Solving the clunk in the front suspension

[MikeWire]

Howdy guys, I'm looking for a little help here. I have had a clunk in my front suspension for quite some time, it's not that bad but it's annoying, and I want it gone. I've tried many solutions and none have solved it.

What I have done:
New 034 upper adjustable control arms (including alignments)
New S4 solid link TRE's
New control arm kit from FCP - full setup
New front sway bar bushings
New strut top bushing/bearing
All control arm bolts torqued to the correct spec, also torqued under proper load

Removed strut assemblies, I have the washer under the upper strut hat, and I added two additional washers on top to take up the slack, then used my impact to tighten.

SO...my strut assembly goes like this:

[TOP]
NUT
WASHER
WASHER
STRUT HAT
WASHER
||
||
STRUT BODY
[BOTTOM]

With all of that done, I cannot think of anything else that could be causing the clunk.

So, let's talk sub frame. I've heard of them developing cracks and causing a clunk, but I'm looking for someone who has had this issue.

Could I have a cracked/broken sub frame?
Where did the sub frame fail?
Are the fractures/cracks visible without removing the sub frame?

[vjborelli]

Engine/Snub/Transmission mounts?
Drive shaft CV joint?

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[MikeWire]

Engine/Snub/Transmission mounts?
Drive shaft CV joint?

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Snub mount is an Apikol, the cup adjusted properly to center.

The clunk is in the front, so transmission mount noise probably would not translate to the front. However, it's one part I have not changed or upgraded

Engine mounts are the 034 solid rubber mounts. Similar to the RS4 mounts. Bolts are tight, but I will double check them, good call.

Drive shaft, hmmmm....same noise as before and after I did a 5 speed swap, which meant I swapped out the entire rear drive shaft. Gonna have to say no on that one. And again, the noise is coming from the front.

Good ideas!

[seanf86]

they fail where the metal is folded over, the seam all the way around, if that is the case I have a 1.8 m/t subframe in good shape, could also be the subframe bushings separating. Did you do swaybar links? also check the torque of those and the bushings in the links.

[MikeWire]

they fail where the metal is folded over, the seam all the way around, if that is the case I have a 1.8 m/t subframe in good shape, could also be the subframe bushings separating. Did you do swaybar links? also check the torque of those and the bushings in the links.

Interesting, I'll need to get close up. Any specific area I should pay attention to? Inside/outside edges or front/back/sides?

Ohhh, subframe bushings, I never thought of those. Gotta see if I can get close up to those and see any imperfections or tears/separation.

Yes swaybar links were new with the FCP kit and didn't make a difference.

[seanf86]

Interesting, I'll need to get close up. Any specific area I should pay attention to? Inside/outside edges or front/back/sides?

Ohhh, subframe bushings, I never thought of those. Gotta see if I can get close up to those and see any imperfections or tears/separation.

Yes swaybar links were new with the FCP kit and didn't make a difference.

Check the inside edge all the way around, also look for rust holes on the top of the subframe in front of the rear bushings right where the subframe and firewall meet, I had a tennis ball sized hole in mine.

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[AudiTLC]

steering rack

[MikeWire]

Check the inside edge all the way around, also look for rust holes on the top of the subframe in front of the rear bushings right where the subframe and firewall meet, I had a tennis ball sized hole in mine.

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Will do, thank you sir.

steering rack

Steering rack was replaced just after I did the swap. I'll take a look at the bolts, if that's what you are referring to.

[Sam091990]

Will do, than you sir.



Steering rack was replaced just after I did the swap. I'll take a look at the bolts, if that's what you are referring to.

Seems like I'm not the only one. Had the clunk on OEM suspension, sport suspension, lowering springs, coilovers, and still have it with air ride. Also replaced my engine mounts with 034, transmission mount with 034, FCP control arms and swaybar links, APR snub mount, and upper strut bushing with 034. All the suspension bolts up front are tight, steering rack bolts are tight, and subframe bolts are tight. I literally gave up trying to find the problem...

[B6cool]

axles !!!!

