Steering Issues and Adjustments
I pulled the steering wheel off today, the PO had it positioned like 20 degrees off the straight track with the "T" logo upside down. So it's been messed with in the past but looks pretty original/good inside. If I remember the aftermarket tach was attached to the steering post with some kind of clamp, etc. I removed that stuff when I got the truck but I left everything aligned as it was for the time being, just to make sure something else I was ignorant to wasn't causing the offset. And the logo padded button was missing 1 (of 3) of the 4 x .5 mm long screws (with a point ground on the end) that Toyota says are no longer available.
Also experimented with the center arm today and realized if the adjustment is not backed off enough (a bit too tight) - one can easily create a situation where the steering will not right itself from a turn and is not even able to correct itself back into a straight tracking line - not good.
I would say I've got about 1.750 to 2.1 inches of play at the steering wheel related to your diagram, so I'll give this a shot ASAP. The only thing I'm wondering is if it would be better to have the front wheels off the ground to do the "full turn both ways" binding check?
August 10, 2012
Replaced all the rotted out seals on my tie rod ends, relay rod, etc. and greased everything up. Tightened up the drag link (per Miker's suggestion) at the pitman arm and also ordered a new replacement spring - the old one appears too compressed. Tightened the steering box gear play a little more. Steering seems better - still need to get in for an alignment check.
Got the new drag link spring from Toyota . . .
Old spring measures .920 overall - new spring is .960 in overall. Don't think the .040 will make much of a difference but I changed it anyway. Keeps the plug (cotter key) out a little anyway - so the plug is not as deep.