[bf360]

I have been having an ongoing issue that I have not been able to diagnose with my 2016 X3 35i, whenever I brake hard enough for the weight to transfer to the front I get a vibration that can be felt in the rear/brake pedal. It normally only happens above 50-60 mph and only if I hit the brakes hard enough to induce brake dive.

Here are the things I have checked/replaced:

New pads and rotors
Alignment
New Tires

None of these have even affected the vibration that can be felt mostly in the pedal but in the rear of the car. I do not get a steering wheel vibration and the harder the brake dive the harsher the vibration. Any ideas what could be causing this or where to look next?

[bmwPower99]

Originally Posted by bf360

I have been having an ongoing issue that I have not been able to diagnose with my 2016 X3 35i, whenever I brake hard enough for the weight to transfer to the front I get a vibration that can be felt in the rear/brake pedal. It normally only happens above 50-60 mph and only if I hit the brakes hard enough to induce brake dive.

Here are the things I have checked/replaced:

New pads and rotors
Alignment
New Tires

None of these have even affected the vibration that can be felt mostly in the pedal but in the rear of the car. I do not get a steering wheel vibration and the harder the brake dive the harsher the vibration. Any ideas what could be causing this or where to look next?

Wheels slightly bent out of shape, sometimes shops don't pick this up properly or just do a shitty job of balancing the wheels!
Warped wheel hub which the rotor attaches to.
Rear bushes / suspension need replacing.
Your ABS is kicking in?
Drive shaft/ diff issues - Does it happen when braking in neutral if the ZF even allows you to get into Neutral .
Did some kind of accident damage or other work initiate the vibration? have you always had it?


My money is on worn suspension components.
Also try swapping wheels back to front just to rule out any wheel issues that were missed by the tyre shop.

[Msportdriver1]

have you checked the front brakes at all??

[bmwPower99]

try getting your wheels Hunter Road Force balanced
https://www.hunter.com/find-equipment/

[Ol' Fart]

As someone else mentioned, sounds like ABS kicking in. If you have never experienced it, it can be unnerving the first few times. It will clearly lead you to believe there is something wrong.

[bf360]

Originally Posted by Ol' Fart

As someone else mentioned, sounds like ABS kicking in. If you have never experienced it, it can be unnerving the first few times. It will clearly lead you to believe there is something wrong.

I considered it being ABS, but it happens every time I brake at speed and varies from mild to aggressive depending on how hard I brake. I have felt ABS before and unless the ABS is broken this is not it.

[bf360]

Originally Posted by bmwPower99

Wheels slightly bent out of shape, sometimes shops don't pick this up properly or just do a shitty job of balancing the wheels!
Warped wheel hub which the rotor attaches to.
Rear bushes / suspension need replacing.
Your ABS is kicking in?
Drive shaft/ diff issues - Does it happen when braking in neutral if the ZF even allows you to get into Neutral .
Did some kind of accident damage or other work initiate the vibration? have you always had it?


My money is on worn suspension components.
Also try swapping wheels back to front just to rule out any wheel issues that were missed by the tyre shop.

The vibration stayed exactly the same after new tires and balance, not even a slight change so my guess is not on a balance issue unless somehow they were balanced imperfectly before and after.

No damage ever, no accidents, and there was a bent wheel that was repaired and straightened last year but was fine for 10k+ miles after that.

Still does it when putting it in neutral, tried turning off all traction control and putting it in neutral and will still judder/vibrate the rear.


Any idea where to look for a worn suspension bushing? Any more likely to fail first that might be worth replacing?

[bmwPower99]

Originally Posted by bf360

The vibration stayed exactly the same after new tires and balance, not even a slight change so my guess is not on a balance issue unless somehow they were balanced imperfectly before and after.

No damage ever, no accidents, and there was a bent wheel that was repaired and straightened last year but was fine for 10k+ miles after that.

Still does it when putting it in neutral, tried turning off all traction control and putting it in neutral and will still judder/vibrate the rear.


Any idea where to look for a worn suspension bushing? Any more likely to fail first that might be worth replacing?

Normally just jack up a wheel and shake it while holding at 3 and 9 and then 12 and 6 o'clock. But I've never found this to be enough, a big pry bar always helps levering against individual bushes looking for movement. The first thing I would check would be the Guibo/driveshafts .

[bf360]

Wasn't able to find anything noticeably worn or loose, and the vibration is still there. It looks like its going to BMW to diagnose soon.