Z06PA

3 quarts.

8850

Owners manual says Dexron LS gear oil but not how much. Refers to how to fill.

Z06PA

Not for the differential it doesn't.

This is the fluid for the rear:

ACDelco 10-4034 Dexron LS 75W-90 Gear Oil

8850

You are correct. I read Electronic Limited-Slip Differential but then it says Clutch System Lubricant.

davepl

Correct, which is the Amazon link I posted up above! 10-4034.

23/C8Z

If this has already been discussed than I apologize.

Maybe the low level is because of the rear differential cooler lines after installation of rear at factory?

capevettes

See my post, 10, earlier in this thread. I think you are correct. The pumpkins are filled by the suppliers. Once the car is driven, the rear ends need to be topped off. Maybe BG should rotate the rear wheels, check the level and top it off.

MIGHTYM0USE

this stuff the same as any other syn gear oil?

8850

Would there be any problem of topping off with AC Delco 10-4016? It's the same synthetic 75W-90 but without the limited slip additive so I've read. Car is jacked up ready to add but 10-4034 isn't available today.

5thGear

My 2 cents, I wouldn't. I doubt anyone here has done it and ran it long enough to answer this question so why risk it, Just keep it simple and do it by the book.

Spacewalker

wrong non ls oil would be better than low oil

you could change it all for $66 later at next oil change. Wouldn't hurt.

cvp33

I replaced 3 diffs (warranty) in my CTS-V. All began to sing after 5K miles with the GM synthetic. Switched to Royal Purple 75/140 max gear oil and ran another 15K miles and 10 track weekends with no other issues. I believe the RP has a higher heat tolerance but I have nothing to back that up. Thoughts?

8850

I have two quarts of Royal Purple already and could pick up a third today at my local parts store. Maybe a better choice???

TEXHAWK0

I don't think it is a mistake that the rear ends are at the lower level on fluid. Up to 1/2" below the hole is supposed to be an acceptable level, even though most people have always filled it up to the bottom of the hole. Since the rear ends are filled at the manufacturer, maybe some accountant decided they could save money by only filling to the acceptable lower level.

cvp33

I don't want anyone to screw up their rear diff. I used RP with friction modifier. I had a member PM and say that RP has the wrong friction modifier. While my experience was better with RP in my CTS-V, I don't want to cost someone their rear diff. Sorry for any confusion.

spearfish25

My CTS-V ate two diffs as well. Even the third would whine but I gave up. Any time I tried a non-GM oil it would chatter despite adding the slip additive.

8850

I bought a quart of the real GM stuff (10-4034) and topped it off. All full now! GM owes me!

davepl

Any relationship between using non-GM oil and your multiple failures do you think? I won't tell, just curious...

gbrtng

BG cars are run on a dyno so doing a fill up afterwards should be part of the preparation before shipping. Somebody should have changed the final process by now ...

spearfish25

No sir. My first diff started whining after 3,000 miles on the GM fluid. They swapped it and the second one got about 10,000 before puking fluid out the breather valve, also with GM fluid. The third one whined from the moment I drove it out of the service area but I had given up by then. That's when I tried Amsoil with the GM additive and it chattered on turns. Drained and refilled with the GM juice and no more chatter but it still whined.