Description & Operation

Steering gear is a recirculating ball type and consists of a ball nut connected to steering worm and in mesh with sector gear. Gears are basically the same for all models and service procedures will apply to all gears unless noted otherwise. Precision finished helical grooves within ball nut match helical grooves in worm. Ball bearings roll within grooves when steering wheel is turned. There are two complete circuits using tubular ball guides to deflect balls away from their helical path at one end of groove and guide them back to other end. When steering wheel is turned to right, nut moves upward; when turned to left, nut moves downward. The teeth on sector (forged as part of pitman shaft) and the ball nut are so designed that a tighter fit exists between the two when the front wheels are straight ahead. Proper engagement between sector and ball nut is obtained by an adjusting screw, which moves pitman shaft endwise, permitting desired engagement of tapered teeth of the ball nut and sector gear. Worm bearing adjuster can be turned to provide proper preloading of the upper and lower bearings.