Exactly... even then you don't have to take it!

 

Heck the dealers around here don't use Mopar gear oil.They use stuff supplied by BG ! I'd sure like to see that TSB saying 80w140 in the AAM 11.5 differantial.Been hearing about it for years but no one has ever come up with it on paper.Service manual calls for 80w90!

 

From my manual. 11 1/2 AA - MoparT Synthetic Gear Lubricant 75W-90.
I have heard about using heavier oil ,but have not seen it in person.
Someone with a newer manual should have the updated information.

 

07 manual says same thing.

 

I wonder how long the rear end was ran low on oil. The '03's where know to come from the factory over a quart low and never checked. I had to put in 1.5 qts when I bought mine to bring it up to the level check plug.

MikeyB

 

With as many folks posting on numerous Dodge diesel sites that I read(some are the some folks of course) Using OTHER gear oils as well as some that buy factory stuff again.Theres very very seldom a differantial failure ever posted.Some don't service their diffs for 50k.I've had friends that tow witrh these trucks 90% of the time not service Diffs.until 100k for the FIRST time. I think something in this diff.just failed and gear oil had no affect on it.

 

Thats a good question. I bought the truck with 15,000 on it and had the dealership change the oil (and filters where applicable) for tranny, engine, t case, diffs (f and r) and the fuel filter, and do a radiator flush and fill as part of our purchasing agreement. (also establishes maintenance baseline for me) I trust that this dealer did all those things since they are a family friend and we have purchased many vehicles from them. So at most 15,000 miles low on lube, I've done everything since then.

 

The only thing I have ever seen from Dodge about using the heavier 75/140 gear oil was only for the 1/2 ton trucks with the smaller rear ends. I talked to Dodge back in Sept. they said 75/90 GL5 synthetic gear oil was the correct oil to use in the 10.5 and 11.5 rear ends.