I need some help from fellow Do-It-Yourselfers. I just received the Bilstein heavy duty (sport) shocks and H&R springs for my '93 C2, and have a question about the rubber bumper. The spring instructions say trim off 3/4 of an inch before installing. But how do I install the bumper on the new shock? The replacement Bilstein shaft is much larger in diameter than the original one. Where do I put the rubber bumper?? It would be smashed flat if I put it on the top of the shaft.

Right now, the plastic accordion boot snaps over the top of the shaft, and there is only about 1/2" of shaft left, which is where the top spring cover goes. It appears like there is no room for the rubber bumper. Anyone out there face the same situation, and what did you do about it?

Thanks,
Steve

 

Steve,
If the shaft is about as big as the strut housing (about 40 mm in diameter) then you have a RSR type strut. The shock is actually an insert which slides inside the strut tube, and attaches to the car. The shaft which you usally see is inside the strut body and attaches to the bottom of the strut. Look at the bottom and see if you see the threaded shaft and the nut. Some people have put the bumper on the shaft inside the strut.
Hopefully, one of the experts will chime in, who know more than I do and can really give you advise.

 

Thanks, Dennis.

Yes, my shock does have the nut visible at the bottom of the assembly. Does that mean I should take it apart, and put the rubber bumper on the shaft on the inside of the assembly?

Steve

 

Steve:
Not sure about RSR struts, but the standard Bilstein front struts have internal bumpers and do not require the stock Porsche bumper.
Bob 1989 C4

 

Thanks Bob.

I will check that out and see what I find.

Steve

 

I have recently fitted the same setup and did not use any external bump stop rubbers on the front. To date this set up has been very good. The only thing I would change is that I left the spring seat adjustment nuts at the bottom of their thread which makes the car quite low in the front. I would recommend lifting these 15 - 20 mm (approx mid way up the threaded section)

 

its the other way round isnt it ??
wind the collars up to compress the spring and lower the car

 

With the car sitting on the ground the springs are compressed and supporting the weight of the vehicle. If you wind up the nuts you lift the spring and therefore the vehicle up. The springs do not compress any more as the top mount is free to move and moves the same amount as the nut adjustment.

 

Thanks to all for the info. I contacted Bilstein directly at 800-537-1085 and they were quite helpful. They even have a Customer Service Dept. I was informed that yes indeed, the shock is upside down, and there is a bumper stop inside already. So you were right, Bob. And thanks, Stephen, I will start with the adjustment in the middle.

Steve