Rear diff fluid, plug and/or cover?

rjirvine · June 14, 2005

I need to change my rear differential fluid in my 2000 Silverado with 4.10 gearing, not a locker. Should I just use the drain plug, or should I remove the rear cover too? The truck has 92,000 miles on it and I got it about a month ago.

MS3DALE · June 14, 2005

I just used the drain plug on my '99,But it woundn't hurt to remove the cover and inspect everything and clean the magnet off.Thats what I have to do on my '04 now since they took the drain plug away

99silveradoz71 · June 15, 2005

I'd pop the cover and clean her up nicely. I did on mine early on.

MountaineerTom · June 15, 2005

I took the cover off of mine. It wasn't hard to do. This is what it looked like after 22,000 miles.

Close up of the magnet.

This is after I cleaned it.

rjirvine · June 16, 2005

I pulled the cover off and cleaned the magnet. It wasn't too difficult, but would have been easier if I had removed the spare tire (was feeling lazy). I got a new gasket from the dealer for $10.97 and 2 quarts of 75W-90 fluid for $26.24 each. I'm not sure if the fluid had ever been changed, but it was a medium honey color coming out. At least I have peace of mind now. I put about 2.2 quarts in and measured it with an allen wrench. I had to drain a little out. The placard calls for a depth of 15-40mm which equates to about .6 to 1.6 inches below the filler hole. I have it at about 1.0 inches. I drove it back and forth in the driveway and measured again, but it didn't need any more fluid.

The parts guy at the dealership said the p/n 26066456 gasket fits ALL 1/2 ton trucks (at least for the 2000 year).

I didn't use any permatex on the gasket because I don't think you have to, although I've used a little in the past on my 1988 truck because i had problems with leaks.

The cover bolts are 30ft-lbs and the drain/fill plugs are 24 ft-lbs per ALLDATA.com. They take a 3/8" drive to remove.

Thanks for the advice and pics!

2000 Silverado 4x4 ext cab, 5.3l, Z-71, 4.10 rear diff

BlueTahoe · June 16, 2005

I have looked at my rearend a few times

I can't seem to find a drain plug that is obvious. Do the tahoes not have a drain plug? I have a 2003 tahoe posi 3.73. I had all the stuff to change front and rear fluid but couldn't find the drain plug. Should I have a drain plug like the front or are you referring to Drain/Fill plug as 1 plug and you are using something to suck the fluid out the fill hole. I don't mind dropping the cover I just havn't bought a gasket yet. If I have to drop the cover. Is a parts store (autozone, o'reilly's) ok or should I go to the dealer?

Thanks!

rjirvine · June 16, 2005

I'm not sure if your diff has a drain AND a fill plug. Mine has one of each. The drain plug is at the bottom of the differential and is flush with the exception of the square hole for the 3/8" drive to remove it. You might have some mud or something hiding the hole, but it's pretty obvious. The magnet for mine is glued to the rear cover, and the drain plug ison mine is not magnetized. I got my gasket at the dealer only because I had to go there to get the fluid. I would assume one from autozone or any other car place would be fine. There was nothing special about it.

MS3DALE · June 16, 2005

I have looked at my rearend a few times

I can't seem to find a drain plug that is obvious. Do the tahoes not have a drain plug? I have a 2003 tahoe posi 3.73. I had all the stuff to change front and rear fluid but couldn't find the drain plug.

Sorry BlueTahoe,Your '03 does not have a drain plug (In the rear,the front still has one) GM took them out of the 1/2 tons in the '02 model year.

BlueTahoe · June 16, 2005

Hmm That stinks!

Guess I can just drop the cover then. Thanks!

Bish · June 16, 2005

Hmm That stinks!

Guess I can just drop the cover then. Thanks!

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Yes, it just makes it messier. I use a trick I learned on another board for the rear. I use gasket adhesive on the Diff side and put a thin coat of oil on the cover. The next time I pull the cover, I just rap it with a mallet and the cover falls off leaving the gasket firmly attached to the diff so it can be re-used and you don't have to scrape the old one off.

BTW- I refuse to pay GM $27 for a quart of their grape diff oil. I've been using Mobil 1 for 145K with some towing and it still looks nice and clean in there.