience but I've done two service changes with mobil and there were no metal shavings or soot/shavings with the old lube.

More than likely at the end of the day oil is oil.

 

If you`re having that good of luck with mobil 1, GOOD, keep using it. I chose not to.

 

mobil 1 was always the oil other syns were measured against. just wondering if the quality has dropped since the merger between exxon and mobil?

 

yoooo skippy, i think you`re onto somethin there.(lol) My thoughts exactly...!
It use to be the best, (maybe MANY yrs ago) now its on the list of the worst to use.
Friend of mine tried it, had the same issues in his chevy truck that i did, in my dodge`s.
Yeah i`ll stick with valvoline, not to mention, support AMERICAN jobs doing so.

Mobil 1 / Mexico
Mexico / Mobil 1 same no matter how you look at it....ROFLMAO

 

same as optima battery made in mexico.
i switched from m1, using since 1984, to penzoil ultra in this truck. never occurred to me to check where its made, hopefully not on the same block as m1 !

 

I just switched to Valvoline5w20 Synthetic oil and well, that and we started using midgrade, since winter mileage goes down but with the new oil I notice a difference in the way in runs when you kick in in the butt. Like a frikken race car. Sounds better too. I think I am gonna go with all Valvoline. I like the 300000 mile warranty, I was gonna go with Pennzoil their warranty is 800000 miles but realistically the truck will be a pile of rust or in the scrap yard before I get close to 100000 miles LOL but just in case. So sorta got a lifetime warranty and the thing is I go to dealer with my 7 quarts of oil and filter pay them 12 bucks to change it and still come in under the price of using their conventional oil because I buy the oil on sale at one of the local auto parts places in Michigan and they never pull us at customs in for car parts, no money in that for them.