I've repacked the slip-joint several times since I've owned the truck, without any resolve. Since it clunks when the TC locks, could it be a loose or bad TC?
mmmmmyeah, could be....
I'd think the TCC would either shudder or do something else.. I've heard of AOD OBS trucks banging the TCC on engagement, not the 5R's
Call BTS or Racer X and see if they can shed any light?