Cougar/XR7 V8-4.6L VIN W (1997)
Steering Gear: Description and Operation
NOTE: The power rack and pinion steering gear is serviced as a power steering short rack. The front wheel spindle tie rods and tie rod ends are
serviced separately.
DESCRIPTION
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The power rack and pinion steering gear incorporates quick connect fittings for the power steering pressure hose and power steering return
hose that allow the lines to swivel this is normal and does not indicate loose fittings.
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The Ford integral power rack and pinion steering gear has a 15:1 constant ratio.
MECHANICAL OPERATION
The power rack and pinion steering gear uses an integral piston and rack design to provide power-assisted vehicle steering control.
HYDRAULIC OPERATION
The power rack and pinion steering gear uses integral valving to direct pump flow and control pressure as required in order to reduce steering
effort during operation. The rotary design control valve uses relative rotational motion of the power steering gear input shaft and control to the
valve sleeve to direct fluid flow. When the steering wheel is turned, resistance of the wheels and the weight of the vehicle cause a torsion bar in the
gear to twist.
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This twist changes the position of the valve spool and sleeve ports, directing fluid under pressure to the appropriate end of the power cylinder.
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The difference in pressure forces on the piston helps move the steering gear rack to assist turning effort.
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The piston is attached directly to the steering gear rack and the steering gear housing functions as the power cylinder.
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The fluid in the opposite end of the power cylinder is forced to the control valve and back to the power steering pump reservoir.
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When the driver stops applying steering effort, the valve is forced back to a centered position by the torsion bar.
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When this occurs, pressure is equalized on both sides of the piston and the front wheels tend to return to a straight-ahead position.
