The power rack and pinion steering gear (3) has a rotary spool valve (4). The rotary spool valve (4) directs hydraulic fluid coming from the power steering pump to one side or the other side of the rack piston.

The integral rack piston is attached to the rack. The rack piston converts hydraulic pressure to a linear force. The linear force moves the rack to the left or to the right. This force is then transmitted through the inner and outer tie rods to the steering knuckles. This turns the wheels.

If hydraulic assist is not available, manual control is maintained. More steering effort is required under these conditions. The movement of the steering wheel is transferred through the valve to the pinion. The movement of the pinion is then transferred through the pinion teeth. This condition forces the teeth on the rack to mesh. This causes the rack to move.

The Magnasteer™ Power Steering varies the steering effort in order to provide the driver with the following conditions:

As vehicle speed increases, the steering effort is also increased. At highway speeds, the amount of steering effort approaches a manual steering feel for maximum control and enhanced vehicle stability. Magnasteer™ Power Steering provides a sense of total vehicle control at all driving ranges.