[Coors]

Sway bar end links

[Coors]

Disconnect the end links and go for a drive see if the clunk goes away.

[MikeWire]

axles !!!!

Interesting thought. I took a video today with the car sationary on ramps, just grabbing the axle and moving it.

Disconnect the end links and go for a drive see if the clunk goes away.

Done. It helped, and I think an upgrade is in the future. But I still hear a slight clunking, so it wasn't all of the noise. Possibly the axles??

[1900gte]

same problem here.
I already have my car over 4 years and replaced almost everything and had the subframe welded.....still clucks at small potholes.

I once drove for a week without swaybar..no problem just limit your cornering speed. difference is surprisingly small.

I'll follow your thread to see if some new idea's come up.

[SJorge3442]

I too have a clunk I've been trying to pinpoint. I feel it when im going slow and I crank the wheel to the left real quick. I can feel it right on my gas pedal so I'm not sure what it could be. The Steering Rack bolts are gonna get checked this weekend. Other than that, I'm putting all new control arms in the next month along with shocks and shock mounts so we will see if it goes away. I sure hope so. I've been looking to do some autocross.

[JAYINH]

I had a clunk for a while, then while removing coilovers for winter I noticed my LOWER control arm bolt was not tightened all the way...doohhh. this solved my issue of a clunk at lower speeds, must have been me when I did the FCP arm kit.

[SJorge3442]

I had a clunk for a while, then while removing coilovers for winter I noticed my LOWER control arm bolt was not tightened all the way...doohhh. this solved my issue of a clunk at lower speeds, must have been me when I did the FCP arm kit.

Yeah I've been thinking it might be my worm arms causing the clunk. How are you FCP arms treating you? Those are what I am going with.

[EastTNPharmD]

Couldn't get your video to play, but I have a very similar clunk. I couldn't locate it, took it to my independent shop he put it on the lift and walked me to the front axles. They both a have a little play to them and that's the issue. Now the axles are still good, just a little give and that's where the noise is coming from.


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[gottaBdope]

Didn't read the whole things, but I saw front end noise and fcp kit. The bolts that came in my kit that connect the end links to the sway bar were too long. I got them down to torque and they looked fine, but apparently there was still gappage. A shop found that issue for me. Night and day difference.

[MikeWire]

Couldn't get your video to play, but I have a very similar clunk. I couldn't locate it, took it to my independent shop he put it on the lift and walked me to the front axles. They both a have a little play to them and that's the issue. Now the axles are still good, just a little give and that's where the noise is coming from.

Good info, my axles are still good as well, but the inner boots just recently tore. I've been looking into getting some Raxles, and I'll rebuild the set with the torn boots.

Didn't read the whole things, but I saw front end noise and fcp kit. The bolts that came in my kit that connect the end links to the sway bar were too long. I got them down to torque and they looked fine, but apparently there was still gappage. A shop found that issue for me. Night and day difference.

I'd like to get more detail from you on this. Those bolts are a little long, but they torqued down fine. Can you elaborate on what you mean by "gappage"? What exactly did the shop do?

[SJorge3442]

Good info, my axles are still good as well, but the inner boots just recently tore. I've been looking into getting some Raxles, and I'll rebuild the set with the torn boots.



I'd like to get more detail from you on this. Those bolts are a little long, but they torqued down fine. Can you elaborate on what you mean by "gappage"? What exactly did the shop do?

I would imagine he means that the bolts run out of threads and bottom out which isnt good since it doesnt fully tighten the arm. How this would be possible, IDK?

[vjborelli]

I would imagine he means that the bolts run out of threads and bottom out which isnt good since it doesnt fully tighten the arm. How this would be possible, IDK?

Bottom the bolt out inside the thread of the link. It will tighten down to spec since the bolt literally has no room to go any further, but there would be enough room for extra washers between the bolt and the bar.

IIRC, when I installed my option 3 FCP kit... The sway bar links did come with a washer to install with the bolts. I'll double check when I get out of work. I've had my fcp kit in for about 8k miles now, and no clunks or other sounds at all. I just installed my ST coils too.

