Fluid change Question?
Thread Starter
7th Gear
Joined: Mar 2019
Posts: 7
Likes: 1
Fluid change Question?
Thanks upfront for the help
I have a 2018 M7 Z06 with 12,000 miles and have decided to change the rear axle and manual transmission fluid myself. I’ve had numerous issues with the GM dealership doing things right. They’ve way overfilled the oil, left oil drips on the paint, told me I needed 4 new rotors without taking the wheels off and tightened my lug nuts to over 140 when they did take the wheels off. Thus, I’m really going to try to do what I can myself.
I’ve seen multiple videos on doing the rear axle and manual transmission and it’s seems like something I can do but want to clear some confusion I’m having. It seems that rear axle and rear differential are used interchangeably.
For the rear axel I will be using dexron LS gear oil GM part # 88862624
For the manual transmission I will be using manual transmission fluid GM part # 88861800.
i believe I’ve watch the 2 videos above and no where they are located. However, the manual says for the ELSD clutch system use Dexron VI automatic transmission fluid. I don’t believe I’ve ever seen a video on this but want to make sure I’m not getting this and the rear axle fluid change mixed up. I’m guessing the ELSD clutch system is not something that we can change correct? Hope this make sense and thanks for the help.
I have a 2018 M7 Z06 with 12,000 miles and have decided to change the rear axle and manual transmission fluid myself. I’ve had numerous issues with the GM dealership doing things right. They’ve way overfilled the oil, left oil drips on the paint, told me I needed 4 new rotors without taking the wheels off and tightened my lug nuts to over 140 when they did take the wheels off. Thus, I’m really going to try to do what I can myself.
I’ve seen multiple videos on doing the rear axle and manual transmission and it’s seems like something I can do but want to clear some confusion I’m having. It seems that rear axle and rear differential are used interchangeably.
For the rear axel I will be using dexron LS gear oil GM part # 88862624
For the manual transmission I will be using manual transmission fluid GM part # 88861800.
i believe I’ve watch the 2 videos above and no where they are located. However, the manual says for the ELSD clutch system use Dexron VI automatic transmission fluid. I don’t believe I’ve ever seen a video on this but want to make sure I’m not getting this and the rear axle fluid change mixed up. I’m guessing the ELSD clutch system is not something that we can change correct? Hope this make sense and thanks for the help.
Burning Brakes
Joined: Feb 2018
Posts: 906
Likes: 196
From: Northeast, PA
I didn't cross check the fluids you listed to make sure they are correct. M7 trans should use ATF and the rear should use 75w-90 gear oil. You are correct about the ELSD, you aren't servicing that.
Drifting
Joined: Sep 2019
Posts: 1,913
Likes: 1,957
From: Colo Spgs, CO
You're on the right path, @Mike Ruffalo. The maintenance you're doing is pretty straightforward and eminently doable with basic tools. The biggest caution I'll offer is to ensure you can open the FILL plugs BEFORE pulling the pull the DRAIN plugs. Doing it the other way around can leave you unable to refill after draining the old fluids.
Tech Contributor
Joined: Oct 1999
Posts: 41,058
Likes: 9,821
From: Charlotte, NC (formerly Endicott, NY)
Don't touch the eLSD. It requires access and use of a dealer MDI tool to do the service. Rear axle/diff is serviced as a number of videos have shown EXCEPT for the final step. I haven't seen a video that addressed the final step in the service procedure. The final step is after the diff is refilled and fluid is within a half inch of the bottom of the fill plug hole or flowing out of the fill plug. At that point the fill plug is inserted and turned a few threads, followed by running the engine to bring rear wheel-speed to 10 mph for a period of one minute. After this check the fluid level again and top off if necessary, tighten the fill plug and lower the car.
Bill
Bill
Drifting
Joined: Jun 2013
Posts: 1,428
Likes: 478
From: Maryland, USA
I plan on doin the same fluid changes asap, I have the numbers saved from my manual, looks correct me.
Genuine GM 88862624 Differential Lubricant
Genuine GM Fluid 88861800 Manual Transmission Fluid
However I am looking to maybe get the redline d4 atf fluid for the trans
either way both need to be replaced or at least looked at since it seems no one cared to looked at my clutch fluid and it was empty....
Genuine GM 88862624 Differential Lubricant
Genuine GM Fluid 88861800 Manual Transmission Fluid
However I am looking to maybe get the redline d4 atf fluid for the trans
either way both need to be replaced or at least looked at since it seems no one cared to looked at my clutch fluid and it was empty....
Drifting
Joined: Jun 2013
Posts: 1,428
Likes: 478
From: Maryland, USA
I just found the delco fluid pretty cheap so just purchased 4 of each of those numbers only to ensure i have enough.
