Recently installed four Bilstein Sports on my C230. On the first one, was installing the top bolt with a socket, and after a couple of turns near the end, noticed that the shock piston had rotated from its original location. Because I was using a socket and not an open ended wrench, I don't know how much the piston rod turned. The instructions say not to let the piston rod turn, but doesn't explain why. Does anyone know?

The main reason I ask is that going over speed bumps there's noise from the front end that wasn't there before I installed the shocks, especially a loud thump from the right front wheel during rebound (coming down off the bump).

I'm going to check the front suspension again tomorrow, but I was curious if anyone knew whether the shock install could have had something to do with it.

Thanks!
Anthony

No problem. Bilstein cautions not to turn the rod because there is a very slight chance that it would unscrew internally from the damping piston.
Then the rod would be blown out forcefully by the internal gas pressure.
However, this would only happen if you were turning the wrench counter-clockwise to remove the shock bolt, not clockwise to tighten it.
Some types of shocks have a way to adjust the damping by clicking the rod CW and CCW, but not the Bilsteins.

DG

you are not supposed to twist the shaft. I have done it many times by accident and not noticed any damage, but I suppose there is the danger of damage....maybe you did.

I would suspect not getting everything tight enough first though.

Tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Sorry, to reply to your other question: if you get a rebound thump after installing new shocks, you should check the mounting at both ends. Make sure all the rubber spacers and washers are in the correct position, and the bolts are properly snugged. If you used a socket to snug the top nut, it's possible you didn't get it tight enough. A quick check is to compare the number of threads showing on left and right shocks. I usually snug the nuts down, then hold the shaft with a screwdriver in the slot on the top of the shaft, and make a final snug with a box-end wrench.

DG

Some Konis are adjusted by pushing the rod all the way into the body and turning it to make them harsher or softer. Whenever I used them I left them full soft - they still do a terrific job.

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1991 300 SEL
218,000 Km

"Xsbank's rules of mechanical intervention: Always go for the easiest solution first; 90% of what ails a gasoline engine is ignition; After that its all a WAG."

Thanks everyone for the replies! The info about the piston rod is definitely a relief, I was a little concerned about *something* adverse happening because of the rotated rod. Good to know also to be especially careful if I ever have to remove another set of shocks.

I'll have another look at things tomorrow, I've also been wondering if I hadn't gotten the bolts quite tight enough.

Perhaps it is the same explanation as I had when I replaced
the shocks. Top mount play, can be easily be seen when rocking
car up and down with the mount visible. Mine was fine.

Got another person to rock the wing up and down
while I was feeling the bottom mount point and
the mount points for the sway bar, which also
could be noise maker, for play.

Found that there was play in the bottom mount, that
caused the bold to "klunk" against the metal "hole" in
the shock. The Nm for the bottom mount is 100Nm (for
the W140), pretty much, but should really be so tight
that the metal "hole" in the shock is trapped to the mounting in the
bottom arm, so that the bolt and metal is trapped together (really
no good explanation, I know...)

And, the tightening should always be done at normal laden
state (wheels on the ground), not to stress the rubber.

br,
syljua

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1998 CL500 W140
1984 230E W123