2011 M3 rear differential noise in tight right turn?

Car is a 2011 w/ DCT. Never noticed this before. So over the last couple weeks I have noticed while making a fairly sharp right hand turn into the parking lot (it goes up hill slightly) that I turn into every morning, there has been a faint noise coming from the right rear wheel. It sounded almost similar to a thud or thump, so I thought maybe it was something in the trunk sliding around. After it happened a couple of times when there was nothing in the trunk, I attributed it to noisy tires sliding across the asphalt (I am on 18" OEM winter wheels and tires at the moment). I didn't think any further of it, until tonight.

I was in a parking lot and decided to do some tight right hand turns to see if I could reproduce the noise. Alas, on a tight right hand turn going up hill slightly, I heard the noise in the back right wheel. This time it sounded like the wheel was rubbing the fender liner. I did as thorough of an inspection as I could last week when I had the car on a lift of all suspension/steering components, and nothing looked worn and saw no signs of anything leaking. Subframe bushings, rear control arms bushings, everything looked good. So the only thing I can think of is it is coming from the rear differential.

I've done some Googling, and it's apparently a common noise for the E90 (just like the E46) especially after the 1200 mile service. My questions are:

1. Does this sound like it is likely the rear differential?

2. If not the rear differential, what else could it be?

3. If it is likely the rear differential, is this cause for alarm, or fairly normal?

The car has 45,000 miles, and I was planning on doing a DCT fluid and rear diff fluid change next oil change (in 8 months) but should I do it earlier, or would I be okay to wait? The car had its 1200 mile service around 700 miles (don't know why it was so early, but it was).

Any input is appreciated. I am only concerned because it is a noise that had started within the last couple weeks. If it had always done it I wouldn't be so worried.

Normal. Use the diff fluid with the additive

What ^ said. Change it out and your problem should go away.

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Car is a 2011 w/ DCT. Never noticed this before. So over the last couple weeks I have noticed while making a fairly sharp right hand turn into the parking lot (it goes up hill slightly) that I turn into every morning, there has been a faint noise coming from the right rear wheel. It sounded almost similar to a thud or thump, so I thought maybe it was something in the trunk sliding around. After it happened a couple of times when there was nothing in the trunk, I attributed it to noisy tires sliding across the asphalt (I am on 18" OEM winter wheels and tires at the moment). I didn't think any further of it, until tonight.

I was in a parking lot and decided to do some tight right hand turns to see if I could reproduce the noise. Alas, on a tight right hand turn going up hill slightly, I heard the noise in the back right wheel. This time it sounded like the wheel was rubbing the fender liner. I did as thorough of an inspection as I could last week when I had the car on a lift of all suspension/steering components, and nothing looked worn and saw no signs of anything leaking. Subframe bushings, rear control arms bushings, everything looked good. So the only thing I can think of is it is coming from the rear differential.

I've done some Googling, and it's apparently a common noise for the E90 (just like the E46) especially after the 1200 mile service. My questions are:

1. Does this sound like it is likely the rear differential?

2. If not the rear differential, what else could it be?

3. If it is likely the rear differential, is this cause for alarm, or fairly normal?

The car has 45,000 miles, and I was planning on doing a DCT fluid and rear diff fluid change next oil change (in 8 months) but should I do it earlier, or would I be okay to wait? The car had its 1200 mile service around 700 miles (don't know why it was so early, but it was).

Any input is appreciated. I am only concerned because it is a noise that had started within the last couple weeks. If it had always done it I wouldn't be so worried.

I had exactly the same problem , and a lot of people !
You need differential fluid part # 832 222 82 583, which is SAF-XJ + FM Booster.
Please read this => http://www.m3post.com/forums/showthread.php?t=722833

FYI, I've gone through two changes with the new fluid which I paid for at the dealer and have driven another 1500 miles that they said it would take for the noise to go away. It still is there. They are reluctant to replace the diff under warranty.

Had the exact same problem with diff grinding. Only mine was worse after they attempted to fix, there shouldn't be any hesitation on their part to replace. Mine was replaced under warranty with fewer that 20k KM's. Could always try a different dealer if you have the option, which is what I would do because that shouldn't cost you a thing. If you are getting charged then they are picking your pocket.

Change fluid with booster = problem solved!

If the sound is the diff ... Do NOT use the booster stuff unless you have chatter. Groaning noise with a limited slip diff is NORMAL, chatter is not. The FM boosted stuff will lessen the diff's ability to lock.

My diff grinds and grabs. It shakes the whole car making turns. It started doing it at 35k miles or so.

TX wrote

My diff grinds and grabs. It shakes the whole car making turns. It started doing it at 35k miles or so.

Constantly, during turns, when cold?

warm or cold, going through parking lots and gas stations or any other sharp turn the rear diff grabs and will shake the car. It makes a very loud whomp whomp noise during that also.

TX wrote

warm or cold, going through parking lots and gas stations or any other sharp turn the rear diff grabs and will shake the car. It makes a very loud whomp whomp noise during that also.

