Hey, if you havn't changed your rear diff fluid - just because most people simply forget to, or just don't know, until it's too late :sad: ...So being that I was bored again + we had a nice day and all , -- I decided to take on the small task myself. The car loves me for it !

Ingredients / tools needed:

- 1.69 Quarts of M1 Synthetic Gear Oil (GM equivalent 12378261) SEA 75W-90 (Z06 3.42's, other gears may vary slightly)
- 4 oz. of limited slip additive (EQUA TORQUE) or GM part #1052358
- A big 'ole Hex Key, like 1/4" I think it was ..
- Some rags and a fluid oil pump ($5 at pep boys, very useful)

Here they are:


Jack the car up or drive it on some ramps, so you can get under the rear axles. Then support it, so it doesn't kill you (:smash:). Next, find the drain plug on the bottom of the gear box, which there are two of, so don't get confused ... one is actually on the side, it's the FILL Plug !

Safey is first (:nopity)

I actually used ramps on the rear, but you get the picture, right !?

The one from the back, is the FILL (It has a little tag attached to it) pointing rearward and facing sideways.


Now, between the rear swaybar and leaf spring ... DO NOT GO TO YOUR TRANSMISSION, YOU'VE GONE TOO FAR.

This big thing is your tranmission (:D)


Ok ... so let it all drain.



At 18.5K miles, this is what the old gear lube looked like (Yikes!):


In my case, there were no significant "metal" particles or anything like that - but some have reported a couple of lose gears and ball bearings (just kidding) - in their gear box, especially all you 3.73 and 3.90/4.11 racers ! :lol:

Now ... retighten bottom plug to 26 lbs-ft. & pump in 1.69 (about 1 and 3/4, little less -- quarts of the new stuff - as such, using the pump.




In the process, you will add ANOTHER 4 ouches of limited slip diff fluid, to top it off until little begins to pour out, or to top of rear fill plug! Don't over fill it !
Retighten, this second bolt to 26 lb.ft - and drive normal, NO WOT - until 300 miles have passed. Send me email, if you got more questions. Total time to do this is approx 30-45 mins, if you're maticulous. Total cost was $30 vs. $140 @ dealer.

:flag

 

Thanks, thats great help!!! :cheers: :cheers:

 

nice writeup, I've done this one myself also, did the oil again yesterday :D

 

Nicely done. You should post that in Tech Tips. :cheers:

 

Thanks for the info!

 

Is that how you got so drunk? :lol:

 

Thanks for documenting this. I agree to post it in tech tips to make easier to find when we all get a round tuit.

:cheers:

 

Thanks for posting these tips. I've printed them and will use them when it's time to change the diff. fluid. :cheers:

 

nice work Bliss, now you need to document a head and cam instal :D

 

:cheers:

Nice job Rob, that should be worth 25 percentage points back at least.

 

I agree!

What did ya get docked for?

 

Good post. It's about time for me to do this. To be safe, make sure you can remove the fill plug before you drain it.

 

Good post/photos. If any of you are going to try this, be sure to : :smash: :)

 

Thanks BLISS, I'm one of those who forgot. Good explanation and pics. It looks like a very BLISSful experience. :yesnod:

 

Just did this myself the other day. The fluid pump is a HUGE help. Transmission is just as easy as the diff.

 

Great instructions! They are printing out right now. :cheers:

 

Wow, that was a great, detailed write-up.

I'm gonna do mine soon.

THanks again, great job!

 

Bliss-

Appreciate the tips.. Nice job.

How about the MN6 fluid procedure next? :D

 

Can someone please confirm the size of the Hex Key? Also do you need the Limited Slip additive for the Redline MN6 fluid kit in the forum mall? I recently purchased the kit and will be getting to it soon so any help is appreciated...

 

If you use the Redline gear lube, you do not need the limited-slip additive.


[Modified by Paul R, 8:03 AM 2/19/2002]