[mhowanic]

Car Info:
2017 BMW 440i GranCoupe - 69k miles

I recently started noticing a slight clunk coming from the drivers side front wheel. Yesterday during an oil change I noticed what looked like oil all over the inside of the drivers side rim and around the suspension. I could not source where it was coming from but am praying it is not from the actual strut.

With the front wheels off the ground if I grab the left front tire at 3 and 9 o clock position and wobble it i get a clunking noise. No noise if i grab it at 12 and 6 position. I tried the same on the passenger side and there were no noises.

I dug around the forum and it sounds like it could be either the thrust bushing inside the steering rack or the thrust arm or control arm bushing. Are control arm and thrust arm the same thing? The term seems to be used interchangeably.

My question is if it were the thrust bushing, would the clunking noise come from both sides when I shimmy each wheel back and fourth?

Curious if there is any sure fire way to know what to replace. I also did not find any DIY write up to change the thrust arms, if anyone can point me this way it would be appreciated.

I greatly appreciate any help.

[_ObiJon]

This may help: https://youtu.be/B86oDAfo8Tw?si=7QLrIKAAxwI5C09E

[mhowanic]

Originally Posted by _ObiJon

This may help: https://youtu.be/B86oDAfo8Tw?si=7QLrIKAAxwI5C09E

Thank you, That is very helpful. I think it’s safe to say the control arm bushing seems to be the cause of the noise. Will dig around a bit more and try to come to conclusion.

If anyone else has feedback I’d appreciate hearing it.

[AcJetjockey]

I recently had clunking sounds reversing and turning at the same time. Didn’t have much play in the 3-9 o’clock wiggle. But control arm Bushings were badly cracked. I replaced both control arms on each side and clunk now gone. Aside from a rusted ball joint nut the diy was pretty straight forward
There was a great DIY on FCPeuro website for the f30 front control arms that I found really useful. It even had torque specs for reinstalling nuts and bolts 🔩
Cheers

[mhowanic]

Originally Posted by AcJetjockey

I recently had clunking sounds reversing and turning at the same time. Didn’t have much play in the 3-9 o’clock wiggle. But control arm Bushings were badly cracked. I replaced both control arms on each side and clunk now gone. Aside from a rusted ball joint nut the diy was pretty straight forward
There was a great DIY on FCPeuro website for the f30 front control arms that I found really useful. It even had torque specs for reinstalling nuts and bolts 🔩
Cheers

Yeah I just got a chance to pop the wheel off and look around more. I couldn’t really see a whole lot as far as bad bushings. They looked alright. Were you able to see anything just by looking or was it only after taking the front control arms off that you could see the crack in the bushing.

On another note, i think the entire strut is bad. The oil that I was hoping was coming from a bushing is I’m pretty certain coming from the strut. So I’ll prob have to do that anyway.

If anyone seems anything outside of what I’m assuming is the strut let me know.

Thanks.

[AcJetjockey]

I was able to see cracks in the tension strut bushing at the front before I removed it. And when I removed it I could easily move that bushing. The shorter straight control arm wasn’t as bad but I replaced them both anyway. Car had 140km with original parts and it made a big difference.
I’d agree with you that it appears the strut is leaking though

[cnpetra]

strut may be leaking. I worked on mine (changed the strut top mount) this weekend and definitely your strut looks oily/dirty. Not sure it causes the clunking... Looks like you have the sport suspension, so strut is quite expensive, in the $500 range per piece. Top mount is $138. New boot definitely needed

As for the clunking, did you check the inner tie rod ends? Steering rack loose?

[mhowanic]

Originally Posted by cnpetra

strut may be leaking. I worked on mine (changed the strut top mount) this weekend and definitely your strut looks oily/dirty. Not sure it causes the clunking... Looks like you have the sport suspension, so strut is quite expensive, in the $500 range per piece. Top mount is $138. New boot definitely needed

As for the clunking, did you check the inner tie rod ends? Steering rack loose?

As I’ve been digging a little more it seems the leaking strut isn’t that abnormal with these cars. Seems like low mileage for a strut to go out but not sure.

I’ve also read that the clunking could possibly be the top mount. I guess there is a bearing that is mounted in rubber. That rubber wears out then the bearing wobbles around in the top mount. This also puts excess strain on the strut and I guess can cause the seals to blow.

From what I can tell the rod ends are tight, control arms look good as well. I read the steering rack has a bushing in it that goes bad over time which causes a separate clink when turning the steering wheel. This is also apparent in my car as a separate noise. I plan on replacing this at the same time.

Long story short. I have both front struts, springs and top mounts on order along with the little thrust bushing in the steering rack and special tool to replace it. I figure if one strut is had the other is soon to follow. Rears will be replaced shortly as well.

Question on the top mount, what lead you to replace that? Also, did you replace the (I believe it’s 5) bolts that hold it in place?

[cnpetra]

I replaced the top mount because of a clunking when going over slight bumps between 10-50 mph. It didn’t fixed it (but car is much quieter )

After that I ended up tightening the steering rack infamous three-hole bolt/thrust that I replaced 3 years ago. That reduced the clunking to bumps between 25-40 mph. I think steering rack is going bad in my case.

[cnpetra]

And yes i replaced the bolts (3 in my case), because I had to. The top mount was revisioned and it required bigger bolts. I think you can reuse the old ones. Also I needed a (special) long torx socket to lock the strut in place when tightening the nut that sits on top. I changed the boot, bump stopper, the rubber seating for spring, and the gasket as well.

[mhowanic]

I appreciate the feedback. Sounds like I may be on the right path. I plan to replace the entire assembly. Hopefully that fixes some of the clunk and quiets the car down a bit. I will also replace the thrust bushing thing in the steering rack as well.

Fingers crossed for refreshed ride and no clunking.