Back when someone with the unmitigated gall to call himself a "mechanic" actually fixed things instead of just swapping parts, part of every front end alignment was checking and adjusting the center point preload (if necessary). All the procedure involves is disconnecting the pitman arm so nothing but the steering gear moves, and measuring the turning torque increase as the gear moves across the center point. The vast majority of the time, that adjustment completely eliminates any slack in the gear.
Jerry
