This is a brief recount of a thread on 6speedonline. A poster, yellowbmr, stated:

"Clunking from front at slow speed anyone? Do you have PSS9? Well read on...

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I started to notice the infamous clunk (those who have PSS9) from the front of the car last year. It was only noticeable at slow speeds <2-3 mph. I took the car to dealer to inspect the end links and they said those are tight as hell. The car was under warranty, so it would have been considered a warranty item, but they didn't see anything wrong with them.
The noise radiated through the steering and it felt like something is broken in the front. So I lived with the noise but up to a month ago I coulndn't take it. I researched forums and came up to a thread that mentioend the same symptoms as me.

To make the story short, found out on the new PSS9 kits, they come with new washers that eliminate the clunking. These washers were not available on the PSS9's that were bought few years back, but Bielstin has a kit that eliminates the noise for those. The kit is free from Bielstin but the labor is not covered. Lucent had a kit in stock and installed it for me. The noise is gone.
While they had the coilovers out, they also cleaned the dust/grease/sand from the top of the coilover, washed the brackets with circuit cleaner, re-applied grease and installed the new kit for me. I paid around 2-3 hours of labor, but it was well worth it."

He has not come back with any info, yet, so I made a call to a guy at Bilstein that has been very elpful to me in the past. Here is what I found out and posted:

OK, I got the answer. Well, maybe not THE answer, but AN answer. Bilstein in NC and CA have no idea about any free kit to fix the clunk. If the OP has any info, that would be great. HOWEVER, the equivalent solution is pretty cheap. If you looked at your original PSS9/10, the bottom, helper spring, rides on top of a large blue plastic washer, between the spring and the adjustable spring perch. You can order another one for the top of the front helper spring, (2 total needed) 60mm, part number E4-XK6-Z002A00 for $1.50 each. You can also order 70mm ones for the top main springs, front & rear, and the rear helper springs, part number E4-XK6-Z002A01, 10 required, same price. However, the lip on the top spring cup, under the RSM, is pretty shallow, and reducing it by 1.5mm might not be too good an idea. Also, how much clunking comes form the rear, anyway? If you install them, order 2 new main top nuts, as the nylon lock ones are one use only. All the parts form Bilstein, 12 washers and 2 nuts, was $25 shipped. Naturally. as the washers are 1.5mm thick, if you add 3 new ones, then the car is raised 4.5mm higher than the designed range, and that must be accounted for in keeping it within Bilsteins lowering limits. Bilstein east coast is 1-800-745-4636, ask for Parts or Kieth Robertson. They ship out of CA, so you might also want to call CA direct.

Hope others with PSS9/10s find this helpful.

 

good info - maybe post this on renntech too

 

I am curious where you adjusted the threaded collor too ?

My 993 C4S calls for between 120mm and 140mm.

My new (not installed PSS10 yet kit) has one blue large washer on the bottom of the lower coil.

Thanks,
Patrick