G 20 Van V6-262 4.3L VIN Z (1993)
Steering Gear: Description and Operation
Saginaw Integral Power Steering Gear
Fig. 1 Exploded view of power steering gear
The power steering gear has a recirculating ball system which acts as a rolling thread between the worm shaft and the rack piston, Fig. 1. The worm
shaft is supported by a thrust bearing preload and two conical thrust races at the lower end, and a bearing assembly in the adjuster plug at the upper end.
The control valve in the steering gear directs the power steering fluid to either side of the rack piston. The rack piston converts the hydraulic pressure
into a mechanical force. If the steering system loses hydraulic pressure, the vehicle can be controlled manually.
When the worm shaft is turned right, the rack piston moves up in the gear while turning left moves the rack piston down in the gear. The rack piston
teeth mesh with the pitman shaft sector. Turning the worm shaft turns the pitman shaft, which turns the wheels through the steering linkage.
