[paul e]

As stated, I am getting a noticeable "clunk" when the car is braked in Reverse only. Plus it doesn't seem to happen every time, only when the car has been sitting.

I'm away from my home - 1100 miles away - for my late Mom's services, staying at the house I grew up in. We are jockeying the cars in the driveway, just like when we all lived here as teens.

As I was backing it up slowly in reverse, I was tapping the brakes, heard the clunk a few times in a row. The next day, I backed up a bit quicker and hit the brakes harder, got the clunk only once and couldn't repeat it. Haven't tried yet today.

I'm going to bring it into the local BMW dealer (North Haven, CT) but I'm wondering if the community here has any thoughts.

Thanks.

[kern417]

maybe a diff bushing or something similar.

[cfm56d7b]

Does this problem happen every time? As long as the symptoms can be consistently replicated, the dealer will find the root cause.

[paul e]

NTF. All is secure and tight. Unable to replicate.

[skier219]

Often times something like this may be due to the brake pads moving ever so slightly inside the calipers. If it happens the first time you brake in reverse but not the second time you brake in reverse, then it's a good suggestion this is the problem. If you alternated reverse, then forward, then reverse, you may hear the noise in both directions (but one of them may be easier to hear). If someone is standing outside of the car when this happens, they should easily be able to trace the noise to the offending wheel and brake. Normally this isn't a serious problem, but it could be indicative of a pad where the lining broke loose from the backer, or the pad guides/slides are worn. So I'd get it checked out if in doubt.

[chenry]

So I know this is an old thread, but figured better to resurrect vs starting a similar thread.

So my car (2017 340) has suffered from this condition since it was new, dealer could never duplicate the noise, thus it went unfixed. Until my most recent visit, the car is in due to a rock going through the radiator (yes another one of those) while there I was able to produce the "thunk" and SA sent me a message yesterday stating:

the foreman found an update to the driveshaft causing the clunk noise on your car! There is some hardware and loctite that needs to be ordered and it should be here in a couple days

Anyhoo maybe that will help someone if they are experiencing the same. I'll post a picture of the service order when I get it back

[paul e]

Appreciated.

[track.n.trail]

Originally Posted by skier219

Often times something like this may be due to the brake pads moving ever so slightly inside the calipers. If it happens the first time you brake in reverse but not the second time you brake in reverse, then it's a good suggestion this is the problem. If you alternated reverse, then forward, then reverse, you may hear the noise in both directions (but one of them may be easier to hear). If someone is standing outside of the car when this happens, they should easily be able to trace the noise to the offending wheel and brake. Normally this isn't a serious problem, but it could be indicative of a pad where the lining broke loose from the backer, or the pad guides/slides are worn. So I'd get it checked out if in doubt.

This, especially if you have the track handling/m-performance brakes. I always get this the first time I apply the brakes in reverse and have heard it's common/normal for these brake calipers.

[mlev]

Originally Posted by dotfiles

This, especially if you have the track handling/m-performance brakes. I always get this the first time I apply the brakes in reverse and have heard it's common/normal for these brake calipers.

I also recently had my pads and rotors changed and mine does this now. Clunk on reverse then clunk when switching back to drive, but then it stops. I have read that it's normal for many pads and am not worried about it.

[chenry]

Originally Posted by chenry

So I know this is an old thread, but figured better to resurrect vs starting a similar thread.

So my car (2017 340) has suffered from this condition since it was new, dealer could never duplicate the noise, thus it went unfixed. Until my most recent visit, the car is in due to a rock going through the radiator (yes another one of those) while there I was able to produce the "thunk" and SA sent me a message yesterday stating:

the foreman found an update to the driveshaft causing the clunk noise on your car! There is some hardware and loctite that needs to be ordered and it should be here in a couple days

Anyhoo maybe that will help someone if they are experiencing the same. I'll post a picture of the service order when I get it back

Here you go...