Thanks for the reply.

I too was extremely surprised, but this started to happen immediately after cranking torsion bars. After the first adjustment, I took the xterra up and down a mountain logging trail to get it to settle, and on the first rut heard a clunk. Since everything is too new to have this type of problem, I have suspected the shock as the most likely culprit. Annoying as hell - something's gotta be done.