PSS9 front end noise

I've been driving around with the PSS9s installed for a week now. I noticed that when i hit a bump I hear a slight knock coming from the front. Is this normal? It sounds like a "clunk". It only happens when I'm cruising. The rears don't make any noise at all. I'll post pics soon. TIA

Check your front sway bar to start, might be binding at the mounts.

Not normal. Sometimes you might get a twanging sound at very low speed if you crank the steering wheel, but that should be it (this can be fixed as well).

I get the clunk in front too. It takes a big bump to cause it ie: speed bump or driveway curb. I'll check the swaybar and I'm curious about anyone else's experience with this.

I did not get 2 rubber washers with the kit, and from what I understand that was normal. Maybe I am missing something. I will check the sway bar as well. I do hear the twanging sound when i turn the wheel at low speeds. But there is a very distinct "clunk" that was not there when I had the stock setup. Thanks for the advice.

If I were you I would get the front end checked out...something is loose.

I have had this issue for 6 months since the PSS9's were installed..... After several trips back to the indy shop that did the install and being told that this was normal, I took the car somwhere else to have it looked at (noise getting louder). Come to find out that there are parts that need to be harvested from the stock mounts (Rotators) and installed with the PSS9 kit. Of course the PSS9 installation instructions don't refer to this... and guess what, mine are missing. Supposedly the spring is binding up when it's "loaded" and the wheel is turned.... This does makes some sense as the "noise" occurs when the springs is fully loaded and releases.. The car goes in next week... I'll let everyone know if this fixes the problem. I have pictures if my top mounts, if anyone wants them to compare to thiers PM me, I cannot figure out how to post pictures....

Can you PM the photos, or better yet.......post them here for reference. I figured that the two missing rubber washers might be causing this. I also understand that the US versions of the kit do not come with the two rubber washers (might minimize the noise?). This led me to believe that the kit could be installed w/out them. Otherwise, Bilstein would have included them. But I could be mistaken. Thanks.

Ask and ye shall receive ... Here are my "can't miss" instructions for uploading pics. BTW, these instructions have NEVER failed to help someone post their pics, so the pressure is on YOU to keep the "never fail" string going. All words shown in BOLD indicate buttons. If you are just doing a "Quick Reply" you will have to click on Go Advanced button. Then follow the steps below: Down below the part of the screen where you type the text and below the Submit Reply and the Preview Post and Spell Check buttons, there is a Miscellaneous Options section followed by an Attach Files section. In the Attach Files section, click on the Manage Attachments button. You will now get a pop-up window. There are 3 buttons Browse , Upload , and Close this Window . Click on the Browse button and now (in a new pop-up window) you can search on your PC to locate the pic you want to attach. Click on the name of the file you want and then click the Open button. Now click on the Upload button. After the file has been uploaded, you can click on Browse button and repeat the process to upload another pic or click on the Close this Window button. After you click on the Close this Window , you will be back to the original "message" screen. Your pic file should be listed just above the Manage Attachments button. If you are finished typing the text, you can click on the Submit Reply button and everyone will be able to see your great looking P-car! If your pics are too large, you can resize them with MS Paint, or PhotoShop software, or you can do it online at this web site. http://www.resize2mail.com/

My understanding is this...the instructs do NOT say to use the rubber washers from the stock suspension, however if you do use them you will get rid of the twanging sound at low speed when you crank the wheel (I did just had this done and it works). It is a different issue than a clunk when you hit a bump...that to me sounds like a loose mount.

pics uploaded thanks to gota911

Thats what mine looks like. While we are on this topic, I noticed that my rear right seems to have more travel than my rear left. I know this because there is more rubbing on the right. From the ground to the top of the fender, they measure the exact same height. Could it be the dampening is not working properly, or is there some difference in travel between each shock?

The dampening should not affect travel only the speed of recovery.

Reviving the thread..... GT3 camber plates and modified top perches......... No more noises and 3+ degress of camber on the front

Have you checked and ensured that the right torque was applied on the nuts of the top hats?

Actually, adjusting the spring plate up got rid of the noise completely.

I am getting nervous because I have a set of PSS9's that have been in my garage, waiting to be installed... Is there anything that I should be aware of? I was planning on just giving it to my mechanic to install, but now I am worried that I will have to make multiple visits to him to get it right, or I am concerned that my mechanic will not be able to get it right at all....

It's not that hard - just do it.

If your mechanic is one you trust for other items, this should be no problem for him, if not get a new mechanic.

I'm getting this twanging noise when turning the wheel at parking lot speeds when I'm backing up or pulling into a parking spot let's say. I talked to Dave Modderman (my SF PPI guy) and he said it's common on these units. Now you say Bilstein instructs us not to use the stock rubber washers, yet using them gets rid of the noise. Is it better to just accept this noise for what it is or is it the best of both worlds (no noise, safe PSS9 operation) to add these stock rubber washer pieces to the PSS9s? If I were to go ahead and add the rubber washers, how involved is this install and what parts am I looking for exactly? I'm getting an alignment done tomorrow and it would suck to have to realign after something like this.

