Original post by: Corbin ,
I had the same issue with my '07 Century. Mirrors vibrated very bad from the factory at idle. I even drove another Century on the lot after I got mine to try to find out if it was just my truck. It wasn't. I changed the damper an added the balancer at 500,000. I only saw a small improvement at idle and more at highway speed. I thought that was all I could do because I'd had the motor mounts and clutch (and all parts) checked numerous times to no avail. Then while chasing an oil leak that required pulling the trans I found the clutch had about 30% left on it at 614,000. So I had the flywheel resurfaced and the clutch replaced. Aaaand guess what? Mirrors are now steady at idle. So, not sure if it was the flywheel not being surfaced right from the factory, or if the clutch was messed up. Sorry to say you might have to wait until you change your clutch again to find out if there really is a problem with it. Good luck.