E92 M3 broken differential bolt

[mhabs]

Maybe you can take that evidence (i.e. pictures) and get a second opinion from an independent specialist that is trustworthy while also finding out if can be done cheaper.

Having said that, I had my differential nearly fall out of the rear and luckily was covered by warranty. I had been complaining about it for over a month, and they gave the all clear the first time around, so probably was more an "open and shut case" because they gave a clean bill of health after I brought up the potential issue. Also, I had no impact, aggressive driving/tracking/launches/mods and someone from BMW NA did have to look at it and approve it (that's standard operating procedure for this type of expensive issue). Despite it being covered by warranty (where one could argue they could have done the minimum to fix the problem), they replaced the differential, rear subframe, fuel tank and part of the exhaust, claiming there was damage to each of these components because of the differential nearly falling out. The "list" price on all this stuff ( I saw the work order) was over $13k.

You may also want to bring it up with BMW NA, or try to negotiate with the dealer if feel you can further argue the evidence is 100% conclusive that the bolt snap was impact related (2nd opinion also), given the prevalence of this issue. The mere threat of having the car towed to someone else may help your negotiating position (the dealer does include some margin on this type of stuff). Don't think anotherBMW dealer would yield better results, since the BMW NA reps that approve these typical service other dealers in the area. Perhaps a conversation with BMW NA and/or the BMW NA rep that looked at your car may yield more cooperation/better results. Best of luck.

Originally Posted by bvanderbilt

I am affected by this and joined this forum as a result of reading this thread.

I have a 2011 (100% stock, never modified) with 25k miles on it. I currently own three M3s -- two E46s and this E92. The E92 is my 'happy' car, I love the near-telepathic throttle response and drive it after particularly long days to unwind. The car (unlike my E46s) has never seen the track, has never been abused, and has never even had a bent 19" rim.

I took the car to the dealer (where I purchased the car) after hearing a faint clunking noise from the rear. A week later I am handed a "quote" for $6000. The differential bolt is broken off at the bushing. The dealer claims the sub-frame must be replaced. The dealer had an "FSE" come look at the car, who claims the car has had bottom impact damage.

I asked to see the damage myself and the damage is an inch long maybe 1/8" deep scratch to the passenger side fuel tank and some wear on a few of the differential fins, maybe from kissing a speed bump or road debris?

The dealer wants to replace the subframe, differential bushing & bolts, and fuel tank. They claim due to the "impact" it is not a warranty issue and I have to go through insurance.

I have a perfect driving record; going through insurance will be an at-fault accident which is unacceptable to me. I did not hit anything with the car and I have a hard time believing the fuel tank damage (a scratch, basically) is correlated to the differential, especially since the fuel tank sits higher than the exhaust and there is no exhaust damage whatsoever.

Dealership technician confirmed they found no hints of abuse whatsoever and could tell I took really good care of the car, saying it was "perfect" -- but claim they have never seen a broken differential bolt before and it must have been caused by impact. They also claim that it is BMW's decision and not theirs since the FSE wrote it up as accident damage.

Not sure how to proceed, advice appreciated. I think I could have the car towed to a reputable independent and have a new bushing and bolt installed at minimal cost, since this appears from this thread to be a relatively common issue, but I feel cheated by the dealer and their response.

[Mike Benvo]

Originally Posted by bvanderbilt

I am affected by this and joined this forum as a result of reading this thread.

I have a 2011 (100% stock, never modified) with 25k miles on it. I currently own three M3s -- two E46s and this E92. The E92 is my 'happy' car, I love the near-telepathic throttle response and drive it after particularly long days to unwind. The car (unlike my E46s) has never seen the track, has never been abused, and has never even had a bent 19" rim.

I took the car to the dealer (where I purchased the car) after hearing a faint clunking noise from the rear. A week later I am handed a "quote" for $6000. The differential bolt is broken off at the bushing. The dealer claims the sub-frame must be replaced. The dealer had an "FSE" come look at the car, who claims the car has had bottom impact damage.

I asked to see the damage myself and the damage is an inch long maybe 1/8" deep scratch to the passenger side fuel tank and some wear on a few of the differential fins, maybe from kissing a speed bump or road debris?

The dealer wants to replace the subframe, differential bushing & bolts, and fuel tank. They claim due to the "impact" it is not a warranty issue and I have to go through insurance.

I have a perfect driving record; going through insurance will be an at-fault accident which is unacceptable to me. I did not hit anything with the car and I have a hard time believing the fuel tank damage (a scratch, basically) is correlated to the differential, especially since the fuel tank sits higher than the exhaust and there is no exhaust damage whatsoever.

Dealership technician confirmed they found no hints of abuse whatsoever and could tell I took really good care of the car, saying it was "perfect" -- but claim they have never seen a broken differential bolt before and it must have been caused by impact. They also claim that it is BMW's decision and not theirs since the FSE wrote it up as accident damage.

Not sure how to proceed, advice appreciated. I think I could have the car towed to a reputable independent and have a new bushing and bolt installed at minimal cost, since this appears from this thread to be a relatively common issue, but I feel cheated by the dealer and their response.

Scares the hell out of me.. 46K almost now on my baby.

