Rear differential service?
 

What's the factory recommended change interval for the rear AAM? What's the recommended weight of gear oil?

holds 3.83 quarts
Gear oil 75W-90 synthetic or equivalent.

only thing i can find for regular change interval is check the level every 5k and add if needed.

So the GM crowd doesn't have a ridiculous 15k change interval like the Dodge crowd?

We (Dodge guys) were discussing this the other day, and were curious as to the change interval for the GM folks since both use the AAM 11.50 rear axle. Dodge specifies 75w90 and 15k change intervals (front and rear if 4wd).

Seems funny that the same axle, under two different models, would specify completely different maintenance.

i could be wrong, i thought i seen it posted somewhere on the net the regular change interval.

i found the info skimming though my fsm

I garantee you I have 5 trucks with over 200k and at least 15 other trucks between 100-200k that have NEVER had the rear diff fluid changed AND do not have problems. :ok1:

Thanks for that info 2500.

Don't get me wrong, I have approaching 200k on my truck, and the fluid has only been drain two times (50k mobile 1, 75k royal purple). I disregarded the recommended 15k change interval because I thought it was excessive. My logic was the simple fact there is no significant differences between this differential and one built 25 years ago...they use similar gears, bearings, races, and seals. I'm not arguing the fact they won't go that many miles, only trying to determine WHY Dodge would specify a 15k change interval.

I would like to see if the GM Owner's manual has a change interval? Dodge has a standalone booklet for maintanence intervals.

Nope. '99 and up only says "check fluid level".

Cool, that's what I was looking for!

75W140 is recommended for towing IIRC

On DP there its recommended 100K change interval posted by a tech several years ago I'm not sure if that was GM or just a general recommendation made by him. Rttoy has plenty of Dmaxs in his fleet so I would trust him. 200K on that nasty break in oil....wow

break in oil is supposed to be swapped out at 500 miles