Okay folks, here is the deal.

I went to the *********** for a few filters and asked about my diff oil.

It turns out that they recommend special mopar gear oil for mt AAM 11.5 LSD which it is 24.50 a quart (which I'll need a gallon of)


AFAIK, a Torsen type LSD does not need any special type of oil, but now I'm cornfused.

Any advice?

 

Been running LE 607 in mine for almost 200k miles now... no issues !! Nobody buys stuff at the DEALER anymore... do they??

 

Mobil 1 or Valvoline 75w90. is about $11-12 a quart at an auto parts store. That's what I use.

 

I've used Royal Purple and Mobil 1 75w-90 in my GM 2500HD (same 11.5" AAM axle) and also in my Dodge. Currently have RP in my truck.

Both are available for about $10-11 per qt. I've got about 100k combined miles on either brand. No issues at all.

No friction modifier needed.

 

Any synthetic GL-5 rated gear oil in 75w90 is fine. I use Mobil 1, usually bought at GettoZone for under $10 a quart.

..

 

I have a torsen in the front axle of one of my Jeeps, but have always used just regular gear oil. The parts guy looked it up on his computer and they recommended their gear oil with what I'm guessing is a friction modifier, hence the question.

I didn't know that St-eal-er-ship was a bad word that has to be blocked

John

 

Spec in the book is full synthetic 75W-90 that meets GL-5.

I've run Redline in this and my last truck with no problems. I spoke to one of their engineers about whether I should buy the regular stuff, or the special stuff with no limited slip additive.

He basically said that the limited slip design in AAM's does not require limited slip, but the additive actually makes things slicker and would reduce temps in the contact areas of the ring and pinion, and wouldn't harm the limited slip.

I've found the limited slip works fine.

Of note, when you do it, there is an "Oil Level ----" stamped on the rear cover about 3/4" below the fill plug. Apparently they will blow axle seals if overfilled, and the stamping is easy to miss if you don't know it is there.

Also, if I recall correctly the book spec is 30 ft/lbs cover bolts and 24 fill plug. Lots of people have broken bolts before they reach 30 ft lbs, so I'd recommend not torquing them quite that high.

 

I used Walmart gear oil. Works fine...

 

I was surprised to find the cover blots loctited and felt like they had been driven on with an impact wrench when I pulled the covers off the 2007 to change diff fluids.

Needless to say I put them back on with a little less torque. Gotta love those reuseable gaskets, tho...