Rear axel oil changes

[V8 Killer]

My ownsers manual says to do this every 24,000 miles .But it also always says if used under "severe Service".What exactly is that? Driving fast or things like towing? I bought the car with like 88 K and I really doubt it has been changed.

[TheGreenPunisher]

That would be things like driving in mountainous conditions continuously, or driving while in too low of a gear for long periods of time. Towing would fall under that also...

[Muttled]

How difficult is it to change that oil? I think my gaskets may be slightly leaking back there.

[Wozzeck]

Pretty easy. You need a gasket, and 2 qts. of gear oil. I use 75w-90. You'll also need GM limited slip additive if you have an LSD. Unbolt the 10 bolts that hold the cover on, and use a putty knife to gentyle break the old seal so that the oil will drain. Takes about 10 min to drain. Pull the cover off, and scrape away all of the old gasket. When you put it back together, it wouldn't hurt to put a little silicone on the cover itself and the pumpkin to help seal. Bolt it back down to about 15 ft/lbs in a criss-cross pattern. Unscrew the fill plug on the front of the pumpkin with a 3/8 ratchet. Fill it up to the bottom of the hole with the LSD additive and gear oil. Put the plug back in tight.

[TheV6Bird]

Originally posted by Wozzeck:
Pretty easy. You need a gasket, and 2 qts. of gear oil. I use 75w-90. You'll also need GM limited slip additive if you have an LSD. Unbolt the 10 bolts that hold the cover on, and use a putty knife to gentyle break the old seal so that the oil will drain. Takes about 10 min to drain. Pull the cover off, and scrape away all of the old gasket. When you put it back together, it wouldn't hurt to put a little silicone on the cover itself and the pumpkin to help seal. Bolt it back down to about 15 ft/lbs in a criss-cross pattern. Unscrew the fill plug on the front of the pumpkin with a 3/8 ratchet. Fill it up to the bottom of the hole with the LSD additive and gear oil. Put the plug back in tight.

It should be noted that filling up the diff is the hardest part, since the angle that the hole is on makes it tough to dump fluid in.

Jack up the car by the rear of the frame (not the axle itself) and let the axle hang, thus giving you more room. I used a funnel with a flexible plastic tube to dump the fluid in. Think of it as a college beer funnel: fill up the funnel with fluid, then raise it high and put the end of the tube in the hole and let the fluid flow into the hole.

[black98V6]

or you can buy a small hand pump at the parts store and use that, also comes in handy for tranny fluid changes on a manual trans