Subaru XT 1988 Service Manual page 546

3-2 AUTOMATIC TRANSMISSION AND DIFFERENTIAL
(7) Shift Valve A and 4-2 Relay Valve
Shift valve A
The pressure from the solenoid 1 pushes the valve to the left,
wh ile spring force pushes the valve to the right .
• In 2nd or 3rd speed: Shift solenoid 1 pressure is OFF.
The valve is in condition (a). Oil pressure from passage
®
is applied to the servo 2A chamber from oil passage
® .
• In 4th to 2nd shift down:
Oil from oil passage
®
is applied to the servo 4A chamber
and 4·2 relay valve through passage
(j)
if 3R 4A pressure
exists.
From shift
(a)~~
_ _
(b)
"0" range
pressu re
4·2 sequence
"0" range
From shift 2A pressure
Shift
valve
6
4A
• In 1st or 4th speed: Shift solenoid 1 pressure is ON.
The valve is in condition (D). In F2 range 1st speed, or
hold range 1st speed, oil from passage
CD
is applied to the
L&R/B from oil passage
@.
In 4th speed position, oil
pressure from passage
®
is applied to the servo 4A
chamber through oil passage
(j).
4-2 sequence
Sh ift soleniod
1 pressure
To shift
pressure
"0" range pressure
X
(a)
(b)
Fs
(Spring force)
FSOLl
(Force of
Fs
(Spring force)
sh ift solenoid
pressure 1)
4A
2A
Fig. 49
4-2 relay valves
The force generated by 4A pressure pushes the valve to the
left, while the spring force pushes the valve to the right. When
shifting from 4th to 2nd, status (a) is attained if 4A pressure
exists. Oil from passage
@
is routed to the 4·2 sequence valve
via shift valve B from oil passage
®.
32
To valve A
L3·631