So, when I bought my SC the front struts were leaking. The car drove like the struts were shot. No big deal, I ordered a couple of struts (the most inexpensive I could find) and put them in. Car drove no different than before. So I moved up to the more expensive brand (KYB) made in Japan. I put install these and at first everything seems better. However when outside temperature rises above 75 ish, the car drives like there are no shock absorbers installed. Wheels bounce at every little bump and it feels worst at around 35ish MPH and around 70ish. It drives me crazy, cause summer is here and I can't enjoy the car. Please help.

 

Never noticed.

I've driven a few Mercedes SL's and the SC feels a lot like those. Just heavy cruising roadsters.

As smooth as these cars are on the highway...they are not very smooth on city surfaces and its by design. I don't think a new suspension will improve this feel that you speak of.

 

inspect the front and rear lower and upper control arm bushings if you haven't done so already. From the sounds of it, it sounds like those need replacing and replacing those would definitely stiffen up the ride.

 

after reading your post a few times, there's some questions that you can answer for us:

you said 2 front shocks were shot and leaking and you replaced them with KYB shocks?
what about the rear shocks? are they still there?

I believe the original shocks were Tokico for an '03 but don't know if that changed after that.

Could it be that you're running two different brand shocks with different compression rates
and one set is newer and the other set is older?

should you run the same brand for both fronts/rears and replace all 4 instead of running mixed sets?
also, what about the springs?
if you're running the mixed set, the springs could play a role in the bounce of the different branded shocks.

thanks...sam.

 

Here is my experience with my 2002 SC430 with 110k miles.

The front struts are shot and I just replaced them with KYB new struts. The ride is a little firmer and bouncier than before, which I think is due to the old worn/soft struts. Nothing too bad.

The rear OEM struts are still good. I got the new 2000 GS300 rear struts to change them out, but they don't fit on the rear TRD lowering springs (see my other thread on this) so I am still using the old ones now.