I can't comment on whether the rubber washers will solve your problems. I will say I did not use them and have some occasional noise at extreme wheel angles. I am not worried about it. To answer your question, though: It's reasonably involved to put them back in. The front struts have to come out and they have to be dis-assembled and re-assembled. If you've not them apart before but more or less know what you're doing I'd allow 3-4 hours, your shop should charge you probably 1.5-2. You might be able to get away without re-aligning if you're very careful about re-install, but I wouldn't count on it.

crap i hate it when people don't do it right the first time around - thx bud so do I just need the rubber washers or do I need those steel plates too in the pic below?

Benjamin, You fix it by using the rubber washer. The Bilstein instructions are not very clear on this...but using the washer gets rid of the sound.

The top parts are the rubber washer...not the metal part.

cool so it's as simple as telling my tech to put these rubber washers back up top where the spring meets the upper plate? thx, ross!

I also called parts and they tell me there are two versions... a 3mm version and a 6mm version.... I take it i need the 6mm version for my '02 c4s?

here Take a good look. You need the item number 11 - Angular Contact Bearing part number 996 343 501 00 This is the thrust washer. It is an assembly of metal parts that allows the top half to rotate independent of the bottom half. This is what allows the entire strut assembly to rotate independent of the body. If you don't have this, the coils can be twisted, bind up, and then release causing the boing sound when turning at low speeds. If you want more info on thrust washers, you have to do a Google search. i haven't the time to put on a short course. I cannot say that a rubber ring will or will not help. I can say that you will have the problem if you don't use the thrust washer. That's what it's for. Cheers,

So wross is advising that I just get the rubber washers and I'm good, but the part 11 you've pointed me to is not the rubber washer, but yet another part that you refer to as the thrust washer. Am I understanding this correctly? And is the thrust washer part included in the PSS9 kit or is this an extra? Is it included in their instructions? I can't imagine that thousands of units of the PSS9s were installed without this part. I'm trying to reconcile wross's guidance with yours. It's confusing right now because one is saying rubber bushing, but the other is calling it a thrust washer that is an "assembly of metal parts" but that part 11 looks like like an assembly of metal parts.

Also this is more for wross... do I need part 10 (Support Ring) or 9 or (9) which is the sizing that my part guy asked me about. One being 3mm the other being 6.5mm. see my confusion here? Just trying to nail down what part I need to get rid of the twang noise. i don't even see part 11 in the pic a few posts above of the front struts on the car. The part pictures aren't in color and all look like donuts thus making it hard for me or anyone else to make a determination. my guess right now is that i need part 9 in 3mm or 6.5mm... well if true which one? looks like 10 is the round metal piece in the pic i posted. and number 11 per fred... i'm not even seeing that in the pic.

Trust me, it is a bit confusing and Bilstein doesn't make it any clearer. There were no thrust washers in my PSS9 kit. The instructions contain and exploded view of the PSS9 parts in assembled order and a note about reusing the OEM parts above a certain location on the exploded view. My installer installed the kit without several parts, including the thrust washers. I had the boing noise fro the get go. I then took it to another shop to have it properly corner balanced and aligned as the first shop did not get that right either. Upon driving my car into the second shop, the owner commented upon the boing noise and told me that I was probably missing the thrust washers. After acquiring and installing the thrust washers, everything has been fine for 2 years. I can't say what rubber ring or washer might have been reused. If in doubt, make a copy of the Porsche parts diagram and contact Bilstein of America. I believe they are in San Diego. You can get their contact info off of their website. Ask what Porsche parts are to be reused, which are discarded entirely, and which are replaced with the part supplied in the Bilstein kit. If you're working with a shop that has done these before, you should be alright. But to depend soley upon the poor instructions I received in my kit, an inexperiecend installer could easily make a mistake. Trust me on this, it took 3 attempts before my car was finally right. Cheers,

The sizing rings are the factory's means of slightly adjusting ride height. Your factory ride height has a +/- 10mm tolerance. Depending upon the characteristics of the individual spring, the height can vary. Porsche will use either of the two rings in order to get the assembled strut to the proper length when under load. Cheers,

Fred, fantastic talking with you over the phone. I learned a lot from our conversation and I hope to find a resolution to this with your help and that of wross' so that others may benefit from this bit of trail and error. I really do believe it is the thrust washers that I am missing and like you said from an engineering standpoint, this is the part that will resolve the binding issue. This is not to say that I have the rubber washer as it may well be a combination, but if I were to make a bet, I bet that I'm missing the thrust washers which cost quite a bit more than the rubber washers and for good reason since they have bearings in them. I will get a real look at my PSS9 strut tomorrow to assess the true as-is state of my setup on my C4Sizzle my nizzle.

