Subaru XT 1988 Service Manual page 550

3-2 AUTOMATIC TRANSMISSION AND DIFFERENTIAL
(14) 1st Reducing Valve
This valve is pushed to the left by the oil in chamber
®
coming from passage
CD.
If the oil pressure exceeds spring
pressure, the valve moves to the left, and the oil is drained.
Hence, the 1 st reducing pressure remains constant.
Fs
(Spri ng force}
Fig. 56
1 st reducing pressure
(To L & R brake via shift valve A.B}
"2"
range pressure
"2"
range pressure
F1st RED
(Force of 1st
reducing pressure}
1st reducing pressure
L3-638
(15) 3-2 Timing Valve
36
When shifting from "0" range 3rd to "0" range 2nd:
This valve switches the 3R pressure releasing time.
When oil passes through orifice A only:
The valve is set in condition (B), and the 3R release oil
passes through orifice A. Hence, release time is prolonged.
When oil passes through both orifice A and valve:
The valve is in condition (A), and the 3R release oil passes
through orifice A and the valve. Hence, release time is
shortened.
Overrunning clutch solenoid pressure
(Shift solenoid pressure}
+
3 R rei ease p ressu re
F
oVRte
SOL (Force of
overrunning clutch solenoid
pressure or shift solenoid
3 pressure}
Fig. 57
3R release pressure
To shift B valve
(16) Servo Charger Valve
Fs
(Spring force} ..
L3-929
When shifting from "0" range 3rd to "0" range 2nd:
In "D" range 3rd speed, the valve is in condition (A). Passage
CD
communicates with chamber
®.
If the 3R pressure
exceeds spring pressure, the valve shifts to condition (B),
where passage
®
communicates with chamber
®.
Accord-
ingly, the valve will remain in condition (B) as long as 2A
pressure exists. This means that oil can be fed to the servo 2A
chamber without passing through the orifice. Thus, it is
possible to quickly compensate for the oil drained through
the servo 3R chamber. This prevents engine racing while
downshifting.