I'm not Bill, but here's the way I learned to check steering centering and free play over 50 years ago. It still works.
The adjustment is sensitive enough that it cannot be done with the drag link connected to the Pitman arm, so disconnect one end or the other. Turn the steering wheel lock to lock, and count the turns. Return the wheel to exactly halfway of its travel. Now, turn the wheel 90 degrees off the center point and attach an inch-lb. torque wrench to the center nut of the steering wheel. Turn the wheel through center, and observe any torque change as it goes over center. Adjust the sector preload adjuster on the opposite side of the steering gear from the Pitman arm until the turning torque increases 10 in/lbs. as the gear rocks over center. At this point, there should be zero free play with the steering gear centered. Reconnect the Pitman arm and look for free movement at both ends of the Pitman arm and the tie rod ends. Also check for movement of the spindles at the top and bottom king pin bushings.
Always begin checking for steering slack by adjusting the sector preload. DO NOT SKIP THIS STEP!
Jerry
