Steering Gear Adjustments
The recirculating ball gear box and the rack and pinion steering systems are the two prominent steering gears found on vehicles today. The recirculating ball gear box is found on parallelogram steering linkage systems. These gear boxes will sometimes require adjustment if the steering becomes sloppy or loose. Always check other items like the steering shaft u-joints and couplings, loose mounting bolts, or steering linkage before making any steering gear adjustments.
There are two adjustments that should be checked and set to specifications if necessary. The measurements should be checked with an inch pound torque wrench before any adjustments are made. The first adjustment is the input shaft / worm gear thrust bearing preload. The term input shaft and worm shaft indicate the same part just different names. The second adjustment is the sector lash adjustment. Always use the manufacturers recommended procedures and specifications. This adjustment removes any worm shaft axial end play while providing the least amount of resistance to shaft movement. This adjustment is measured using an inch pound torque wrench.
The sector shaft lash adjustment is made after the worm shaft bearing preload. This adjustment must be set by turning the adjustment screw in and out of the gear boxes top plate. It can usually be seen be looking down over the fender at the top of the steering gear. The manufacturers procedure will likely have you center the stub shaft before adjusting the sector shaft. Loosen the lock nut and turn the adjustment screw in to decrease the lash and remove any looseness in the wheel and out to increase the steering effort required to turn the wheel. This is a sensitive measurement usually somewhere around 5-6 inch pounds at the ends and may increase to 10-12 inch pounds in the center. Always check with the vehicle manufacturers specifications.
