Steering Gearbox - Honda Civic 1998 Service Manual

System Description
Steering Gearbox
The rack and-pinion type steering gearbox has a valve body unit incorporated with the pinion lo control the steering fluid
pressure. Steering fluid from the pump is regulated by a rotary valve in the valve body unit and is sent through the cylin
der line to the power cylinder, where hydraulic pressure is applied. The steering fluid in the other side of the power cylin-
der returns through the cylinder line and valve body unit to the reservoir.
VALVE BODY UNIT
CYLINDER LINE
To RESERVOIR +
From PUMP
ri
POWER CYLINDER
Valve Body Unit
Inside the valve body unit is the valve. which is coaxial with the pinion shaft, and controls the steering fluid pressure. The
valve housing is connected with the fluid line from the pump, the return line to the reservoir, and the two cylinder lines
from the respective power cylinder. The pinion shaft is double - structured with the input shatt connected to the pinion
gear, both of which are interconnected wlth the torsion bar.
The pin inserted in the valve and the pinion shaft groove engage; this allows the pinion shaft to rotate together with the
valve. Because of this construction, the difference in angle in the circumferential direction between the input sh8ft and the
valve becomes larger according to the torsional strength of the pinion or steering resistance. However. maximum torsion
betlveen the shafts is regulated by the engaged splines of the shafts at the pin engagement section to hold the torsion bar
within the set value.
This allows the steering system to function as an ordinary rack-and-pinion type steering if the steering fluid is not pressur-
ized because of a faulty pump.
VALVE
Diflerence in angle between the
input shaft and pinion shaft
PINION SHAFT
l a
INPUT SHAFT
-l
B
17-20
INPUT SHAFT