Joe, the large nut and lock ring at the bottom sets the bearing preload of the steering shaft (what the steering wheel is hooked to). You shouldn't be able to pull up on the wheel and get any movement. Tighten it as you would any wheel bearing, go tight and back off, then tight and back off, till you get a feel for where the lash ( play ) ends. You want it just tight enough the bearings make contact with the race.
Just to be clear, the above statement is not how the "book" says to adjust the bearing preload. Instead, the lash adjustment should be fully backed off (loose), pitman arm removed, steering wheel one turn off center (i think). Then, the bearing cap should be tightened so the scale reads between 1 and 1.5 pounds to move the steering wheel. Then the lash is adjusted...
