I just picked up some ground control coilovers with illumina's, the fronts went on fine, but the rears, when assembled had a gap between the top of the spring and the perch(correct term) it obviously compressed when i put the car back down. now the rear end clunks whenever i hit a bump. both sides simultaneously. What could be the cause of said clunking? and, that's the best way to describe the sound. Thanks.

Joe

 

On these bumps, are they big enough to unweight the back of the car and unseat the spring. Does the clunk sound the same as when the springs fell/squeezed into the perch after being off center a bit?

 

the problem is a problem associated with all sleeve type coilovers. They don't have preload which is why they uncompress when you lift the car off the ground. There really isn't a solution that I know of. Do you not have it lowered very much?

A full coilover will have preload and stay compressed when in the air...

like this

 

It's not lowered much. I still have stock 15's with 215/60's on there. I need to get some rims and tires, then Ill lower it. So, I pretty much have to just deal with it? It happens over most any bump, large or small.

 

You could make some kind of limit strap that will keep the spring under a little compression. Some coated wire rope from homey's depot and cable clamps work fine.

 

it won't be as bad if you lower it more. that way the pressure is on the shock for a longer period of time. Call up GC and see what they say about it