Here's what I have done to my 1988 Grand Wagoneer (161,000 miles) to get rid of the approximately 2" of play in the steering wheel:
Replaced tie rod linkage at Pitman arm.
Replaced steering box with a new unit.
Replaced power steering pump (leaking).
Full front-end alignment.
I have been to two shops and they have both told me that the remaining tie rod joints are in good shape - tight. Both wheel bearings have been replaced recently.
I still have the 2" of play - I have tried tightening the allen screw on the new steering box (1/4" turn) and it made the steering more difficult to turn (stiffer), but the play remains. I have blocked the wheels, started the truck, and have found that the steering shaft turns the 2" of slop all the way to where it ties into the steering box. The pad where the steering shaft bolts to the steering box is tight. The U-joint in the steering shaft is tight when I grab both sides of it and turn in opposite directions.
What am I missing? I have got to find where the play is in the steering- it's a handfull out on the road!