The thrust bearing is a re-used part from the stock assembly. It is not supplied with the PSS9 kit. I'd say it's difficult but not impossible to neglect it in the re-assembly, but it's more likely that it's mis-installed or otherwise compromised in the replacement process. It should mount above the metal pieces shown in your post #22. As discussed you do not absolutely need the rubber pieces shown in that pic, but I'm pretty damn sure you need the metal ones. If they're not in there I suspect that a) that's the source of your trouble and b) your thrust bearings are demolished. I'm less sure about this second point (I'd have to crawl around under the car) but either way I'd be pretty mad at my mechanic. If you want something done right... If in fact those metal pieces have been left out, then what's happening is the spring is sitting in direct contact with the top mount plate (supporting mount), binding and sproinging away. When those metal pieces (support rings) are in, the spring sits there, and they are able to turn because they fit inside the thrust washers. I'm no expert, but...

Yea i see what you mean... my tc kline suspension on my m3 didn't reuse the rubber washer to where the spring itself meets the metal plate so i'm thinking it's the metal parts that are missing or not working like they should. i'm learning quite a bit more than i expected because of this tonging/twanging/boing nose. you can actually feel it thru the steering wheel. subtle, but alas noticeable. i'll find out more tomorrow.

To make this more confusing...When my PSS9s were first installed it was without the rubber part. When we later installed the rubber part, the boing went away. To be honest....as Fred says the Bilstein instructions are awful. I have been driving without that metal part (I still have it) it does not have bearings in it, just a metal ring and this would rub and make a grinding sound just like the springs of the PSS9 would???...Make sense? BTW, I am using FVD PSS9s, not the same as generic PSS9s.

doo bee do be dooo

I suspect those rubber pieces are now toast. If you look at the exploded drawing Fred linked to, you might see what I mean. Pretend for a moment you left out the rubber pieces but kept the metal ones, and the spring was sitting on them directly. When the spring wanted to turn (with steering), the spring and the metal piece would turn together, and since it surrounds the outer bearing it would rotate freely. Adding the rubber doesn't change this much but reduces noise and some vibration. To be clear: The metal pieces (support ring) are what allow the spring to match up with bearing. Leaving out the metal piece means that the spring sits against the rubber and instead of turning freely on the bearing the spring uses the rubbers compliance to allow travel. (The rubber ring may move somewhat.) You can see how this will fail. So, to reiterate my non-expert conclusion, you must have the thrust bearing and you must have the metal piece, but the rubber is optional.

great development/dessimination of info in this thread... i'll def keep this thread posted around my findings tomorrow. i completely understand what RamVA is stating above and what Fred talked to me about.

Update Colin at www.cantrellmotorsport.com let me know that the thrust washers were installed on the bottom (wtf) and the rubbers are missing. Ordered 2 of each. Thx, fellas.

I have the EXACT same problem. My springs are metal to metal with the alluminium puck at the top of the strut sitting on top of the spring. I'm visualising this very nice groove developing over time until the puck disintegrates and my spring shoots through the hood. ...perhaps I should quit drinking so much when I visualize? WROSS...speeddemon says hi. I was at Stevinson today and he brought you up.

Yeah, I understand what you say also, but do you (RamVA) have PSS9s and have you installed them...many times? Like my mechanic?

Since I only have one 996 I've only installed them once. As I've said more than once, I'm no expert. I would hazard, though, that installing them correctly once is more useful than installing them incorrectly many times. (I did have Funktion Auto look over my install before they aligned it. They tightened up the top nuts for me and proclaimed the job sufficient.) I'm not surprised it's making no noise with the rubber and without the metal disc/support, but I do think the thrust bearing is not being used (as a bearing), and that the rubber disc's compliance is what's quieting the car. That sounds like a bad situation, and if it were my car I'd remedy it - at the very least get the wheel off and take a look, see what you think. Take it in the spirit of trying to be helpful. Also, I was incorrect when I said earlier that I did not have the rubber in my car - I have both it and the metal disc/support. I have some occasional knocking noise but no sproinging. It is in the rear where I have left out the rubber. Details on how I did what I did are here: https://rennlist.com/forums/diy-996-1998-2003/303054-996-c2-pss9-install-how-to-diy.html

Update I had my trusty tech install the thrust washers, the rubber bushings and the result is ZERO noise, quiet as a mouse in the house. I can say with certainty that it's not just the rubbers, but also the thrust bearing. Big thx to Fred for steering me down the right path. Thx to wross for contributing and perhaps he himself got edified.

Hey benny...I guess you installed it both ways huh? With certainty...I doubt it...but as long as your happy...great news! Smurf blurf! BTW a turbo cab is different than a C4S...