rear axle help
 

I am new to this Chevy forum and so far It's sweet! I have a problem and I need a solution. I want to change the rear axle fluid but not sure what type of fluid to buy and how exactly do I proceed with changing it? Also what type of gasket to replace it with. Please help me. :chevy:

Re: rear axle help
 

Hey welcome to the best boards around from MT glad you like it here :D What kind of truck do you have is it posi or just a limited slip setup? If its posi you will need to buy an additive for it. If not you just need a couple quarts of 80-90wt gear oil for it atleast 3 if I remember correctly. Pull all your diff bolts out and pry the cover off. Scrape all the old gasket off and take brake cleaner or the like and spray your rear diff out real good. You can buy a gasket or just use silicone gasket maker on it. There should be a check plug that you put a ratchet in and undo to fill it back up and check it to make sure its full. Then your good to go.

Re: rear axle help
 

Just did my 12 bolt in my 79 Big Ten. The fill plug is on the driverside front of the diff. I sprayed the fill plug and the 12 bolts with liquid wrench a number of times before I put a wrench on them, and had no issues even though everything was rusted up. Got a felt gasket from auto store and scraped old one off. Used a pad disk on a drill to get some of it off.

Cleaned up the inside with brake cleaner, wiped down where the gasket goes, put gasket on, bolted her back up -not too tight as you don't want to pinch gasket, maybe a quarter turn at most when you feel resistance on wrench. Add differential fluid until it spills out of fill hole, put plug back in and your good to go.

I used about a quart and three quarters and bought the kind with the additive in case I had limited slip as you can put it in an open diff. with no problems. Found out mine was open. Check for leaks over next couple of days. If leaking torque bolts around leak a bit more.

Re: rear axle help
 

Awesome thank you! I'm going to get started on it some time this week. Its a 305cu def not posi so im guessing it has limited slip. you guys are the best!

Re: rear axle help
 

"Posi" (Posi-traction) is just GM's trademarked name for a clutch-type limited slip differential.....

Same thing, different name.

Re: rear axle help
 

Welcome to the forum Bluebomb85...:)