04 SD FX4 - How much play is acceptable on the drag link rod? The inner tie rods look good and have 20k on them. I can torque (rotate) the drag link rod by hand back and forth slightly. I can manually reproduce a metal 'clunk'.
My 'clunk' has returned when on bumpy roads and I think the drag link rod is part of the issue. The outer tie rods need to be replaced and this is also part of the problem.

 

Some rotational movement is ok as long as it takes effort to make it move, lateral movement is not ok. With the truck off and the key on ( so the steering wheel isn't locked )and wheels on the ground, have someone rotate the steering wheel left to right just enough to start moving the tires while you watch the steering linkage, there should be no lateral slop, meaning as soon as there is movement in the pitman arm everything else should move with it. I would also check the ball joints and track bar as well.