Clunk, clunk and some more Clunk

Jayce,
Make sure the torque on your u-bolts is correct...I'd think that would be the cause. But, also check the tie rod ends and the bolts holding the springs to the frame.
Hmm, you're not in 4wd on the road when this happens are you? If so, take it out of 4wd and see if it happens...could be you're binding up the driveline...

Bogatyr

Jayce,
So you mean that the leaves don't line up with each other... I'd say you should be in the market for new springs shortly...are the clamps that hold the leaves together in place? With that second leaf not wrapping around it does sound that they are in pretty poor shape.

Now, since there is really only one adjustment you can make to the alignment (toe-in) there's no reason not to align it yourself. Just follow the procedure in the manual. If the outsides of your tires are wearing, and assuming that everything else is in order (which it sounds like your springs aren't the best)...oh...hmm, IIRC I was toed in too much and my insides were wearing...so I'd think that you might be toed out too much...it's been a while though so I might be mistaken...in any case, it's an easy fix.

Of course, if your tie rod ends are suspect, change those out before doing the alignment...

Bogatyr