Differential oil for rear diff. 2003 gmc 1500hd

[Bud1952]

What type gear oil goes in rear differential on 20p3 1500 hd truck?

[Mr. Z71]

This is from a 2003 GMC Sierra owner's manual... "SAE 75W-90 Synthetic Axle Lubricant (GM Part No. U.S. 12378261, in Canada 10953455) or equivalent meeting GM Specification 9986115."

 

I can't see an HD requiring something different, anyone else care to comment?

[Logan Lanfear]

It would depend more if it was a limited slip or not.  If its a G80 it might require limited slip oil.  If not, whatever brand you prefer filled until it comes back out the hole.  

[redwngr]

The current recommendation for the HD is the same as posted above:

SAE 75W-90 Synthetic Axle Lubricant (GM Part No. 88900401, in Canada 89021678). 

 

G80 was probably standard on the HD's.  It is today.  No reason not to use the same fluid anyway.

 

The 1500's get the synthetic 75w-90 in front, synthetic 75w-85 in the rear