Power Rack and Pinion

Except for differences in valve machining, the design of the SSPS power rack and pinion assembly is the same as for the a non-SSPS system. The steering wheel movement is transferred to the pinion via the intermediate shaft. The pinion moves the rack left or right through meshing the pinion and the rack teeth. The force is then transmitted through the tie rods and steering knuckle to steer the wheels.

The power rack and pinion steering system has a rotary control valve which directs the hydraulic fluid from the power steering pump to one side or the other side of the rack piston. The piston is attached to the rack and uses hydraulic pressure to move the rack left or right. The rotary control valve regulates the degree of assist by responding to the driver's torque input.

If hydraulic assist is not available, manual control is maintained. However, under this condition, more steering effort is required.