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View Full Version : Front clunk/knocking noise. Confirmed diagnosis.



Dean
05-23-2011, 08:38 PM
http://tapatalk.com/mu/a6cd8bf1-38f0-9937.jpg

Well, I have had a front clunk/knock from the front of my car every since I put on my coil overs. It was on bumpy roads and around corners. I was almost 100 percent sure it was my sway bar end links that were causing the issue (I cheaped out and got duralast when I did my setup :( ).

Well my adjustable sway bar end links came in today (and they are pretty!) so I decided to put them on.

I took off the old duralasts and they seemed functional, however when i was removing one the top literaly snapped off of the shaft. :)N . Even though they seemed operational, I had proof they would have failed sooner than later. I placed the adjustable end links in and tightened them all up. after small adjustments (which still need to be fine tuned) took the car around the block to test out the end links.

MAN was I surprised! way better response in turns, feels like my car is on rails finally. I cannot believe how much I was missing out on. I was AMAZED at how much the handling improved from increased tension from the adjustable end links.

Needless to say, my fun was interrupted fairly quick when I heard the clunk again...This time louder and more crisp than before the swap of the end links.

Upon further investigation I determined that the top mounting point on the Coil Overs (Rokkor) is a slightly larger diameter than that of the end link connecting bolt. This is causing the connecting bolt to slide up an down within the hole causing the metal "boing/clunk/knock". The only other way I can describe the sound is if you pulled a sway bar back, and let it go into another piece of metal. The vibration of the impact is heard fairly loudly in the cabin, and even louder outside.

I hope to find some bushings this week to make all my troubles go away...

But for anyone else running rokkors, or anyone having this issue. Hopefully this helps!



Too...Lazy...To....Correct......Grammatical.....Er rors.




After some pondering I remembered I didn't not put any locktight on the threads. I'm going to attempt that tomorrow, in hopes it will stay tight. If I am lucky it will resolve my issues, but I kinda like the idea of bushings now...

danewilson77
05-24-2011, 04:14 AM
Thanks for the data Dean. Are you happy with the Rokkors? Maybe you could write up a product review for those as well. It would be appreciated.

Dean
05-24-2011, 08:09 AM
Will do, I will once I have some more time and repair all the little kinks with the setup so I can give a review with repairs.

billschusteriv
05-24-2011, 09:54 AM
Glad you were able to diagnose this one Dean. Did you get any pictures of the issues?

Dean
05-24-2011, 11:32 AM
No pictures, I will take some once I resolve the issue however!

TWong1200
06-12-2016, 08:02 PM
Bumping an old thread here but i have this exact issue since installing my KW's. I've taken apart my suspension an gazillion times and can't pinpoint what the issue is. I'm confident it's not my control arms. I've had a clunk for quite some time, happens when changing directions, turning the wheel left and right. Finally this morning, I decided to do a process of elimination. I installed all of my factory suspension back, including factory sway bar end links. Now running on stock suspension, I still get a clunk so i know it's not my coilovers.

The clunk no longer happens when turning left and right at slow speeds. I now just get the clunk at low to moderate speeds on bumps. I'm leaning towards sway bar bushings now as my FCABs, are brand new. Suspension is otherwise really tight.

Boy does the car ride great at stock height! It handles really well at stock height too!

Anyways, I'm thinking it's my sway bar bushings (not end links since both KW and factory units were installed and noise present). What's the recommended sway bar bushing out there? Stock? Poly?

09mageec
06-13-2016, 03:25 AM
To be honest, that sounds like control arm bushings. I wouldn't be so quick to eliminate them, as they do go. How many miles on the car (control arms), and is it driven in a seasoned environment?

slater
06-13-2016, 05:28 AM
could very well be a ball joint failing in one of the control arms.

09mageec
06-13-2016, 05:34 AM
could very well be a ball joint failing in one of the control arms.


+1 Check those CA's! The fact that the noise is apparent when turning the wheels...

TWong1200
06-13-2016, 06:57 AM
Thanks for the input, gentlemen. I've suspected the CA's but had a hard time convincing myself of them being the culprit for a couple of reasons:

- Prior to installing my suspension, no issues. I installed KW V1's including the sway bar end links, Z4M FCABs, top reinforcement plates.
- Noise started about less than 500 miles after I installed all of this.
- Noise is coming from both sides.

