My hitch has developed some play at the point where it is pinned to the bed rails. It clunks when you stop and clunks when accelerating. Not bad, but enough to bother someone as anal as me. It seem...
Mine began to do that. I tried a wood wedge, broke; tried a metal washer, slipped out; tried rubber piece carved from a tire casing, slips out. I welded a bead - a ridge of metal - onto the hitch base, just enough to fill the gap, and the annoying clunk is gone.