Subaru XT 1988 Service Manual page 544

3-2
AUTOMATIC TRANSMISSION AND DIFFERENTIAL
PL duty pressure
(
Accumulator piston )
Upper: after shifting gear
Lower: before shifting gear
"0" range pressure X
FR SOL
(Force of PL duty pressure)
ACCUM
Line pressure
solenoid
Pilot pressure
Control unit
Spring force
(Force of accumulator control pressure)
To accumulator
Fig. 46
(5) Shuttle Shift Valve 0
The 2A pressure pushes the valve to the right, while the spring
force pushes the valve to the left .
• In 1st speed, and in "N", "R", or "P" range:
The shuttle shift valve is in condition (b). The pilot pressure
flows to the lock-up control valve and keeps the torque
converter lock-up clutch in the unlocked position (i.e., the
condition of torque converter coupling).
• In 2nd, 3rd, or 4th speed:
The shuttle shift valve D is in condition (a). The lock-up
duty pressure is routed to the lock-up control valve, and
keeps the torque converter in the lock-up (direct-connec-
tion) position.
(Force of 2A
pressure)
Fig. 47
30
L3-628
To lock-up control valve
control valve
Lock-up duty pressure
To forward To lock-up
control valve control valve
Fs
(Spring force)
L3-925
t