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.

[Luv2Camp]

Originally Posted by 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.

When my warranty is up and I change the fluid again, I will go with the Mobil BUT because even Mobil advises that there geral oil does not meet the GM specs, I am not risking a reason for Hummer to deny a warranty claim should I have a differential failure

[Easy Ed]

Understandable....

Originally Posted by Luv2Camp

When my warranty is up and I change the fluid again, I will go with the Mobil BUT because even Mobil advises that there geral oil does not meet the GM specs, I am not risking a reason for Hummer to deny a warranty claim should I have a differential failure

[GRTWHT1]

What does the manual spec for quantity in the rear diff ?

[Easy Ed]

Service Manual for 2003 shows the rear holding approx. 4.0 Pints/1.9 Liters

Just for the future, front holds approx. 2.6 Pints/0.8 Liters

Originally Posted by GRTWHT1

What does the manual spec for quantity in the rear diff ?

[HumminNBoatin']

I just fill it until it starts to come out of the fill hole.

[Easy Ed]

True, but how do you know how much to buy at the parts store if you are changing out the fluid with new

Originally Posted by HumminNBoatin'

I just fill it until it starts to come out of the fill hole.

[TXSUT]

Originally Posted by GRTWHT1

What does the manual spec for quantity in the rear diff ?

Just in case....PML shows that their H2 cover's capacity is 1/2-quart over the stock cover.

[GRTWHT1]

Thanks TXSUT I haven't been home long enough to even open the parts bag.
Figured I could poke around here and get some info.