changing rear end fluid

[DCVING 6]

I would like to change the rear end fluid on my car.
What all do I need?
gasket?, which lube?, which addative?,

As far as actually doing it, just pop the cover off to drain it. Put cover back on, and fill up to where the plug is.

??????
Thanks

 

[325DR]

And to add to that...

Is the limited slip additive necessary? I have heard that you shouldnt use it if the car is at the track a lot....

 

[G McCall]

I use Redline brand rear fluid only without any additive.
Remove cover and clean out any debris (Shavings etc.). Replace cover with new gasket. Some may need to use a sealer if cover is warped or doesn't seal.

 

[machinegun]

Remove all the cover bolts. Pry off cover and let the unit drain into pan. Clean all gasket surafces. Gasket can be had at any parts store even the advance auto autozone and pep boys type places. You will need fluid. Some people have different opinions on this but I usually use valvoline or havoline. I personally use 80-90. I do not use synthetic. Go to your local GM dealer and ask for the POSI additive from GM. I have had the best luck with this product. Clean all the fluid from the diff. Using some high tack or gasga cinch, install the gasket on the cover and install cover torquing the bolts to GM specs. Remove the fill plug on diff. Forward passenger side. put in the GM posi additive. Now fill till fluid just comes out of the fill. I personally will heat up the fluid in a pan of boiling water. It is much easier to pour this way. Install plug, check for leaks and you are done.

 

[gn79]

HOW MANY BOLLETS OF THE GEAR OIL ARE YOU GUYS USING? I DID MY LAST NIGHT AND I PUT IN ABOUT 1 AND 3/4 OF OIL. NO ADD. I USED MOBIL 1 SYN. AND SOME GOT ALL OVER THE OUTSIDE WHEN I WAS TRYING TO PUT IT IN. THE HOLE WERE THE PLUG IS WAS SO SMALL I COULD NOT GET A FEEL FOR THE OIL SO I JUST WANT TO BE SAFE BE FOR I TURN ON THE CAR.

 

[machinegun]

one and 3/4 bottles should be just about right. It is tough to get in there and fill. Even with synth oil I would still add the modifier for the posi.

 

[G McCall]

About Synthetic rear fluid,
I used to have a big block camero with a Moroso Brute Strength heavy duty 12 bolt rear end.
Regular GM type rear end fluid with the posi. additive in this unit would not last even 1/2 as long as synthetic rear end fluid before the rear would start "chattering" around corners.
I have never gone back to regular fluid. Cost more but well worth it.

 

[Cleaner13]

not sure about you guys

but Eric Schertz of dynotech recommended that I use 2 bottles of GM additive and 2 quarts of 80/140 Pennzoil Gear oil
and its been quiet ever since

Carl

 

[GN ERGY]

I use MOBIL 1 synthetic with no additive, that is what they told me at Mobil when I called them. That was over 8 yrs ago and no problems.
Tarey D.

 

[DCVING 6]

so basically everyone has their own oppinions?

 

[red89notch]

Use Mobil 1 and check out the local GM dealer to see if additive is neccessary.

 

[fitz3820]

You might want to add a drain plug to the cover, makes it tons easier nex time. You can get one for a few bucks from Jegs/Summit. Get one for the tranny pan too.

Just drill a hole and locktite it on...

Mark Fitzgerald
87 GN 11.9 @ 115