Fixing the irritating clunk - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Hi –I am battling an irritating issue with my 98 986 and looking to find the root cause as mechanics have varying opinions. My vehicle makes a loud clunk as I pull out of my driveway which is at a slight slope, the same clunk happens when goes over bumps. 1. PPI was done at the dealership and they had mentioned the front shocks were toast. (I've changed every single part in the front suspension so everything is brand new) 2. Took it to one of the German mechanics I use after fixing the front suspension and he said it is the mounts, rear shocks and rear sway bar links (Changed all three mounts the clunk is still there) 3. Tried to get an opinion from another mechanic, he made me sit in the car and simply shake the steering wheel up and down, we reproduced the clunk at a lower pitch. Per him, this is the clunk I hear really loud over bumps. He also said there are rattles and noises from the rear suspension, but the clunk is coming from the steering column. I have searched the forum and not seeing much information on this fix. Tried a Google search, and I am coming up with is a rubber coupling tends to age or wear out on other cars, but nothing called out for the Porsche 986. Can someone please help me with this query? Looking to better understand what parts are potentially worn out in the steering column or is the only option might be to get an entire steering column which would seem highly unlikely. I would like to target the source of the clunk first to get it sorted, but do plan to get the rear suspension sorted as well.

Searched parts.com and found the attached image that outlines the parts. Also listing the front suspension parts that been changed. Front suspension parts changed thus far: 1) 2, Part# 4160500000 Control Arm & Ball Joint Assembly 2) 2, Part# 99634330102 Strut Bumper; Front; 3) 2, Part# 99634351505 Strut Bearing; Front Upper Bearing Plate 4) 2, Part# 99734301801 Shock Absorber Mount; Front Upper; 5) 2, Part# VN74623 Shock Absorber; Front; Sport 6) Sway Bar Drop Link (Front Left, Rear Left) 7) Sway Bar Drop Link (Front Right, Rear Right) 8) Tie Rod (Outer Section, Front Left Outer, Front Right Outer 9) Tie Rod (Inner Section, Front Left Inner, Front Right Inner) 10) Front Sway Bar Bushings I am sure someone else on the forum has experienced this issue so will wait for the experts to chime in.

You can't tell if it's coming from the steering wheel or the back of the car? My first thought would be the rear track arms. http://986forum.com/forums/performance-technical-chat/53590-rear-suspension-noise-over-tar-strips.html

Raj dont know about the steering column but i had clunks coming from the rear suspension. first and easiest thing to do was to replace the sway bar links(80$ all 4 from Pelican, not genuine Porsche) because everyone says they clunk. Didn't make a difference. i went to the next possible culprit which is the control arm link because i identified the sound as coming from right behind my left ear where the arm is connected to the chassis and that one bushing goes bad. 144$ from Pelican, again not genuine Porsche but did the job great! no more clunking! keep it in mind when doing the rear suspension. good luck! Cristian

Mine was same and from rear. This fixed it. PN 986 331 143 06 Trailing or control arm? Track arm is the tiny arm behind the wheel.

I am trying to change these control arms, but what a PITA to access the nut on the chassis side ! How did you do it? Slide your hand with a closed wrench through the small opening?

This did not seem difficult at all compared to the engine mount. You did remove the inner fender cover right ?

Quotes source post: 454082

Yes, I removed the cover for easier access. It doesn't seem that difficult indeed once you figure out where to locate the 18/21 mm wrenches. I have just spent 1 hour trying to loosen the bolts on the chassis but there is no way they will move, even if I soak them in WD40... The bolts on the wishbone came out easier... I put some more WD40 and will let it rest until tomorrow evening. I'll give it a try once I come back from work. Can you please guys let me know what is the best product to help loosening tough bolts? Thanks!

I was not trying to be condescending about the cover, from my personal use WD-40 is worthless....use PB Blaster or Kroil....I remember using a dead blow hammer a time or two to get things moving

I use all 1/2" drive and a big cheater. It will come out. Sorry to not see your post earlier.

Make sure the car is supported on the frame and no tension on the rear suspension or you will have a hard time getting the new one back in

Quotes source post: 454093

Don't worry, I didn't feel you were condescendant at all, I must have expressed myself the wrong way... I think I saw a PB Blaster on a shelf at work last night, going to borrow it tomorrow I tried the hammer as well, nothing would move so far. I hope the night will be my friend

Quotes source post: 454096

I removed the wheels and stands are under the 2 sides. Am I on the good path?

Yes you are, start the bolts on the frame first and leave them loose until you get the lower bolt through and connected.....then tighten

Gents, Many thanks for the input. I have placed the order for the rear control arm (L+R) with the rear sway bar links and sway bar bushings. Hoping this gets the issue sorted. I will report back in a couple of weeks once I have these installed. Have a good feeling that this might be the end of the irritating clunk.

The arms fixed mine. I tried the fix off Renlist by peening the bushings....worked just fine for almost a month and then back to normal noisy self. So a new set stopped the noise.

The quality of the rubber in the suspension parts in our cars (and other German brands for that matter) is sub par to put it nicely. I can get 15 years and 200k miles out of a Japanese control arm. Switching to harder materials like poly makes them last longer, but they're not nearly as quiet as a new rubber-based arm. I just swapped out most of the suspension in my 1997 Boxster again since buying it in 2004. I'm on my 3rd set of suspension parts now with only 35k miles on the car since purchase (it had 80k miles on it when I bought it). BTW, I replaced the trailing arms in back (long ones) just 2 years ago with Vertex poly ones and I still have an aluminum on steel squeak over bumps from behind my left shoulder. I guess I need to replace them AGAIN with rubber based ones. I think Houston's heat and humidity and crappy roads has a lot to do with longevity on my suspension parts. I REALLY HATE SQUEAKS AND RATTLES ... SO WHY DO I DRIVE AN OLD GERMAN CONVERTIBLE? I'm starting to wonder.

Quotes source post: 452037

Randall I'm curious if you used the 987 part number as Brad mentions it's better, but never stated why. Also healthservices posted these. Wonder if they would last longer?

Kram, I used the 986 parts numbers on my parts. Not sure why the 987's might be better... didn't know they fit my first year boxster. I've just removed the adjustable toe arms front and back from Top Speed along with my Ksport Koilovers in an attempt to make the ride nicer and get rid of rattles. Those orange adjustables are 1) HEAVY (made of steel) and 2) may well make a racket just as quickly as the factory style aluminum ones from Porsche. I'm done with aftermarket parts on my Boxster, but I don't blame others for giving them a try or even being happier with them than factory parts.

replaced rear control arms. clunking was back within six months. Heavy winter wheels and tires, rough roads... predictable. Gulf coast of Florida, maybe you'll have better luck. but hot and humid doesn't mix so much either.