I do get that wheel hop now and again when the wheels are spinning... No clunking or anything abnormal yet (*knocks on wood*)

Really tired of hearing stories about BMW's failure to take responsibility for things like this and their propensity to incessantly blame the owner.

[L4ces]

Originally Posted by mitch32

Wow, we should honestly make a class action suite against BMW. These bolts should not fail, I never heard of another car doing this minus e36 m3s. I've heard of many ppl breaking axles on other cars never diff bolts. A $500 axle vs $10,000 diff cause of bolts is just mind boggling.

+1000
I'm out warranty and it is a concern.

[biggynuts01]

Originally Posted by mitch32

Wow, we should honestly make a class action suite against BMW. These bolts should not fail, I never heard of another car doing this minus e36 m3s. I've heard of many ppl breaking axles on other cars never diff bolts. A $500 axle vs $10,000 diff cause of bolts is just mind boggling.

I agree. Im in for a class action suit!

[hk328]

Is there any TSB or anything like that on this problem? This seems to be a worthy TSB even though the evidence may be anecdotal.

I have 2012 model and I was assuming this would be for earlier models, but it seems it is a slate 2011 models according to this thread.

A bit disappointed to think that these cars are meant to be driven hard but at the same time you have to think whether it will cause damages such as this....

[e92zero]

wonder if the DEFIV diff brace is our solution: http://www.m3post.com/forums/showthread.php?t=814736

[1fast lorinser]

Just a quick update, for all you guys who think that this issue is corrected on the newer model m3's your wrong. I have a 2013 M3 with only 800 miles and my bolt snapped and even may have internal differential issues. service is trying to say it was caused by my driving and crap. They are awaiting for bmw to come look at the car. I dont care what anyone says im not fixing it out of my own pocket and if it happens again I will start a law suit because were driving $80k Bmw's that cant take a bit or real world driving styles. Ridiculous !

[Lute]

Originally Posted by 1fast lorinser

Just a quick update, for all you guys who think that this issue is corrected on the newer model m3's your wrong. I have a 2013 M3 with only 800 miles and my bolt snapped and even may have internal differential issues. service is trying to say it was caused by my driving and crap. They are awaiting for bmw to come look at the car. I dont care what anyone says im not fixing it out of my own pocket and if it happens again I will start a law suit because were driving $80k Bmw's that cant take a bit or real world driving styles. Ridiculous !

These bolts snap 99% of the time due to driver abuse and launching. The M3 is not meant for that, regardless of whether its an $80K car

[crashish]

Originally Posted by Lute

These bolts snap 99% of the time due to driver abuse and launching. The M3 is not meant for that, regardless of whether its an $80K car

Oh, really? 99%? Care to provide a source for that figure? What kind of driving is an M3 meant for, and how much of that do you think can actually happen within 800 miles?

Please note: the above is not to imply that I believe his particular case warrants a class action lawsuit or even a warranty repair. I simply don't think any of us in this thread can cite any hard numbers about this situation, much less any real facts of any relevancy, except for those few people who have dealt with this specific problem directly or who work for BMW.

If you work for BMW or have had your diff bolt snap, I apologize, particularly in the latter case.

[meko]

Lute, that is not an acceptable answer and its not acceptable for the diff bolt to break even WITH abuse. This does not happen on other performance cars even within BMW lineup. Look at M5 or even M3 GTS. They use a different setup. Drivers habits should be taken into account and testing should have uncovered it.

[1fast lorinser]

Originally Posted by meko

Lute, that is not an acceptable answer and its not acceptable for the diff bolt to break even WITH abuse. This does not happen on other performance cars even within BMW lineup. Look at M5 or even M3 GTS. They use a different setup. Drivers habits should be taken into account and testing should have uncovered it.

Exactly!!!
My car is still being broken in untill I hit my 1200 mile maintenance and I babies the crap out if this car and only did a few down shift pulls on the highway and nothing exceeding 5k Rpms which is safe. Reguardless iv had many sports cars and high end cars like cl65 amg, Porsche, Vettes and all of them were all pumping out at minimum 500hp and iv never had such a stupid problem like this which just comes down to poor design and not enough testing. Makes me want to tell BMW to keep there car! No excuses for some stupid crap like this and try and tell the buyer that the $80,000 doller BMW M3 they bought broke because if there driving style.

[mhabs]

It's highly probable that BMW is covering way more than 1% of bolt snap issues (as they did with mine). If that is true then it isn't only driver launching issues causing bolt failure failure. The differential design was changed in the M5, M3 GTS/CRT, and will be the case for all future M cars, including the new M3/M4. That fact alone in and of itself is an admission of a design flaw and taken together with quite a few M3 owners' getting bolt snap/full differentials replaced under warranty would point to the same conclusion, i.e. design flaw.

[1fast lorinser]

Just a update for you guys.
Finally herd back from the dealer with my car being there for almost a full 7days and still have not got it back. So the service advisor says that we want to make our customers happy and blah blah and we will repair your car and all but you have to come in and sign a document stating that this damage was due to drivers error and if it ever happens again they will not cover it. That's complete bullshit and I will not be signing no such forum. If it happened at 800 miles it will most likely happen alot more then once between now and 50,000 miles! Taking the matter to my lawyer so just a heads up to all u fellow e92 m3 owners don't give these people a dime and fight for what's right.