I'm just looking at this from a probability standpoint. No noise prior to the work. No noise until 500ish miles after the work. But what really gets me is that I have noise from BOTH sides. Having BOTH CA's go bad at the same time? Just hard for me to convince myself of that. Possible, but how probable?

But alas, that's why I come here to get other opinions, and I greatly appreciate the input.

The CA's are original and have 118k, on them now. Suspension worked mentioned above was done at 113k. So, the CA's do have mileage on them so perhaps you guys are right.

Thanks!

slater
06-13-2016, 07:24 AM
perhaps the added stress of the new suspension sent the failing ball joints over the edge? you can check them with a pickle fork easily enough. i actually need to check mine - mine are original with 145K miles - i have a new clunk, only over weird transitions (like pulling into a driveway with a bit of concrete in between the two surfaces), but i've got new tie rods and end links going in first.

09mageec
06-13-2016, 08:17 AM
perhaps the added stress of the new suspension sent the failing ball joints over the edge?
This was going to be my next response. +1

I know that this exact same thing happened to me a few thousand after installing my BC coils. Have yet to change them. There is another thread that ppl are posting in currently addressing the issue of wheel shimmy, with CA's being the culprit. I am also having wheel shimmy.

slater
06-13-2016, 08:53 AM
we should try to get a group buy going for lemförder front control arms... :)

TWong1200
06-13-2016, 09:28 AM
Thanks for the input everyone. I'll bite the bullet and get new arms. I'm also down for a group buy! How do we get one going?

slater
06-13-2016, 10:44 AM
Thanks for the input everyone. I'll bite the bullet and get new arms. I'm also down for a group buy! How do we get one going?

no idea, but i bet we could get at least 5 sets together pretty easily.

also... FCP has the TRW version for $112 shipped! that's pretty sweet. they are made in taiwan, whereas the lemförders are made in germany. but BMW does use TRW for OE parts...

09mageec
06-13-2016, 11:06 AM
German German....GERMAN! I may be in for a GB!

slater
06-13-2016, 11:31 AM
German German....GERMAN! I may be in for a GB!

hmmm. i know FCP has them, as does eEuroparts... both in CT. they might be willing to help.

TWong1200
06-15-2016, 03:06 PM
I've reached out to OEMBimmerParts.com for possible group buy. Their price now is very attractive as is. $158.98 per side.

https://www.oembimmerparts.com/BMW-Front-Control-Arm-ZHP-OEM-p/31122282121-122zhpoem.htm

I will let you all know if they are interested or not and what the terms and prices are.

TWong1200
06-16-2016, 09:03 AM
OEMBimmerParts has declined a group buy stating that their prices are already low, which is true. Lowest I've seen advertised anywhere!

BMWCurves
06-16-2016, 10:22 AM
OEMBimmerParts has declined a group buy stating that their prices are already low, which is true. Lowest I've seen advertised anywhere!

Thanks for checking. I'll have to look into them when the time comes for replacement control arms.

TWong1200
06-16-2016, 10:26 AM
Thanks for checking. I'll have to look into them when the time comes for replacement control arms.

Not a problem. I contacted FCP via their website to price match and they honored the pricing and matched! I just ordered from FCP. Can't beat their return policy!

BMWCurves
06-16-2016, 12:34 PM
Not a problem. I contacted FCP via their website to price match and they honored the pricing and matched! I just ordered from FCP. Can't beat their return policy!

Nicely done! I'll definitely be doing that when it comes time.

Oli77
06-18-2016, 01:56 PM
The CA's are original and have 118k, on them now. Suspension worked mentioned above was done at 113k. So, the CA's do have mileage on them so perhaps you guys are right.

My car has 105 K miles and I am on my 3rd set of OEM CA. Each time, you can tell from the obnoxious clunking.

TWong1200
06-18-2016, 09:29 PM
My car has 105 K miles and I am on my 3rd set of OEM CA. Each time, you can tell from the obnoxious clunking.

Third set at only 105? Wow!


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MtechJon
06-26-2016, 02:28 PM
Ive been getting a clunking noise when i go into my drive way and hit little dips in the street or speed bumps, was thinking to change my sway bar end links and sway bar bushings but maybe its my CA's