My Rear Differential Experience

[kpowell9]

So got my M3 w/ competition package, DCT, in SSII about 5 or 6 months ago and have been loving it for the most part. I took delivery within a week or two of the disclosure by BMW of the rear differential issue. I knew my car had an affected RD, but I was told they wouldn't do anything until it was symptomatic. Anyhow, within the first month I heard a distinct "clank" sound when shifting in a low gear. It surprised me but I was also unsure whether it came from the car or perhaps from something I hit, or maybe I was just imagining it. I didn't hear it again (for a while), and everything seemed to be just fine so I kept driving. About a month later, same sound. I've heard this sound probably 8 to 12 times since I took delivery, and each time I had the same reaction. Just not sure what I was hearing, and it seemed random.

This past Thursday, as I was leaving the gym there was a definite clank sound again. This time I knew it wasn't just me because it caught someone else's attention. Immediately thereafter, I started noticing a strange sound between a hum, whistle, and grind that appeared to be coming from the rear and more to the passenger side of the car. That sound lasted about 30 seconds and then started fading until it was gone.

So I called BMW service and am not set to get the RD replaced. I probably should have insisted early on, because I have been a bit uneasy about the whole thing since I bought the car and not fully enjoying it.

I drove it to the dealer this morning (20 miles from my house) and didn't hear any problems. But the RD is getting replaced regardless of whether the service center can recreate the sound. BMW should be replacing these things on every car built during the recall period without question.

They couldn't order the part today since the warehouse is closed for the holiday, but I'm told I should get my car back by the end of the week.

I just thought I'd post this to let others know what to look out for.

Kevin

[jschweiger]

Just wondering, but who told you that they were not going to do anything with the rear differential until it was symptomatic? I don't think that this is not true. You might want to search for the several threads that discuss this issue for help.

If fact, I had my differential replaced last week. I took delivery in July a few days before the recall was announced. I had no symptoms, that only reason for the delay was availability of parts. Once i read about the recall, I took by call in, they say that yes I was affected, and ordered the parts in late July.

Hope that helps.

Jeff

[sandwi54]

Looks like you are late to the party. There were many, many rear diff threads on delivery stop and recall campaign between the months of July and Nov. I'm surprised your dealer didn't contact you to come in for the diff replacement as it was required for all cars manufactured during the period when the rear diff was found to be faulty.

[kpowell9]

Originally Posted by jschweiger

Just wondering, but who told you that they were not going to do anything with the rear differential until it was symptomatic? I don't think that this is not true. You might want to search for the several threads that discuss this issue for help.

If fact, I had my differential replaced last week. I took delivery in July a few days before the recall was announced. I had no symptoms, that only reason for the delay was availability of parts. Once i read about the recall, I took by call in, they say that yes I was affected, and ordered the parts in late July.

Hope that helps.

Jeff

I took delivery about the same time, and at the time I took delivery I had them check and at first they said I wasn't affected, then I told them I had checked online and knew my car was affected based on the serial. They then confirmed I had a recalled RD but told me they weren't doing change outs unless/until an issue arose. That came from the service rep. I should have insisted but really didn't know enough I guess. Anyhow, it's getting replaced now.

[kpowell9]

Originally Posted by sandwi54

Looks like you are late to the party. There were many, many rear diff threads on delivery stop and recall campaign between the months of July and Nov. I'm surprised your dealer didn't contact you to come in for the diff replacement as it was required for all cars manufactured during the period when the rear diff was found to be faulty.

Peake BMW in New Orleans is my dealer. Like I said, I asked them about it and they said it wasn't an issue unless I started having symptoms.

[spyderbret]

I took mine in last week for the break in service and to address a slight pull to the right. I was not having any symptoms but they said min was part of the RD recall so they are replacing it while they have it. Maybe it depends on the store but if I knew mine was on the recall list I would insist it be replaced. Better safe than sorry....

[jschweiger]

Originally Posted by kpowell9

Peake BMW in New Orleans is my dealer. Like I said, I asked them about it and they said it wasn't an issue unless I started having symptoms.

Interesting! I will say that in my opinion, this recall has been was handled really badly by BMW. From the start, the information about what exactly was the issues, how/when it is to be replaces, the delivery stop, etc. was given to people in drips and drapes. I got more info on what was going from this forum.

What your dealer said seems to be a new one. I thought all diffs where going to replaced at some point. Sounds like you are getting you issue fixed in any event, so that sounds like good news.

[backagain]

I was told they were still short of replacement parts at the end of Oct, the time I suppose to get it done based on the acknowledgement letter (for the replacement campaign) I signed when I took delivery. I waited 6 more weeks as I don't have any problem with the RD, and decided to have it done during Christmas when I won't need the car. So called BMWNA and asked for a case manager to be assigned. Two days later, the dealer called and wanted me to bring the car in.

As to the noise that OP was talking about, I've had very similar experiences, with the old and the new, replaced RD. I agree it is coming from the passenger side. It usually happens when I make a quick lane change. The 1st time it happened, I thought I drove too close to the curb, and burned the wheel. Just yesterday when it happened again, my 12-year son turned to me and gave a look that said, "what the heck did you do to your car?"

I think it is due the fact RD is directly bolted to the chassis, therefore, whenever it kicks in strong (such as in fast lane change), you can feel/hear it. The manual has some verbiage to that effect.