[liquidshadow22]

Hey guys,

So I've been trying to hunt down the clunk coming from hitting bumps. I've now replaced the sway bar, endlinks. I think it's coming from my M3 control arm bushings, which I made sure to tighten while the car was under load on ramps. Is this amount of play in the bushing normal???

I inspected the strut mounts, and I do not see any significant wear or play to account for the sound.

The sad part is that these control arms are only a 5 or 6 months old. I think I'm going to put the stock ones back in - what a PITA.

[PrematureApex]

Isn't that a ball joint vs. a bushing?

You think the arm moves like that in use?

Is there slop in the joint? From what I'm seeing, although it looks absurdly loose, the knock you're hearing is the ball joint reaching the end of its travel, which it wouldn't do in use. It isn't necessarily indicative of something wrong. Again, unless you're feeling slop.

If you're sure that is it though, how about pressing it out and tossing in a ploy in its place?

Cheap, easy, and no more noise.

[liquidshadow22]

Honestly, I'm not sure if it moves like that when the car hits bumps, but I'm out of ideas at this point. I don't feel slop in the joint but is it supposed to have this much freedom???

I don't know what else to do. I checked the struts mounts hoping this was the problem.

Any poly substitutes you know of that would fit?

[PrematureApex]

Originally Posted by liquidshadow22

Honestly, I'm not sure if it moves like that when the car hits bumps, but I'm out of ideas at this point. I don't feel slop in the joint but is it supposed to have this much freedom???

I don't know what else to do. I checked the struts mounts hoping this was the problem.

Any poly substitutes you know of that would fit?

For a bushing, not normal. But I'm pretty sure that's a ball joint in there. Is the knuckle end of the arm attached in that first vid? If so, yeah, that's not right.

There are a few poly options in there...I have Strongflex, but they're two weeks shipping from Poland. I'll see what else is out there, Powerflex probably.

But before you bail, let some one else chime in. Just keep in mind, that I think that's a ball joint, which has the freedom to move to the point where the inner section "hits" the outer. That's normal, but you shouldn't be seeing that movement in normal operation.

You sure your endlinks are tight?

[liquidshadow22]

the first video is the passenger side that I haven't taken apart or loosened.

100% the end links are tight and had a bmw master tech look it over, who thought it looked fine. he suggested strut mounts, but now that I know they are fine, I'm looking elsewhere.

[dailowill]

I have the same noise coming from my lower control arms. Are yours TRW or OE BMW M3 LCAs? I'm hearing an occasional clunking during slow speeds.

[PhaseP]

The movement on the videos seems okay to me. My xi wishbone has very similar bushing/ball joint to those and they move the same way with no noise.
You should be looking at the ball having free play inside the joint, not just rotation. Rotation is doing its think, free play allowing the ball to move inside the joint will cause noise.

[liquidshadow22]

TRW. It's super frustrating. Further inspection of stock vs the TRW M3 control arm joints demonstrates that there is play in the M3 one, but NO play in the stock one.

That is to say, the stock one is not designed for motion. See below. I can't be the only person with this problem.

http://s738.photobucket.com/user/liq...q54m7.jpg.html


Below is the KW street comfort with Vorshlag plates. I'm assuming this is totally normal. I didn't see any crack in the strut mount, NADA.

[dailowill]

I haven't got as far as you in eliminating other possible parts yet. Mine are also TRW and I don't remember the bushing being so easily moved when I first got it. I might try finding an ear chassis to rent; otherwise, I'm almost tempted to put the stock ones back on to eliminate the possibility.

Here's a video of my LCAs http://www.e90post.com/forums/showpo...70&postcount=1

[liquidshadow22]

Originally Posted by dailowill

I haven't got as far as you in eliminating other possible parts yet. Mine are also TRW and I don't remember the bushing being so easily moved when I first got it. I might try finding an ear chassis to rent; otherwise, I'm almost tempted to put the stock ones back on to eliminate the possibility.

Here's a video of my LCAs http://www.e90post.com/forums/showpo...70&postcount=1

SAME exact play! I mean, what baffles me is that there are so many others that have installed this without an issue.

[mojobmw_e90]

That bushing is shot.. Replace it.. You should not be able to move any suspension parts with your hand

[liquidshadow22]

Originally Posted by mojobmw_e90

That bushing is shot.. Replace it.. You should not be able to move any suspension parts with your hand

Except that I could also move it when it was brand new, from what I remember.

