[rahimhussainar@gmail.com]

What are some of the main symptoms to look out for?
I got clunk and whine.

Is the clunking only apparent in a specific manner?

For my car, if I am just cruising at like 2-3mph or a really low speed, and then press on the gas casually, the car will jump forward or jerk forward. But it does this inconsistently.
I have an xdrive tho so idk if that changes things.

Other than that I can’t notice much

[xnick101]

I have that clunk when you take off kind of hard at low speed. I heard that has to do with something else back there. But yes if you have a grinding sound at WOT its likely the diff has metal in it.

[F32Fleet]

Originally Posted by rahimhussainar@gmail.com

What are some of the main symptoms to look out for?
I got clunk and whine.

Is the clunking only apparent in a specific manner?

For my car, if I am just cruising at like 2-3mph or a really low speed, and then press on the gas casually, the car will jump forward or jerk forward. But it does this inconsistently.
I have an xdrive tho so idk if that changes things.

Other than that I can’t notice much

Low speed noises can be normal on an clutch based LSD.

[hayko_M340]

Revisiting thread once again, at 47K miles. Warranty ends in 3K, gotta take it in service before it ends. Last time at 41K miles dealer noted it was "Sweating" by breather hole and normal per SIB. Also noted car was lowered on Dinan springs and aftermarket wheel which was supposedly what added on to it, yea right lol. Is there actually a redesigned diff cover and does it actually fix the leak or would it be pointless to put the car back to stock and take it in again. Any info greatly appreciated. When was this supposedly updated diff cover released? Vehicle is a February 2020 production date. Per dealer "performed visual inspection found rear differential is not leaking it just appears sweating from differential
cover per sib 330321 it is normal, upon inspection found that incorrect tires size are installed in front and rear.
Advise customer this can cause premature wear to the driveline.vehicle
equipped with aftermarket suspension and wheel and tires will contribute to creaks."

[xnick101]

Yes, the new part # diff cover has revised breather holes which does resolve the leak. After BMW replaced my diff cover it has never leaked again.

[hayko_M340]

Originally Posted by xnick101

Yes, the new part # diff cover has revised breather holes which does resolve the leak. After BMW replaced my diff cover it has never leaked again.

Do you have part # by any chance? Was it 33-11-8-742-755 or is this the old one? Thanks.

[xnick101]

Originally Posted by hayko_M340

Do you have part # by any chance? Was it 33-11-8-742-755 or is this the old one? Thanks.

I believe so, that's the new part number that shows up on realoem as well. You can go to the BMW parts department and they can confirm it as well as they can see the dates on the part numbers.

[thatm340i]

I got my rear differential seal replaced they dropped the rear diff in order to do it and now i have a error code saying rear diff axle lock reduced does this mean i have to get it reprogrammed or recalibrated

[Austin027]

Hey I just bought my 2020 M340i with 23k miles and I'm getting gear oil leaking from the rear up top. I read this entire post multiple times and some people say part number 33-11-8-677-753 fixed the issue and some say 33-11-8-742-755 is the fix. I'm trying to make sure I get the correct differential cover so I don't have to do the job twice. Thanks for the help

[huzidada]

What years M340i do these affect? When was the old cover superseded with the new one?

[Davg31]

Originally Posted by Austin027

Hey I just bought my 2020 M340i with 23k miles and I'm getting gear oil leaking from the rear up top. I read this entire post multiple times and some people say part number 33-11-8-677-753 fixed the issue and some say 33-11-8-742-755 is the fix. I'm trying to make sure I get the correct differential cover so I don't have to do the job twice. Thanks for the help

33-11-8-742-755 this one was fitted on cars before 2019, reference 33 11 8 677 753 from 02/2019, so it would be logical to assume that it's the correct version (plus it costs 4x less, which is often the case when it's the reliable version).

[Davg31]

After checking, one would be for sdrive, the other xdrive, however no idea how to recognize a corrected version (new oil breather).

[none64]

So, anyone could confirm the right part number for RWD US spec M340i?

[Planoser]

Hello,
I just replaced my m340i rear diff cover with the updated part number and new BMW diff fluid. Now I have the error code about the -Rear axle differential lock reduced-. Did anybody ever figure out the cause and solve for this? Appreciate any help you can offer.

THANKYOU!

[cyam]

Originally Posted by Planoser

Hello,
I just replaced my m340i rear diff cover with the updated part number and new BMW diff fluid. Now I have the error code about the -Rear axle differential lock reduced-. Did anybody ever figure out the cause and solve for this? Appreciate any help you can offer.

THANKYOU!

I got mine fixed under warranty, but it took them several times to get it right. The first couple of times they did not replace the cover with the updated version. First time they replaced the seal, second time they replaced the cover, but with the same type. Third time they changed the cover with the updated version.

Now when they did the second attempt and replaced the cover, they had your issue. They were getting the diff error/locking reduced error.

I was informed that they needed the number that was stamped on the original diff cover or something and they had to make some change via software. There is software that controls the diff and it seems it needs a number. They took a week as they had to get this new number from Germany.

When they did the third attempt, the service advisor made a special note about the numbers and ensuring they had them so they didn't do the same thing.

Sorry, very wishy-washy answer. But this was an actual BMW dealership, and this was what I was told. I didn't ask more detailed questions, as it didn't really matter to me.

Maybe this will help you.

[water777]

Originally Posted by Planoser

Hello,
I just replaced my m340i rear diff cover with the updated part number and new BMW diff fluid. Now I have the error code about the -Rear axle differential lock reduced-. Did anybody ever figure out the cause and solve for this? Appreciate any help you can offer.

THANKYOU!

How much was the diff cover?