Rear diff low fluid
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Instructor
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Melting Slicks
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From: Sugar Land TX
Le Mans Master
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From: Redmond WA
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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.
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Melting Slicks
Joined: Feb 2004
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From: Sugar Land TX
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.
Drifting
Joined: Oct 2014
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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.
Racer
Joined: Mar 2016
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you could change it all for $66 later at next oil change. Wouldn't hurt.
Melting Slicks
Joined: Sep 2005
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From: RACE TRACK USA
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?
Melting Slicks
Joined: Feb 2004
Posts: 3,131
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From: Sugar Land TX
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?
Le Mans Master
Joined: Sep 2003
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From: Longview Texas
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.
Melting Slicks
Joined: Sep 2005
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From: RACE TRACK USA
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.
Le Mans Master
Joined: May 2000
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From: Redmond WA
Any relationship between using non-GM oil and your multiple failures do you think? I won't tell, just curious...
Burning Brakes
Joined: May 2007
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From: turn 12 at Road America or TX
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 ...
Melting Slicks
Joined: Apr 2016
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From: Naples FL
Originally Posted by DAVE396LT1
Any relationship between using non-GM oil and your multiple failures do you think? I won't tell, just curious...