[Brothy]

Hi guys, I’ve had a problem with what I can only describe as a rear end clunking sound, like something solid and metallic is wobbling/moving for several months now.
I’ve had 4 garages inspect the car with no luck in finding the problem (including bmw health check) and an MOT.
I can only describe the sound as someone swinging a hammer between two metallic objects.
Here’s what I’ve found that makes the sound worse and what Ive done so far to find the clunking

When the car is under load it’s clunking over uneven surfaces

When turning left while driving over uneven surfaces at slow speeds sounds worse

I’ve had new drop links, replaced the differential and upgraded the diff bushes

I’ve tried researching for months including forums with no luck, I will try to get a video tomorrow.

Any help or advice is greatly appreciated

2015 430D M Sport

[_ObiJon]

My first thought is the parking brake cable holder/bracket. It sits above the drive shaft, just in front of the diff. It's known to fail and there's metal sections on the cables that rattle around, hitting the underside of the tunnel.

[Polo08816]

Originally Posted by Brothy

Hi guys, I’ve had a problem with what I can only describe as a rear end clunking sound, like something solid and metallic is wobbling/moving for several months now.
I’ve had 4 garages inspect the car with no luck in finding the problem (including bmw health check) and an MOT.
I can only describe the sound as someone swinging a hammer between two metallic objects.
Here’s what I’ve found that makes the sound worse and what Ive done so far to find the clunking

When the car is under load it’s clunking over uneven surfaces

When turning left while driving over uneven surfaces at slow speeds sounds worse

I’ve had new drop links, replaced the differential and upgraded the diff bushes

I’ve tried researching for months including forums with no luck, I will try to get a video tomorrow.

Any help or advice is greatly appreciated

2015 430D M Sport

If it's clunking over uneven surfaces, my guess is going to be rear suspension (which could potential include control arms). I have 155,000 miles on my original rear suspension and the multi-link setups are pretty durable.

How many miles does your car have? How many miles are on the rear shocks/top hats?

[Brothy]

Originally Posted by _ObiJon

My first thought is the parking brake cable holder/bracket. It sits above the drive shaft, just in front of the diff. It's known to fail and there's metal sections on the cables that rattle around, hitting the underside of the tunnel.

Thanks for that I will give that a check the next time I can get the car up, can’t say I noticed anything when I replaced the diff but will double check

[Brothy]

Originally Posted by Polo08816

If it's clunking over uneven surfaces, my guess is going to be rear suspension (which could potential include control arms). I have 155,000 miles on my original rear suspension and the multi-link setups are pretty durable.

How many miles does your car have? How many miles are on the rear shocks/top hats?

The car has just over 114,000 miles, I’ve had the car just over 3 years so I can only assume the suspension is still from factory. I did have to replace the upper rear right control arm as I noticed during a tyre change it had bent backwards and was touching the shock !