99, C2, Stock Suspension, 44k miles:

I have a strange problem with the front passenger side suspension. When going over a speed bump and or a pot hole it feels like the suspension is loose. This only happens in these two situations, when driving on a smooth road there is not a problem. There is zero vibration and the alignment is dead on. I had an indy shop (only services Porsche) take look at this. Everything checks out, bushings, sway bar, control arms, nothing loose or worn out. The shops conclusion is either the shock mount and or the shock it's self. Any one have any suggestion as to what else I can look for, and what the symptoms of a bad shock mount would be? And what to look for in a worn out shock mount. Thanks in advanced.

 

how about where the sway bar end links connect to the bar? have seen noises from the nuts not being tight enough.

 

The shock mounts can go bad, but mostly I've seen that with aftermarket springs. It will sound like a rattling noise when you hit bumps with that side.

 

Don't the aftermarket springs use the stock shock mounts? If so, why would they go bad with aftermarket springs?

 

Stiffer springs will stress the mount more than it was designed for. I kept ripping my upper mounts with PSS9 suspension and pretty heavy track use. They could get ripped with age and if they take a few hard hits. It's easy enough to check if that is what the problem is, you would be able to see the rubber torn.

 

interesting. i need to check mine. i have pss9 on my car, but they replaced US030. The PSS9 are much softer than the US030 (which was bone-jarring).

are you talking about looking at the top of the mount from inside the front trunk, or from inside the wheel well?

 

The strut is bolted to the upper mount. What you do, basically, is jack up the front of the car (both sides so the suspension droops), and remove the tie rod end. Remove the 3 nuts in the trunk holding the strut in the car. Be careful with the last one because you don't want the strut to just drop. After you lower it a little bit, throw a towel over the top of it to prevent body damage as you then lean down on the strut and get it past the fenderwell. Then you can take off the center nut(s) and take the top mount off. Inspect the rubber around the center for cracks.

The stock mount is probably fine for street use but for a track car the only solution I know of is to go to a monoball mount -- the problem with that is the monoballs will wear out on the street after 10k miles or so, but the bearing is easy enough to replace.

 

thanks! i just do street driving. i hear these are pretty cheap to buy, so i will probably just replace them while i am at it because if they aren't bad yet, they'll probably be bad soon since i am over 25K miles.

 

i have the same problem, but i have pss9s, i hear a zinging noise when swithching lanes on the freeway (caused by the lane divider bumps). months ago, i took it to an indy who torqued the top nut of the strut with a impact gun. the loose feeling and noise went away, but has come back!!!

uknowthis... dmingis's adivice sounds good, and im tuned in on ur solution. or try hitting the top bolt with an impact gun to c if it works.

keep us posted

 

I wouldn't torque the top bolt with an impact gun if I were you. It doesn't take much torque to strip the threads on the top of the piston shaft. If this happens, it means you will need a whole new strut. This has happened to me before on my BMW, and this part of the car is the same for almost any car.

 

Thanks to all who responded, I will let you know the outcome.

 

I took it upon myself to check some things out myself. I noticed that when the shop took a look at my car he put it on a lift but did not let the suspension drop. Since the noise was only noticeable when I went over a speedbumb (on the way down). I put the front on jack stands and had a look. I found that the left "drop link" had play in it (bolts were tight though). Ordered the set and will put on shortly. Thanks again to everyone. I'll let you know how it turns out.

 

c4s2nv..that zing noise is from the PSS9 springs winding up under compression and then releasing when unweighted. Very common issue. The reason the top nut tightening worked for a short while is that the springs were either rotated slightly or reseated differently until they moved and the noise came back. Bilstein sells slip rings that go under /on top of each set of springs for like $1.50 each, that prevents the springs from winding up in the first place. Of course, the struts have to be disassembled first to put them on...which sucks. PSS9s and 10 only come with one for the lower spring, the big blue plastic washer. This also can occur when the PSS( is adjusted to outside of its actual design range. Just because there are threads, doesn't mean it can be adjusted to there.

 

For those with older Pss9, there are some plastic washers available from Bilstein which remedy the shuttering noise/feeling. There is a thread on it here:

https://www.6speedonline.com/forums/...well-read.html

I just received my kit and am having my Indy install in about a week.

 

Finally received my new drop links (OEM). Installed them both (only took 25min each side!!). Went for the test drive, no more clunking! Thanks to all who replied!