[davepl]

I find it's almost never the box unless the suspension has already been rebuilt, as the other parts wear first. I've never had luck trying to take any slop out with the backlash or whatever that adjustment is.

Ball joints, tie rod ends, centerlink, pitman arm, idler arm. You can either inspect and determine which need to be replaced, or you could just replace them all if its time (like over 70,000 miles in a 1/2 ton for the ball joints, around 100K for the various other parts).

If a rag joint starts to go, usually due to oil or other contaminants, it can also add slop.

To determine which:

I would put it up on jackstands. Grab the tire at 9 and 3 oclock. Rotate back and forth lightly. If the other wheel doesn't move with it like it's all one unit, I believe that rules out the steering box. If, however, they operate in unison with no slop then it could be the box or the rag joint. This little exercise is really to tell you if what you're feeling in the wheel is before or after the steering box.