First thing you need to do is remove your steering box, turn it upside down in a vise and swing the pitman shaft through the motion, lock to lock until the box is completely drained of fluid. then, find the center of the box and will likely find that the box has little or no "over centre", which means that it should have a high spot over the center. . Use a dial type inch lb torque wrench on the sector shaft(input end) and a 12pt socket to confirm this. .
First adjustment is to the sector worm gear. .
Mark the outer housing and the center adjuster nut at a location between the lock nut spaces.
Remove the lock nut and then torque the inner adjuster to approx 25" lb`s and make another mark in the housing, then measure back . 7 " on the outer diameter of the housing and make another mark if it is in a different spot than the origional mark on the housing. Back the inner adjusting nut till the mark lines up with this new mark on the housing. Install the lock nut making sure that the inner nut does not move from its new position.
Next, with the torque wrench again on the sector shaft, recheck for over center.
You will notice that most boxes have approx. 5"lb`s of rolling torque through the motion of the box. The center of the box requires approx 6"lb`s extra rolling torque than the rest of the box. . This can be obtained by adjusting the allen wrench bolt on the top of the box. I would suggest to adjust this at 1/8 turn intervals till the required over center is obtained. . (in my exp. , no more than 6"lb`s extra rolling torque should be used. . Don`t go by "if a little bit`s good, a whole lot is better")
Re install your box and install a synthetic style p/s fluid or ATF4 if you live in a colder climate or normal p/s fluid if in a warmer climate... This helps for cavitation in the winter time which causes no p/s or pwr brakes when first started in the winter
Test drive the truck and get the steering wheel center by adjusting the link near the steering box. .
ENJOY... ... ... ...
Garth
P. S. The adjustment seems to work better if the steering box is good and warm before the adjustments. . You will adso likely get a moan from the box for about a week till all the air works it`s way out. . And, some boxes have loose bolts on the top of the box, so, I always tight en them before any adjustments are made. .