Diff noise?

[2FED]

Is this nosie is similar to nosie what produce chaning from N to R or from R to 1?
More, I hear two "clicks" then shifting from N to 2d gear (mean, using D with 1st mode it shifts to 2d gear instantly).
The same noise I hear sometimes from downshifting from 3d to 2d, or during moderate (not quite) breaking in D-mode then it downshifts to 2d and to 1st gear...

This sounds worry me very much, I don't know if it is normal or this can be solved?
I have askd for my BMW service, but they don't have any good expirencie on new M3...

[GregW / Oregon]

Originally Posted by 2FED

Is this nosie is similar to nosie what produce chaning from N to R or from R to 1?
More, I hear two "clicks" then shifting from N to 2d gear (mean, using D with 1st mode it shifts to 2d gear instantly).
The same noise I hear sometimes from downshifting from 3d to 2d, or during moderate (not quite) breaking in D-mode then it downshifts to 2d and to 1st gear...

This sounds worry me very much, I don't know if it is normal or this can be solved?
I have askd for my BMW service, but they don't have any good expirencie on new M3...

The transmission and diff are very much like the previous model's, or those of the M5/6, so drivetrain noise analysis should not be new. No, the sound is totally different, like the rear wheel is rubbing on the wheelwell liner in a tight turn.

[GregW / Oregon]

Originally Posted by GregW / Oregon

I'm getting a low noise on tight low speed turns. Might be the diff. I noticed on the 1,200 service there was not additive listed for the diff oil. I thought all the MLocks got it. The parts guy said only if they're "noisy".

The noise is hard to describe, but like a low rubbing sound, on both left and right hard turns. You can really hear it in a parking garage with the window down.

Update: Dealer replaced the diff fluid today with the one in quixs1lver's post. From the invoice:

"0053267 repl diff oil with special oil
5029 WBMW
3 83-22-2-282-583 final-drive gear oil (N/C)

Verified customer complaint per SIB 33 01 02. Replaced diff fluid and performed break in treatment. See attached bulletin. Break in procedure may take up to 600 miles."

I drove around my club's parking garage with tight corners and so far no noise.

6/30 update - noise is definitely gone

[MDCTFTW]

It needs to be broken in again? Strange.

[GregW / Oregon]

Originally Posted by MDCTFTW

It needs to be broken in again? Strange.

No, it's not a break-in, per se. It's just to get the fluid evenly coating everything.

[MDCTFTW]

Originally Posted by GregW / Oregon

No, it's not a break-in, per se. It's just to get the fluid evenly coating everything.

Ah I see. Well it's good the issue is fixed. Congrats.

[Radiation Joe]

Greg,
If you can live with the noise, I would leave it alone. Your diff is working the way it is supposed to. They can add more LS friction modifier, but then you'd have less of the effect the the LSD is there for, mainly less torque lock up.

If your diff doesn't make any noise under any circumstances, then you have no way of knowing (other than taking it through an auto-x) if the diff is doing it's job. I'd take that little groaning noise as a sign your car is healthy.

[GregW / Oregon]

Originally Posted by Radiation Joe

Greg,
If you can live with the noise, I would leave it alone. Your diff is working the way it is supposed to. They can add more LS friction modifier, but then you'd have less of the effect the the LSD is there for, mainly less torque lock up.

If your diff doesn't make any noise under any circumstances, then you have no way of knowing (other than taking it through an auto-x) if the diff is doing it's job. I'd take that little groaning noise as a sign your car is healthy.

What you say may be true, but do you have any facts to support that? I don't think the modifiers just make the fluid slipperier, but I could be wrong.

[Radiation Joe]

Originally Posted by GregW / Oregon

What you say may be true, but do you have any facts to support that? I don't think the modifiers just make the fluid slipperier, but I could be wrong.

"Compatible with petroluem or synthetic gear oils, Red Line Limited Slip Friction Modifier & Break-in Additive will significantly reduce the friction break-in of differentials, reducing break-in temps for as much as 50 degrees F. Limited slip or positraction units will often chatter without use of this product or a gear oil with a similar modifier, so add only enough to eliminate the chatter and avoid making the plates or clutches too slippery."
.
.

[ericld]

Okay - So I have the same issue on my E92 Coupe. It's a "cornering at low speed" situation and I get a rubbing groan sound - sort of a humming. I hear it daily when I turn into a parking place.

I knew it was the diff when I first heard it, but for a few minutes I thought it might be a wheel rubbing in its wheel well. I also wondered if some lug nuts were loose causing a rear wheel to rock up against the interior well wall.

As a group, what have we decided? Let it be or get more diff fluid in the unit?

I have 2700 miles, but it doesn't sound like something that will go away, more likely something that will increase over time. Friction increases, it doesn't go away over time.

[GregW / Oregon]

Originally Posted by ericld

Okay - So I have the same issue on my E92 Coupe. It's a "cornering at low speed" situation and I get a rubbing groan sound - sort of a humming. I hear it daily when I turn into a parking place.

