For over a year now car has been making a clunking noise under it everytime i roll over bumps. Still had warranty on car and took it in constantly to fix the problem but GM could never fix it. Ive had sway bar bushings and links replaced, struts and mounts replaced, steering gear replaced. and still same deal. At one point after sway bar and links were replaced went away for a lil while but came right back. Any suggestions what this could be?

 

control arm bushings

 

that^

or you could have something loose under there that nobody has caught yet. so check to see if all your hardware is tight.

 

Could be the intermediate steering shaft, ive replaced quite a few of those when i was working at the dealership..