I have a '99 GS4 and recently had a set of the original HKS Hiper coilovers installed. I set them to drop the car about 1" and left the damping at factory setting. My only other suspension mod at this time is a TRD STB. Running 17" inch wheels with 245/45s.

Since I've had the coilovers installed, the cars handles GREAT (Daizen sways are next), but I hear a very annoying clunking from the rear end (worse on the passenger side) when going over small bumps or irregular pavement. Strangely enough, large bumps are not as bad.

I know this could be a number of things, not neccessarily the coilovers because it might be highlighting something that existed before, but wasn't that noticeable until I lowered and stiffened up the suspension.

My list of possible causes are: bumpstops, end links, sway bar bushings. I've had the Toyota tech who did the install checking and he can't find the cause. Anything else that could be the cause?

Thanks!

 

What I could suggest is try to repace bushings...I have a problem like that in a previous car, I replaced everything in suspension and it was not a suspension problem. It was just oil missing in a door articulation cuze temperature was getting cold