Rear diff fluid

[GRTWHT1]

What is the reccomended fluid for our rear diff's
I've got some royal purple 75w 140 left over from another project and was hoping to be able to use it here also.

[Easy Ed]

2003 Owners Manual shows for the front and rear diff.

SAE 75W-90 Synthetic
Axle Lubricant
(GM Part No. U.S. 12378261,
in Canada 10953455) or equivalent
meeting GM Specifications 9986115

[GRTWHT1]

Thanks Ed, the 75w 140 was in my f-350

[Luv2Camp]

Just know that, to my knowledge, there is NO 75-90 gear oil out there that meets GM specs listed in the manual. GM also makes their fluid smell like grapes (I am NOT kidding) This is an easy way for them to tell when they drain the fluid if it is genuine GM fluid or not just by the smell test! The stuff is not cheap either..

[HumminNBoatin']

I replaced my front diff fluid with 75-90. Should not be that hard to find and do. In fact the diffs in the H2 don't even need any special additives as they do not have LSD's.

[Easy Ed]

Drained and refilled both diffs 3/27/05 at 29,795 miles with Mobile Synthetic Gear Lube LS 75W-90 and now have 86,624 miles on it and have no probs..... so far. Front diff does have slow leak and when I do the oil changes, I just top it off if required.