Manual steering box

[Enoch]

With the pitman arm disconected from the center link there should be a maximum of 15 in LBS to turn the box. Now what you need to remember is that the 15 in LBS will only be right on and immediatly of of center.
You are correct you need to loosen the nut and tighten the screw (clockwise) which pushes down on the pitman shaft which has tapered teeth that engauge the teeth on the worm/sector gear.

What I would do to see if it is the steering box is to jack the front end up and let the tires hang free. Then grab the rag joint with your hand and rock it back and forth. You should be able to feel play in the box.

Rich