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[MikeWire]

Bottom the bolt out inside the thread of the link. It will tighten down to spec since the bolt literally has no room to go any further, but there would be enough room for extra washers between the bolt and the bar.

IIRC, when I installed my option 3 FCP kit... The sway bar links did come with a washer to install with the bolts. I'll double check when I get out of work. I've had my fcp kit in for about 8k miles now, and no clunks or other sounds at all. I just installed my ST coils too.

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I will definitely look into this.

With my sway bar and end links removed, the clunks have definitely decreased, so I will add a couple of washers to the bolts and torque them back to spec. Interesting thing about the FCP kit, because that's exactly the same kit I bought and installed.

I took a close look at my subframe and I cannot see any problems with it. The bushings also look fully intact and good.

[MikeWire]

Update on the work here.

Added the sway bar back in, and threw a washer on the lower endlink bolts, and torqued to spec. Didn't help at all.

Checked and got a socket on the steering rack bolts to tighten them. Didn't help at all.

Double checked the torque on all four lower control arms. Didn't help at all.

Still clunky clunky clunk...

I figure it's either my Koni struts, H&R springs, or something in between causing the clunking, so I ordered a set of ST coilovers from Chris @ fifteen52.

That will be nice to have new suspension, but damn it sucks to have this clunk with no explanation!! I REALLY hope it's the issue.

[old guy]

Run a google on Audi A4 brake pad clunk or VW brake pad clunk. It's possible that your noise is coming from the brake pads. If so, this will cure it:

[MikeWire]

Thanks OG!! I'll check that out this weekend. Sounds like it's the outer pads, but could also be the inner by your picture.

[customa4]

You can pick up that brake quiet right from your local Auto Zone. That stuff is like glue.

[diagnosticator]

Yeah, brake pads. If you can drive over some bumps that provokes the clunking noise, then drive over the same bumps with the brakes lightly applied, and the clunking stops, confirms the pads are making the noise.

[old guy]

Thanks OG!! I'll check that out this weekend. Sounds like it's the outer pads, but could also be the inner by your picture.

That was just a generic picture that I lifted off of the 'net but I do use it on the inner and outer pads. It does a really good job eliminating clunks and squeals.

[SJorge3442]

I've been using the spray disc brake quiet for years now, but I'm convinced it doesnt do anything. I get a clunk from my brakes so I think using this glue version will help with that.

[MikeWire]

Well, not my brake pads. Stepping on the brakes makes no difference in the knock sound when going over the small bumps.

ST coilovers will be here sometime next week, I'm hoping that it's just worn out struts that are the issue.

[daverdfw]

So this may sound odd, but on my wives Volvo S60 she was getting a clunk whenever lifting off throttle, well low and behold the axle bolts on that model would get loose over time, right tightening them took the clunk away. I havent hard this issue on my A4, but it probably wouldn't hurt to check the torque on the front axle bolts.

[MikeWire]

So this may sound odd, but on my wives Volvo S60 she was getting a clunk whenever lifting off throttle, well low and behold the axle bolts on that model would get loose over time, right tightening them took the clunk away. I havent hard this issue on my A4, but it probably wouldn't hurt to check the torque on the front axle bolts.

Good idea, it's something to check for sure.

I also ordered Raxles to replace my CV joints. Should be here next week as well.

[Sam091990]

Good idea, it's something to check for sure.

I also ordered Raxles to replace my CV joints. Should be here next week as well.

I don't think the ST's will fix your issue, I've been through like 4 different suspension setups and still have a clunk. Make sure you don't put in the axles and coilovers at the same time, or you'll never figure out where the noise was coming from if it goes away . I'd also like to know if the axles fix the issue, mine is kinda getting to me.

[mk2rimar]

I don't think the ST's will fix your issue, I've been through like 4 different suspension setups and still have a clunk. Make sure you don't put in the axles and coilovers at the same time, or you'll never figure out where the noise was coming from if it goes away . I'd also like to know if the axles fix the issue, mine is kinda getting to me.