[PhaseP]

Originally Posted by liquidshadow22

Further inspection of stock vs the TRW M3 control arm joints demonstrates that there is play in the M3 one, but NO play in the stock one.

You are trying to compare stock rubber bushing to M3 ball joint bushing. They are different and will have different movement.

From what I can tell the M3 one's inside will look like the one in the middle of this picture, i.e. a spherical bearing:

http://8903e7f0897f2982f439-51d6683c...lay640x480.jpg

If you rotate it enough inside will hit the outside sphere, but when the arm is bolted in the suspension on both ends, it won't be rotating that much.

[mojobmw_e90]

Than u received a bad bushing.. How tight did you tighten the bolts. The harder u tighten it the less plays you should have unless the bushing is shot

[liquidshadow22]

Originally Posted by PhaseP

You are trying to compare stock rubber bushing to M3 ball joint bushing. They are different and will have different movement.

From what I can tell the M3 one's inside will look like the one in the middle of this picture, i.e. a spherical bearing:

http://8903e7f0897f2982f439-51d6683c...lay640x480.jpg

If you rotate it enough inside will hit the outside sphere, but when the arm is bolted in the suspension on both ends, it won't be rotating that much.

Agreed, it's a spherical bushing. While I get what you're saying, the first video I have is of the opposite side (passenger side) that I have not touched yet. So that side is definitely tightened and I can still get that amount of play with both ends fixed. Is it enough to create a clunk? I dunno, but I'm getting tired of just changing out parts chasing this problem down.

[PhaseP]

Originally Posted by dailowill

I haven't got as far as you in eliminating other possible parts yet. Mine are also TRW and I don't remember the bushing being so easily moved when I first got it. I might try finding an ear chassis to rent; otherwise, I'm almost tempted to put the stock ones back on to eliminate the possibility.

Here's a video of my LCAs http://www.e90post.com/forums/showpo...70&postcount=1

In your video was the other end of the arm bolted on to the steering knuckle? If it was, then yes it is a problem. With the arm in the suspension bolted it wouldn't be able to move that much to cause knocking. I can move my xi ball joint there, but not that much and so it won't make any noise. But it is not the ball joint there that limit that motion, it is the rest of the suspension. Something seems off.

[PhaseP]

Originally Posted by liquidshadow22

Agreed, it's a spherical bushing. While I get what you're saying, the first video I have is of the opposite side (passenger side) that I have not touched yet. So that side is definitely tightened and I can still get that amount of play with both ends fixed. Is it enough to create a clunk? I dunno, but I'm getting tired of just changing out parts chasing this problem down.

I see, then I think that is indicating a problem.

[liquidshadow22]

In this video, both ends are tightened (the other end is bolted to the steering knuckle and was tightened down with the car on ramps).

[liquidshadow22]

Quick update: After a long day of working on the car, I finally have reinstalled the stock control arms and regret ever having put in the m3 control arms. Waste of $400 + 2 different alignment jobs.

I guess you live and learn. The car is much quieter now.

[PrematureApex]

Originally Posted by liquidshadow22

Quick update: After a long day of working on the car, I finally have reinstalled the stock control arms and regret ever having put in the m3 control arms. Waste of $400 + 2 different alignment jobs.

I guess you live and learn. The car is much quieter now.

Not exactly fair. It's not like m3s clunk over bumps like that, nor many other people had your problem. You may have had a bad ball joint...which could happen on any car.

And 2 m3 control arms, don't cost $400.

[liquidshadow22]

Originally Posted by PrematureApex

Not exactly fair. It's not like m3s clunk over bumps like that, nor many other people had your problem. You may have had a bad ball joint...which could happen on any car.

And 2 m3 control arms, don't cost $400.

https://www.turnermotorsport.com/p-1...right-e82-e9x/

$390.75 - For all 4 and obviously due to the different lengths, I would imagine it's impossible to just install the upper 2 without the lowers. And maybe I did have a bad ball joint, but in either scenario, I went from a problem free stock setup to a noisey m3 set. And unfortunately, these control arms were noisey immediately after the install. What's worse about it is that I doubted it could be coming from them and ended up installing a bunch of new parts and wasting a lot of time before finally just realizing it was the control arms.

In a very objective sense, it was a waste of money for me. Maybe others haven't had the same bad luck.

[mojobmw_e90]

Going on 2yrs 30k on my m3 arms noise free 😎😎