Subaru XT 1988 Service Manual page 701

TRANSMISSON CONTROL SYSTEM
3-3
In 4-Wheel Drive
Diaphragm
Intake manifold vacuum
®
4WD pilot lamp switch
7
Transfer fork
@Transfer rod
Lever (transfer shifted
Check valve
(Atmospheric
pressure)
CD
4WD switch (PUSH)
4WD pilot lamp
CE'
Intake manifold
Fig.
2
When the 4WD switch button
CD
is pushed in with the engine
on, the 4WD solenoid valve
@
is energized and the valve
@
opens. At this time, the vacuum pressure from the intake
manifold
@
enters the valve so that the diaphragm inside
the vacuum chamber is pulled in the direction of the arrow.
The transfer rod
@
connected to the diaphragm also moves
3
--0--+-_---
Power source
L3-236
in that direction. This causes the FWD-4WD selector clutch
®
to engage the spline of the transfer gear so that the vehicle is
set in 4-wheel drive. In 4-wheel drive, the 4WD pilot lamp
switch
®
turns on the 4WD pilot lamp
®
in the combination
meter. Changing from 4-wheel drive to front-wheel drive is
accomplished by pushing the 4WD switch button
CD·