More than likely you've lost a spacer (the notorious T-piece), or the plastic rollers that cover the bushings have worn down. Check the bolts to make sure you haven't accidentally loosened any, and also checked the frame incase you got a dogey machined pair with incorrectly shaped holes (hasn't happened in a long time but there's always the chance).
If it's clanking I doubt it would be the spring (it would be much more grindy and bouncing would feel odd), grab hold of your frame and wobble it around and try to determine where the movement is coming from and then take a look at that point.