You have to adjust the worm gear preload first, then the sector shaft. Disconnect the pitman arm before making adjustments. Loosen the sector shaft adjustment lock nut, loosen the set screw so the sector shaft has no affect on worm gear preload measurements. Loosen the big (!) locknut on the worm gear preload nut (if it's caked with dirt etc. clean the threaded areas up first, it will make adjusting easier later) Then using a spanner (similar to what you use to set the bearing preload on an 8 3/4 differential case bearings) to adjust the preload on the worm gear bearings. The range is 1 1/4 to 3 inch lbs rotating (continuous torque as the input shaft is spun. Once the preload is in range, tighten the locknut while holding the adjuster to maintain the setting. Then you want to adjust the sector shaft setscrew to bring the total to 8 1/4 - 11 1/4 inch lbs of rotating torque required as the box moves through the center position. I'll see if I can find some pics to illustrate the procedure....
