Mustang Cobra V8-281 4.6L DOHC VIN V MFI (1997)
Steering Gear: Description and Operation
DESCRIPTION
The power rack and pinion steering gear uses integral valving that directs power steering pump flow and controls pressure as required to reduce
steering effort during operation. The power rack and pinion steering gear is serviced as a power steering short rack.
OPERATION
The power rack and pinion steering gear uses an integral valve and rack and piston design to provide power-assisted vehicle steering control. The
power rack and pinion steering gear operates by integral valving which directs pump flow and controls pressure as required to reduce steering
effort during operation.The rotary design control valve uses relative rotational motion of the power steering gear input shaft to the valve sleeve to
direct fluid flow. When the steering wheel is turned:
1. Resistance of the wheels and the weight of the vehicle cause a torsion bar to twist.
2. This twisting changes the position of the valve spool and sleeve ports, directing fluid under pressure to the appropriate end of the power
cylinder.
3. The difference in pressure forces on the piston helps move the steering gear rack to assist turning effort.
4. The piston is attached directly to the rack and the steering gear housing functions as the power cylinder.
5. The oil in the opposite end of the power cylinder is forced to the control valve and back to the power steering oil reservoir.
6. When the driver stops applying steering effort, the valve is forced back to a centered position by the torsion bar. When this occurs, pressure is
equalized on both sides of the piston and the front wheels tend to return to a straight-ahead position.
Located in the power steering pump valve body, the pressure relief valve limits hydraulic pressure within the power rack and pinion steering gear
to a preset maximum.
