Kistle

I am searching for an elusive clunk in my front suspension. It happens when swerving hard right to left (like you would do while warming up tires), and seems to be happening on both sides (or in the center and present when turning either direction). I have replaced the sway bar drop links, and just had the front struts rebuilt, neither of which showed any evidence of a problem.

When I get it back together, I am certain the clunk will still be there. I don't see any signs where the sway bar is hitting anything underneath, but I would like to exclude it from the investigation by simply removing it and seeing if the clunk is still present.

My question is, is there any harm/risk of driving and swerving hard (in a controlled test environment) with the front sway bar completely removed? I.e. is there any risk that the front body will roll so much that my tires will get into my fenders or other components and do damage? I will obviously be careful of unexpected oversteer, but as I said, I will do this in a safe, controlled environment. Just worried about mechanical or body damage from excessive body roll up front? Valid concern, or no?

Thanks in advance.

JA

993GT

highly doubt you will have any issue doing so, just watch for big oversteer

996FLT6

Does it clunk if hitting bumpy roads or it's just hard rt/lft turns? With a loose sway bar it clunks all the time. Mike

gman3280

+1 and check the end links too

AudiOn19s

No harm in doing this for a test. FYI the front bar on our car not as straight forward to pull as some other cars might be but as long as you have time to spare and understand the handling changes it will present to the car I don't see why not.

Kistle

Thanks guys. It only clunks on hard left to right swerving. It is rock solid at slow speeds over bumps, and at high speeds in a straight line. "Normal" cornering is smooth with no clunking.

I already replaced the sway bar drop links, as well as the center sway bar bushings, if that is what you mean by "end links".

I have pretty much had the sway bar out already when replacing the center bushings, so I don't think that will be a problem, but thanks for the good guidance AudiOn19s.

Any other thoughts on the cause of the clunking? I have gently pried around on all the control arm links and didn't see anything glaring. The car only has 28K miles on it, so after the sway bar and strut rebuild, I am trying to avoid a shotgun approach of randomly replacing parts to see if it goes away.

Thanks,

JA

AudiOn19s

My top mounts make some noise every now and then. They are a solid pressed monoball so when they develop a little play it's pretty noisy. Mine aren't bad enough that they bother me yet but it's an item I'll probably replace over the next winter.

Ray (rbahr) posted in one of his threads how to slightly modify the top mounts in order to be able to service them and just replace the bearing making it a much more economical fix.

Kistle

^^^Thanks for that. Yes, I inspected my top strut mounts carefully, and again, they are rock solid. Not even a tiny amount of play in the monoball bearing.

I am truly stumped on this one.

JA

serickson

I had a similar type clunk sound when rotating my steering wheel. It was explained to me by my shop that the spring becomes bound and does not freely rotate on the perch. I had read that this could be eliminated by allowing the spring to freely rotate by installing thrust bearings. I never did this but when I removed my OEM dampers I did notice that the bottom of the front springs had shown some mild evidence of wear from rubbing on the perches. Elephant Racing has Spring Seat Bearings. Not sure if these would work but it will give you an idea of what I am talking about. Good luck.

Steve

Kistle

^^^ Interesting. I will look into that. Thanks.

JA

blotto649

Do you feel it a fair amount in the wheel? Or is it primarily sound?

Kistle

Pretty sure I can feel it in the wheel. And it is significant. Almost feels like the top of the strut tower is moving a full inch on the side that is turning. That's about the only way I can describe it. Oddly, there is absolutely no evidence of an issue under ANY other circumstance. Cobblestone streets...tight, firm and quiet. Turning into a driveway over a curb....smooth and quiet. High speed runs down an on-ramp...accurate and predictable steering and handling of road imperfections.

Took it to a local racer/mechanic...a guy with EXTENSIVE experience with water cooled cars (both N/A and Turbo). He drove it and was able to easily reproduce the clunk. We put it up on his lift and he poked around. We only spent a total of about 30 minutes together on it (test drive and lift inspection), but he didn't see anything glaring. His recommendation, without looking into it deeper, was to replace the sway bar drop links and center bushing, and have the front struts refreshed. I have done that, but neither showed any sign of wear or issue (struts were put on a suspension dyno at Elephant Racing and no issues found). We went ahead and refreshed them anyway.

Stumped. I have not put the struts back on yet, but wanted to try the sway bar test that is the subject of this thread when I get it back together.

Appreciate all the feedback. Keep it coming, please.

JA

NaroEscape

I had a very similar issue with ours. Every right hand turn it would 'rattle' or 'creek'...not easy to explain, but at low to moderate speeds - like driving on back country roads, it sometimes sounded like the suspension was about to let go completely! It sounded like it was only on the right side.

We chased the sound for years, checked everything, checked all bushings...all seemed to be OK. Our GT3 is raised up a bit because its a street car and without it up a little higher, I can't get into/out of my driveway, so we thought maybe it was too high or something?? Tried everything...except disconnecting the sway bar and driving, like you are planning to do.

I have since disassociated myself with my mechanic (not because of this, but a much bigger issue) and went to a former Porsche dealer tech friend of mine. He recommended we try disconnecting the sway bar. We did it, drove around and the sound went away completely!!! He then said he thought it was set too stiff for the height and our street use, so he softened it one notch. BINGO!! no more noises. None. Been good for over a month now! In fact, the car even feels better to drive. Maybe the tight sway bar was binding up because of the raised ride height? Don't know, but I'm very happy now!!

Good luck!!

Kistle

Thanks Bob!

I actually have the sway bar completely off and am going to try the test today. Will post back with findings.

JA

Kistle

*** UPDATE ***

Does Rennlist have a traveling dunce cap, or "Walk of Shame" forum? If so, kindly direct me there immediately.

I bought this car last year 4th of July. Really have only done some fun runs with it, and not pushed it. Until one day in late winter (February?) I was following my buddy in his '09 C2S, and we were slaloming a bit as you would when "warming the tires" on cold tires/cold pavement. I heard and felt this significant clunk, left and right both sides.

Well, nearly 6 months later, and a lot of chasing my tail....apparently the P.O. had completely removed the battery hold-down clamp!! You can see where this is going! Well, last night, in a fit of desperation, I popped off the trim and tried to move the battery side to side. It moved a full two inches in either direction, banging up against the side of the battery tray on each push/pull.

Tonight, I fabricated a temporary metal bracket, bolted it down, and almost spun the car trying to re-create the clunk. Silent.

So, I am a monkey. I only post this to close the loop on what has been a frustrating journey for me, in the hopes that the next guy who is chasing something that he is sure is one thing, checks ALL the easy things first!

Thanks to Rennlist for the outstanding support and guidance, as always. I'll be over here in the corner with the pointy hat on!

JA