9000 L4-2290cc 2.3L DOHC Turbo EFI (1992)
Power Steering Valve: Description and Operation
The control valve consists of a valve (1), a spool (2), a torsion rod (3) and a pinion (4). The intermediate shaft of the steering column assembly is
connected to the valve by means of a universal joint. One end of the torsion rod is secured to the upper end of the valve by means of a pin (5).
The other end of the torsion rod is press-fitted in the pinion, to which the spool is secured by means of a pin (6), with the result that the spool follows the
rotation of the pin exactly. A splined joint between the valve and the pinion constitutes an additional safety feature. The top of the pinion is supported in
a needle bearing. The bottom is supported by a ball bearing. There is a plastic bush between the valve spool and the pinion.
A spring loaded damper yoke presses the rack against the pinion. The damper yoke is adjustable to compensate for any backlash due to wear. The valve
housing, that is part of the rack housing, incorporates four hydraulic connections for the hydraulic fluid flow; two for the pump and return, and two for
servo cylinder flow and return. The spool has three radial grooves (7). Hydraulic fluid is pumped to the middle one. When the car is in the straight ahead
position, the control valve is open and the fluid flows up through the valve and back to the pump via the chamber at the top of the spool.
