Hy 56 stepside, do you have a maintenance manual for your your truck? First you adjust the worm shaft preload, with the sector shaft adjuster screw backed off, and the steering box not connected to anything. Gently turn the steering wheel in one direction until it comes to a stop, now turn the steering wheel back one turn. Now tighten the worm shaft adjusting nut at the bottom of the steering box until there is no perceptable clearnace between the worm shaft and bearings, snug the lock nut. At this point you should check the amount of pull required to turn the wheel, if you have a fish weighing scale, attach it with a string to the outside edge of the steering wheel, it should require 1 1/2 lbs. of pull to move the wheel. Any less than that your worm bearings are too loose, any more, or if the turning is lumpy, then your bearings are too tight or you have damaged/incorrectly installed bearings. If you don't have a fish scale then just turn the wheel by hand, it should not be loose, it should not be too tight either, it should require a slight effort to turn and it should not be lumpy. If you can achieve that, then you can adjust the sector shaft clearance/preload. Gently rotate the steering wheel all the way until it stops, now turn it back in the other direction all the way to the other stop, counting the turns as you go. When you know how many turns it is lock to lock, gently turn it back precisely half the number of turns. This will put the box in the center of its travel [wheels straight ahead position], now you can turn the sector shaft adjusting screw on the side of the box, until there is no clearance between the sector shaft and the worm nut, snug the lock nut once you have that adjustment, now turn the wheel one turn in either direction, and using your scale, or just by feel turn the wheel back through the center of its travel, its required pull should now be 2 - 2 1/2lbs. or slightly more than the worm shaft bearing adjustment, it should be smooth, with no lumps. You can now fully assemble/install your steering box and go for a road test, there should be no clearance in the box at this point, good luck, and let us know how it went.