I knew it was the diff when I first heard it, but for a few minutes I thought it might be a wheel rubbing in its wheel well. I also wondered if some lug nuts were loose causing a rear wheel to rock up against the interior well wall.

As a group, what have we decided? Let it be or get more diff fluid in the unit?

I have 2700 miles, but it doesn't sound like something that will go away, more likely something that will increase over time. Friction increases, it doesn't go away over time.

I had exactly the same as you describe. Per my post #25 above, the different fluid solved the noise immediately and completely, and I notice no difference in performance. I would recommend it.

[Tosh]

Same thing going on in my e90 sedan right now too. It's odd. I never heard it when I first got the car--only now after break-in. I have almost 3k miles.

OT, my mic in my Bluetooth went out today. They told me to erase the phone from the nav and take out the phones batteries for a few minutes. I did so, relinked it and now it works perfectly. Also, sometimes when I switch DCT off or to S5/6 my treble speakers go off intermittentl--which is strange as well. Don't know why that would be.

Back to original topic--basically, the turn noise is not bad as long as you can stand it? Is that the consensus?

[GT3 Tim]

I have not had the noise, but have previously owned cars with NOISEY diffs (the GT3 for one). This is a "normal" noise. Most diffs with higher lock-ups will make some noise, its the nature of the beast.

I am with Radiation Joe on this one. I would not add a modifier to reduce the noise. IMHO, you are retarding the effectiveness of the clutches....and thus, the overall performance thereof. Personally, I would live with the noise.

Now, for people that are basically city drivers that do not track, etc., it is really a moot point as you wont notice a reduction in lock-up in most cases. So, if that is the case, and you dont like the noise, go ahead and add it. Either way, the diff will still be under warranty.

[kosh]

Be cereful guys. I have 21 500km on my M3 and today I changed diff

Sorry for my english

[moog55]

I now have the diff noise as well. it's been there for about two weeks and now is annoying the shit out of me. i go in and out of a 5-level parking garage every day and so it's very easy for me to hear. same exact rubbing/grinding sound.

now that i've read this thread, i feel confident that greg has identified the problem and has a fix that seems to work for him. however, there are others here that are saying to leave it alone and that the diff sound is normal. what should i do here?

i have 2800 miles on my car now and also did not experience this prior to my 1200 mile service.

[GregW / Oregon]

Originally Posted by moog55

I now have the diff noise as well. it's been there for about two weeks and now is annoying the shit out of me. i go in and out of a 5-level parking garage every day and so it's very easy for me to hear. same exact rubbing/grinding sound.

now that i've read this thread, i feel confident that greg has identified the problem and has a fix that seems to work for him. however, there are others here that are saying to leave it alone and that the diff sound is normal. what should i do here?

i have 2800 miles on my car now and also did not experience this prior to my 1200 mile service.

If it bugs you, get it fixed. It will "cheapen" the car in your mind (and others). I seriously doubt there is much difference in limited slip action by going to the quieter fluid.

[moog55]

greg, i'm not sure what you mean when you say changing the diff fluid "cheapen" the car. i just don't want to make the fix if it has a potential to damage the car in anyway.

in any event, it does bother me and so i'm going to have this fixed. i printed out the thread and will bring it to my dealership tomorrow.

[GregW / Oregon]

Originally Posted by moog55

greg, i'm not sure what you mean when you say changing the diff fluid "cheapen" the car. i just don't want to make the fix if it has a potential to damage the car in anyway.

in any event, it does bother me and so i'm going to have this fixed. i printed out the thread and will bring it to my dealership tomorrow.

By cheapen, I mean in your mind the quality of the car is diminished because it is making noises. The diff fluid change I had done is an approved BMW TSB procedure and will now way cause any harm.

[moog55]

Originally Posted by GregW / Oregon

By cheapen, I mean in your mind the quality of the car is diminished because it is making noises. The diff fluid change I had done is an approved BMW TSB procedure and will now way cause any harm.

ahhh, i see. gotcha. in that case, i am leaving work right now to go talk to my service advisor. i definitely do NOT like the sound and want it to stop.

thanks.

[TTG]

Originally Posted by moog55

ahhh, i see. gotcha. in that case, i am leaving work right now to go talk to my service advisor. i definitely do NOT like the sound and want it to stop.

thanks.

Please keep us updated and let me know which dealership you are taking your car to.

[ALMM3]

Greg, I got the same noise, right after the dealership changed the diff fluids.. Good to hear it's not just my car. I almost lost my mind, I've only had my M3 since the 4th July and now it's falling apart, WTH! The Service Manager told me that he received a new service bulletin instructing him to use a special type of diff fluid and the noise should stop within 300 to 400 miles after the change. I'll keep you posted!

[GregW / Oregon]

Originally Posted by Mel Red

Greg, I got the same noise, right after the dealership changed the diff fluids.. Good to hear it's not just my car. I almost lost my mind, I've only had my M3 since the 4th July and now it's falling apart, WTH! The Service Manager told me that he received a new service bulletin instructing him to use a special type of diff fluid and the noise should stop within 300 to 400 miles after the change. I'll keep you posted!

As I noted, my noise stopped immediately after the change to the updated fluid.