What is the diff fluid change history? It sounds like a bad case of chatter.

thekurgan wrote

What is the diff fluid change history? It sounds like a bad case of chatter.

i took it to the dealer to look at and they told me I needed the fluid changed with the new fluid. that was around 35K or 37K miles. They changed it twice. I now have about 1500 miles or so maybe 2K miles on that new fluid and it's still doing it.
Prior to 35K it was the original fluid.

TX wrote

i took it to the dealer to look at and they told me I needed the fluid changed with the new fluid. that was around 35K or 37K miles. They changed it twice. I now have about 1500 miles or so maybe 2K miles on that new fluid and it's still doing it.
Prior to 35K it was the original fluid.

You might have worn plates internally. Maybe try doing several figure 8's in a parking lot to distribute the fluid.

thekurgan wrote

You might have worn plates internally. Maybe try doing several figure 8's in a parking lot to distribute the fluid.

I did the 20 full stop right and full stop left turns already. No improvement.
I'll have to go back to the dealer and see if they will change out this diff.

On my e46 m3 I had the same issue, changed everything including diff. Then finally someone suggested I change the rear abs sensor, and guess what... Presto it cured the problem..

Not to beat a dead horse, but I am still concerned about this, although no one else seems to be

The noise is getting more pronounced (showing up more often) and slightly worse. I know everyone says this is normal for LSD differentials, and it is common on the E46 and E9x platforms, but the car was 45k trouble free miles before this noise started. The differential wasn't making noise until recently, so something must have changed to make the noise start. Is it low fluid/a differential leak? Old/bad fluid? Worn clutch plates? Some other part in the differential going bad?

There also seems to be some mixed opinions on whether or not to use the fluid with the FM booster. I am definitely changing my differential fluid, but which one I put in is the question.

Should I be worried that this noise started a few weeks ago and is progressively getting worse? I hear it more frequently on lighter turns and I am afraid my differential is on its way out. Am I overreacting? Again, people say the noise is "normal", but the fact that it wasn't there for 45k miles and now is leads me to believe it started for a reason. The question is what would that reason be?

Most of the cases I have read about are old reports from years back and involve cars with low miles (3000 or less) and the "wrong" fluid. I haven't read any "my car has 45k miles and started making weird noises" cases, but would the fact that it went 45k miles before showing these noises indicate it is something more serious, or are people pretty confident changing my differential fluid (with either the normal OEM stuff, or the newer stuff with the FM booster) fix the issue?

The friction modifier that keeps the "clutches" quiet in your Viscolok diff does not last forever. If a fresh fluid change (with friction modifier) does not solve your noise issue, then worry about it. The fluid change will take some number of driven miles to take effect and quiet the diff, maybe a day or three of use.

BMW has switched to the new FM booster fluid which has a more aggressive abrasion formula which grinds down the plates causing the noise to go away, but the down side is it also changes the way the rear diff locks. I've gone through 1 change with the stock fluid and 2 changes with the FM booster stuff. The noise is still there. The diff was noise free until about 32K miles. I'm in the point of view now that the dealer now needs to change the diff under warranty.
BTW the dealer wants around $400 for the rear diff fluid swap. They say the fluid is a maintenance item and is not covered under warranty.

TX wrote

BMW has switched to the new FM booster fluid which has a more aggressive abrasion formula which grinds down the plates causing the noise to go away, but the down side is it also changes the way the rear diff locks. I've gone through 1 change with the stock fluid and 2 changes with the FM booster stuff. The noise is still there. The diff was noise free until about 32K miles. I'm in the point of view now that the dealer now needs to change the diff under warranty.
BTW the dealer wants around $400 for the rear diff fluid swap. They say the fluid is a maintenance item and is not covered under warranty.

The new fluid allows too much slip, yep, use too much FM booster and you may as well have an open diff.

The diff on my '11 w/33k miles was very noisy. Had the fluid changed last month, but took about 200 miles for it to get quieter. Now it's almost silent at slow tight cornering.

TX wrote

BMW has switched to the new FM booster fluid which has a more aggressive abrasion formula which grinds down the plates causing the noise to go away, but the down side is it also changes the way the rear diff locks. I've gone through 1 change with the stock fluid and 2 changes with the FM booster stuff. The noise is still there. The diff was noise free until about 32K miles. I'm in the point of view now that the dealer now needs to change the diff under warranty.
BTW the dealer wants around $400 for the rear diff fluid swap. They say the fluid is a maintenance item and is not covered under warranty.

They tried this on me too. Tell them to look up service bulletin SI B33 01 02.
It specifically says it will be covered under warranty which they eventually honored for me.

Here's a link to the bulletin

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CB8QFjAA&url=http%3A%2F%2Fwww.m3post.com%2Fforums%2Fattachment.php%3Fattachmentid%3D1143215%26d%3D1421323193&ei=fkICVY2-A9KHsQSi5YKwAQ&usg=AFQjCNEA5fXw411mdvZrNb1HOqqJI61_qA&sig2=7xkK9OuEfkcuigcahhHRgw&bvm=bv.88198703,d.cWc