I just changed out the rear end fuid with some mobile one 75-90 synthetic. Here is the messed up part, from what I am understanding it takes four quarts to fill up. When I drained out the old stuff, letting it drip for 30 minutes or so, I measured what came out, and it was barely 2 and a half quarts. Is this normal ?

Yes that’s GMs bean counters cutting cost.

Remember not to overfill the rear end; for some reason, GM thought that too much fluid can blow out the rear axle seals. Mine was ship low also.

From what I understand it holds 4 quarts! That is what I put in, I can just feel the fluid with my finger. Is that the right level? Does anyone know the exact amount that is supposed to be in?

4 quarts is what it takes. You might see a little spill over but 4 quarts is the correct amount.

GM changed the level in 04 sometime

There's a service notice about it here somewhere that I think Dmaxallitech posted

Don't know if they changed it to be cheap or for the axle seal as stated by Summitmaxlly.

I don't know how it could be for the seals when there’s a vent on the axle. I've got the impression form the guys on this site most of them fill it up all of the way.

Ya I agree, and I fill mine up to the bottom of the fill hole, but I think they changed it to be cheap so people would stop complaining about low levels from the factory.

my helms manual says 3.17 quarts for rear? mine is 3/04 build date. also front has white vent cap. helms says 1.83 quarts for front.

My Helms 2002 states 3.83 qts for the 11.5" rear axle.
The front 9.25" axle is 1.83 qts.

Talked to the guys at NAPA they looked it up it's 3.83 Qts.

Please let me VENT!!!!!

I'm reading the posts on DP reference the rear axle fluid not being full from the factory, So I decide to check mine before I venture off on my camping trip to Yosemite pulling my 7000lb TT. I get my 15mm socket to loosen the fill plug, I couldn't believe how loose the plug was, I coulda loosen'd it by hand....That's pretty SAD!! Then I stick my pinky finger in the hole.... Guess what?? I didn't get any fluid on my finger and half of my finger was down in the hole.. that's pretty SAD too!! People wonder why GM is in the mess they're in, Can't believe there is no quality control at the dealerships for the PDI.

Wife says take it to the dealer and have them fill it... Nope, I'll do it myself, this way I'll :grd: right!! I've only got 3000 miles on the truck, guess I'll do my own maintenance on my truck. Thanks for letting me VENT.

I'm back, I changed the rear axle fluid, it sure was easier than I imagined, anyhow, less than 3 qts came out:mad: . I filled with Mobil 1 synthetic gear lube, 75-90. I was thrilled at how easy and inexpensive (compared to the dealer) to do. While I was under the truck, I drained the oil and replaced the oil filter (ac delco filter), I refilled with Delo 400 15-40. I was gonna change my spin-on trans filter, stealer wanted too much $ for the filter, I'll order 1 from our supporting vendors and change it if it gets here before we leave for our trip. At 3000 miles with fresh oil and rear axle oil, I'll feel more comfortable taking my camping trip to Yosemite. This DP is the BOMB!

Thanks to all for the great info and advice!