Suspension Noise Public Service Announcement

[AMPowerJ]

I've struggled with clunking suspension noises with my KW HAS setup and now with my KW Clubsport coilovers for about a year. I've been reading many articles about coil bind, etc but that wasn't exactly the sound I was hearing and it was all the time over bumps, dips, etc. and it was getting worse. I ran across a suggestion somewhere to make sure you torque the sway bar tie rod to the strut with load on the suspension. I realized I hadn't done this with the installs so I pulled the front of the car up on race ramps today and tightened the nuts connecting the rod to the strut, obviously with the wheels still on and the suspension under load.

Voila! ... no more noise. Quiet as a church mouse.

So if you are having noise problems with your aftermarket suspension setups make sure you check this.

[dharo1]

[phantome46]

Really great help! Just given me the confidence to do my HAS suspension myself.

How did you load the sway bars? How much torque on the nuts?

Thanks

[x.shell]

Good tip.

[AMPowerJ]

Originally Posted by phantome46

Really great help! Just given me the confidence to do my HAS suspension myself.

How did you load the sway bars? How much torque on the nuts?

Thanks

Drove the car up on ramps. I couldn't get a proper torque wrench in the tight space but I would guess around 50 ft lbs.

[AV1977]

I have been struggling with the same noise. Thanks for the tip.

[Flying Low]

I'm not familiar with the KW Clubsport setup. I have clunking noises after installing camber plates but I have the stock sway bar and links and adaptive suspension. Does the KW Clubsport utilize the stock sway bar and links?
Thanks

[AMPowerJ]

Originally Posted by Flying Low

I'm not familiar with the KW Clubsport setup. I have clunking noises after installing camber plates but I have the stock sway bar and links and adaptive suspension. Does the KW Clubsport utilize the stock sway bar and links?
Thanks

Yes and since you had to disconnect the sway bar link from the OEM strut to install your camber plates you likely have this same problem.

[x.shell]

Originally Posted by Flying Low

I'm not familiar with the KW Clubsport setup. I have clunking noises after installing camber plates but I have the stock sway bar and links and adaptive suspension. Does the KW Clubsport utilize the stock sway bar and links?
Thanks

Every coilover set up will still utilize the sway bars and links. It is the link that attaches directly to strut body. It is the only bolt on the strut and easy to identify. If you are insecure about doing this, it might be a good idea to take it to a shop. It's literally a 30 second job.

[Flying Low]

I've had this area apart a couple of times. The upper link has a ball joint with a mounting base that has a male conical shape; not flat like earlier M3's. This conical base fits into a female conical mounting tab on the strut. So there really can't be any up and down sliding of the joint unless the ball joint nut is very loose. And of course, the ball joint itself is free to rotate 360 degrees within its socket. So I wonder if the after market struts have a link mounting tab with a female conical shape or if it is flat. I can't imagine any of the aftermarket struts having a flat mounting for the male conical ball joint, but if it did, then I can see where an improperly torqued ball joint nut might cause noise from up and down movement.

[x.shell]

Originally Posted by Flying Low

I've had this area apart a couple of times. The upper link has a ball joint with a mounting base that has a male conical shape; not flat like earlier M3's. This conical base fits into a female conical mounting tab on the strut. So there really can't be any up and down sliding of the joint unless the ball joint nut is very loose. And of course, the ball joint itself is free to rotate 360 degrees within its socket. So I wonder if the after market struts have a link mounting tab with a female conical shape or if it is flat. I can't imagine any of the aftermarket struts having a flat mounting for the male conical ball joint, but if it did, then I can see where an improperly torqued ball joint nut might cause noise from up and down movement.

This is a great observation.

I'm not 100% sure if this is the actual Clubsport strut for the F8X because suspension companies always release random press photos for new parts. However, I found this pic on an F80 KW thread and it shows the conical female tab for the strut.

[JamesGames]

You did this to the front and rear? I wonder if shops that install know about this procedure

[x.shell]

Originally Posted by JamesGames

You did this to the front and rear? I wonder if shops that install know about this procedure

No need for the rears. The sway links aren't directly connected to the damper housing like the front.

[BC_Garrett]

Originally Posted by Flying Low

I'm not familiar with the KW Clubsport setup. I have clunking noises after installing camber plates but I have the stock sway bar and links and adaptive suspension. Does the KW Clubsport utilize the stock sway bar and links?
Thanks

Double check your sway links, also since you did install camber plates double check the top center nut (the nut that bolts the plate to the shock shaft). We find improper torque at one of these two positions is the most common cause of clunks on most modern BMWs.

[Flying Low]

I have checked everything at least twice already. My next plan is to put the stock hats back in after my next track event at Miller Motorsport and see if the noise goes away. If noise doesn't go away, I'll start looking for something else. The noise almost seems like a resonate vibration that starts when driving over certain rough roadways. I don't get any noise over speed bumps or reflective lane bumpers. I talked to my local BMW service manager and he said there has been an issue with parking brake cable housings making noise on the M4 but I don't know if that noise would be transmitted far enough forward. I'm not absolutely sure that my noise is actually coming from the front suspension area.

[BC_Garrett]

maybe check it all one last time before Miller...thats a hell of a long and fast front straight for a car with unknown (possibly) suspension noises.

[AMPowerJ]

Originally Posted by BC_Garrett

Double check your sway links, also since you did install camber plates double check the top center nut (the nut that bolts the plate to the shock shaft). We find improper torque at one of these two positions is the most common cause of clunks on most modern BMWs.

Do you torque the bolts with the suspension under load? Again I think this is key.

[BC_Garrett]

Originally Posted by AMPowerJ

Do you torque the bolts with the suspension under load? Again I think this is key.

Shock shaft does not need to be under load, sway links should be torqued under load if possible.

[Who's on first]

So happy I came across this.

Noise is driving me bonkers, almost to the point of going back to stock/full coil-overs...

I'll be trying this ASAP!!!

Fingers crossed.

[x.shell]

Originally Posted by I hate picking user names

So happy I came across this.

Noise is driving me bonkers, almost to the point of going back to stock/full coil-overs...

I'll be trying this ASAP!!!

Fingers crossed.

Let us know how it turns out.

[Who's on first]

I'll ask this, for those in the know. I've never changed (had changed, for me) any suspension for any of my other vehicles.

The sound I'm hearing, to an inexperienced person sounds "hollow" , or almost like the spring is loose when hitting bumps.

Is this the sound that's being referred to in this thread?

Does that make sense?

[AMPowerJ]

Originally Posted by I hate picking user names

I'll ask this, for those in the know. I've never changed (had changed, for me) any suspension for any of my other vehicles.

The sound I'm hearing, to an inexperienced person sounds "hollow" , or almost like the spring is loose when hitting bumps.

Is this the sound that's being referred to in this thread?

Does that make sense?

Yeah. Try it with the suspension under load. You need some race ramps on a drive on 4-post lift. Mine it still quiet after doing this.