[JayD]

So from what I read, the correct part # for the diff fluid is
83222447362. supposedly this is a GL-5 75W-80 weight oil.

Looking at 3rd party suppliers like Motul competition gear oil. This is a 75W-140. oil. That is a big difference from the OEM weight. Is the OEM part # correct? Does the M2 diff take a different weight than the M3/M4?? not sure if any issues would arise running 75W-140

any info would be helpful.

thanks
Jay

[JustinHEMI]

That's the gist of what I was getting at in the following thread. I was surprised what I found when searching the part number vs what was the spec for my F87 rear end.

I felt better that everyone else was getting a similar part number, but I agree, there's still some questions about what's going in. BUT, if it's what they're calling for, I'm satisfied from a warranty perspective.

https://g87.bimmerpost.com/forums/sh....php?t=2020531

[DSTR]

First M-Service yesterday at exactly 2000km here in Germany. This is the BMW Diff fluid used by my dealer. I took a few pics of the service in progress.

[kyrix1st]

Great question.

It isn't uncommon to go higher viscosity depending on your vehicle usage. Going from 0W30 to 5W40 or 70W80 to 75W140 WILL NOT hurt your vehicle. If the vehicle is occasionally tracked and under warranty, I recommend using BMW's motorsport 75W140. (Note that F82 M4 had the exact same differential as that of G87, but had 75W140 for maximum protection)
https://www.bimmerworld.com/Fluids/D...222365988.html

For my moderate track/street usage, I use Motul X-cess Gen2 5W40 and Motul competition 75W140. I use the latter product on all my M3s from E36 to F82, never had an issue.

[KC87ZB]

Originally Posted by kyrix1st

Great question.

It isn't uncommon to go higher viscosity depending on your vehicle usage. Going from 0W30 to 5W40 or 70W80 to 75W140 WILL NOT hurt your vehicle. If the vehicle is occasionally tracked and under warranty, I recommend using BMW's motorsport 75W140. (Note that F82 M4 had the exact same differential as that of G87, but had 75W140 for maximum protection)


For my moderate track/street usage, I use Motul X-cess Gen2 5W40 and Motul competition 75W140. I use the latter product on all my M3s from E36 to F82, never had an issue.

Are you sure the F82 had the same variable slip differential that is currently available on the G8x models? I would expect that the variable slip capability might bring a higher level of stress on the lubricant and higher viscosities might not provide the correct amount of shear in a variable limited slip application.

[kyrix1st]

Originally Posted by KC87ZB

Are you sure the F82 had the same variable slip differential that is currently available on the G8x models? I would expect that the variable slip capability might bring a higher level of stress on the lubricant and higher viscosities might not provide the correct amount of shear in a variable limited slip application.

They both use GKN e-diff in 215mm case housing.
F82 M4:

G87 M2:


I have reasonable suspicion as to why lighter weight was used on G8x: to improve fuel economy, allow more rear braking to emulate locking differential effect and subsequently use less differential locking. Additionally, in 4WD application, rear differential doesn't see as much load as in pure RWD, so this specification was possibly carried from G82 xDrive.

I drive with TC fully off on all my M cars on a track, so I don't let the rear brakes engage for limited slip application. This naturally means more diff usage, and heavier weight makes sense because I'm letting the internal clutches do all the work.

[chris719]

We really don't know what internal changes have been made, but I still tend to believe you are correct here that the thicker fluid will be safe.