Actualy for me the st's fixed the clunk sound in the front....since i ad my other coilover set up the clunk was always there spent so much time and money to find the problem but no luck.... Last year i decided to replace my coilover set from a big spring coilover in the front to small with st's and guess wath that freakin clunk whent away for ever at any height droce the car for last summer all the way to winter and till today no more clunk.....good luck audiziner

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[87supraman]

Skimmed this thread, sorry if this was mentioned. Could it be the strut mount? My old ones were a good 1/4" squished compared to the new ones. Can't beat this price either.

http://www.europaparts.com/strut-mount-8e0412377c.html

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[maurizio]

interested in the solution here, having the a similar clunk.
Please let us know what fixed your issue.

[MikeWire]

Problem solved. Conclusion below...

Here's what I did...and here are the parts I replaced:



New axles from Marty @ Raxles:







Replaced both sides and took it for a spin, and still a knock. Sigh...well, the inner boots were torn and they needed replaced anyhow, so that's done.


And new ST coilover suspension:



While installing the ST's I noticed this mark on each of my lower control arms:



Oh man. Yeah, so I think the longer bolts that came with my FCP control arm kit may have been a bit long. When the strut compressed and the control arms flexed, it appears the bolt would hit the front of the rear control arm. I ended up cutting them down by about 1/2 inch, which is sufficient to secure the strut, and short enough to clear the control arm.

Torqued all the bolts to spec under load and went out for a drive FINALLY, no more knock knock...and the ST's ride much nicer than my H&R/Koni Yellow static setup.

Now to install the rear setup and it's all done.

Conclusion: The longer lower strut bolts were an issue, but were not all the problem. I suspect the entire problem was a combination of either a) worn out struts, and/or b) the strut nut was just not getting tight enough, although I used my air impact with two washers to tighten the sh*t out of it. Throw in the bolts hitting/interefering with the rear control arms, and those conditions would certainly cause knocks.

Key install tips:

1. Be sure to install the washer on the top of the strut rod, and underneath the strut cap
2. Install new strut bushings - they are cheap
3. Torque the strut nut to spec (40Nm IIRC) per the enclosed and very detailed install instructions (thank you KW/ST)
4. I used an additional lock washer under the strut nut - gives just a bit more insurance so the strut nut is tight and to spec

Can't think of anything else, but if anyone has anything to add, that would be good. Hopefully this thread will help someone out!!

[Sam091990]

Problem solved. Conclusion below...

Here's what I did...and here are the parts I replaced:



New axles from Marty @ Raxles:







Replaced both sides and took it for a spin, and still a knock. Sigh...well, the inner boots were torn and they needed replaced anyhow, so that's done.


And new ST coilover suspension:



While installing the ST's I noticed this mark on each of my lower control arms:



Oh man. Yeah, so I think the longer bolts that came with my FCP control arm kit may have been a bit long. When the strut compressed and the control arms flexed, it appears the bolt would hit the front of the rear control arm. I ended up cutting them down by about 1/2 inch, which is sufficient to secure the strut, and short enough to clear the control arm.

Torqued all the bolts to spec under load and went out for a drive FINALLY, no more knock knock...and the ST's ride much nicer than my H&R/Koni Yellow static setup.

Now to install the rear setup and it's all done.

Conclusion: The longer lower strut bolts were an issue, but were not all the problem. I suspect the entire problem was a combination of either a) worn out struts, and/or b) the strut nut was just not getting tight enough, although I used my air impact with two washers to tighten the sh*t out of it. Throw in the bolts hitting/interefering with the rear control arms, and those conditions would certainly cause knocks.

Key install tips:

1. Be sure to install the washer on the top of the strut rod, and underneath the strut cap
2. Install new strut bushings - they are cheap
3. Torque the strut nut to spec (40Nm IIRC) per the enclosed and very detailed install instructions (thank you KW/ST)
4. I used an additional lock washer under the strut nut - gives just a bit more insurance so the strut nut is tight and to spec

Can't think of anything else, but if anyone has anything to add, that would be good. Hopefully this thread will help someone out!!

Good to hear you got it fixed! Finally fixed mine as well... loose strut nut on mine