Ben in Plano, TX

Friends,

I took a long lunch hour today and removed the offending shock (for those who missed the original post it was groaning when going over speed bumps or fully extending) to try and determine the cause of the noise.

I believe my problem came as a result of improper installation of the 'hat' that sits between the spring and the OEM perch. There is a cutout that should receive a washer-like ridge where the hat fits down on the shock. I believe I managed to get the perch on and tightened without that washer-like ridge fully seating into it's cutout in the hat. So the shaft was not fully immobilized by the hat!! Thence the noise.

So... I repositioned the hat making sure that I felt it pop down over the washer-like ridge - tightened everything back up - and reinstalled. Now I do not hear any groaning noise from the shock.

While I had the perch of I did examine the issue of how the perch mounts to the 'hat'. Mr. Hargitt and Mr. Air are correct in their assessment of the contact area between the 'hat' and the perch. It is only a small rim of the perch that presses onto the flat top of the hat. This contact seems sub-optimal to me - but it looks as though one could place a couple of washers - possibly one metal and one rubber - in the void between the hat and the perch and substantially improve matters. When I have more time than a long lunch hour on my hands I may experiment and will post any findings to the list.

Thanks again for your advice and as usual - most of my problems stem from the 'nut behind the wheel'. <img src="graemlins/c.gif" border="0" alt="[ouch]" />

Ben

Suwipin

Thank you for the update Ben

I'll be installing my PSS-9 soon (next Monday) and I really appreciate your posts about this issue.

Ben in Plano, TX

My pleasure Pin,

I've learned much from the list and like to contribute back what small bits I can. Good luck with your install!

Ben <img src="graemlins/wave.gif" border="0" alt="[byebye]" />

Suwipin

Ben, do you think a monoball is a must or we can live with a couple of washers?

Thanx again Ben

Ben in Plano, TX

Pin,

I'm really no expert on the matter but...

It doesn't appear to me that there would be much opportunity for lateral movement of the hat against the OEM perch (assuming it's installed correctly ) so the main force to be borne is vertical, or along the axis of the shaft of the shock. So the question is whether the material of the OEM perch and the material of the hat can stand up to that force over time without deforming and failing. I saw no evidence of significant wear on the perch or on the hat - even with my botched initial installation - and both the perch and the hat seem to be pretty stout.

I'm going to DE the car weekend after next - I'll pull things apart after that and look for any signs of wear. But I doubt that it would be a problem under normal street/DE use. Seems that if there were a probable failure it would have happened to someone by now. I know that some on this board have had the setup for a while and DE'd on it as well.

Washers 'may' help out - and I gather from earlier posts that perhaps that is what some professional installers have done - but I won't know for sure until I try. Right now I'm just glad the groan is gone!

btw - I checked on the price of the perch should I have to replace it - It's a whoppin' $42 at the dealership.

Ben

Anir

Thanks, Ben, for the update. Much appreciated.

George A

Hey Ben,

It sounds like to like to tinker with your car as much as I do. I don't think I've ever met you but if you ever need any help with "tinkering", let me know and I would be more than happy to help you out.

Where in Plano do you live? A friend, who lives about a block away in Russel Creek, has a '96 993TT (I only have a C2) and we typically bleed brakes, replace pad, etc. If you are ever in the mood, send me an email.

George
george_abdalla@hotmail.com

Ben in Plano, TX

George,

Thanks - emailed you offline!

Ben

Richard C2S

Came across the same thing when I installed the PSS-9 several weeks ago. We used washers. I'm hoping to do a DE in two weeks and have already scheduled to take the car in after that to re-align and to check the "hat and perch" issue.

I was more concerned with the clearance (or lack thereof) between the sway bar and the lower suspension member. I would also prefer that the sway bar ends be more horizontal than they are.

Ben in Plano, TX

RAK,

While I had the shock out I lowered the sway bar drop link mount a few threads - I now have 4-5 mm clearance with the shock fully extended. I've had this darn thing apart so many times I can do it blindfolded in 30 minutes now.

Ben

Richard C2S

Ben,

The drop links that came with the PSS-9 kit are not threaded or adjustable as far as I can tell. Using the stock links wouldn't have changed anything.

It will be interesting to see how the car handles on the track.

Richard

Ben in Plano, TX

Richard,

Sorry for the confusion - I have the RS droplinks and the RS adjustable sways. When I said I lowered the sway bar drop link mount I meant the mounting point on the rear shock itself. The RS droplinks are longer than the ones that come with the PSS-9 kit and are curved for clearance.

<a href="http://boards.rennlist.com/upload/993_RS_rearbar.jpg" target="_blank">Pic of sway link</a>

Mine was not threaded down as far as it could go so I lowered it a few mm while I had the shock out.

Ben