Subaru SVX 1992 Manual page 393

3- 2 (M1ool AUTOMATIC TRANSMISSION AND DIFFERENTIAL
M MECHANISM AND FUNCTION
1 . General
This system utilizes a microcomputer for accurate con-
trol of the vehicle speed, engine brake operation,
lock-up operation, gear shift timing and others . It corre-
sponds to the throttle opening, actual vehicle speed,
engine rpm and range position signal . Further, this
system adopted an electronically controlled full-time
AWD system designed uniquely for SUBARU .
The AWD system has a transfer hydraulic pressure
control unit incorporating duty solenoid and a multi-
plate transfer (MPT) consisting of a wet type multi-plate
clutch on the rear of the automatic transmission section.
The control unit stores optimum transfer clutch torque
(duty ratio) data for various driving conditions . When
actual driving conditions (vehicle speed, throttle open-
ing, gear range, wheel slip, etc.) are detected by various
sensors, the control unit selects the most suitable duty
ratio from memory, and controls the transmitting torque
of the transfer clutch by means of the hydraulic pres-
sure controlling duty solenoid .
(Features)
1) Two one-way clutches and four accumulators are
used to reduce gear shift shock and gear select shock,
and a fully electronic control from 1st to 4th speeds,
hydraulic oil pressure (line pressure), lock-up operation,
etc .
2) A hydraulic lock-up type torque converter, variable
delivery oil pump, gear train with two sets of simple
planetary gears (permitting four forward and one re-
verse stage) are used to improve driving dynamics and
fuel consumption .
3) A push-pull cable featuring less vibration to the high
rigid transmission case and control unit is used for
improved quietness during driving.
4) The transfer clutch capacity can be accurately con-
trolled by means of the electronic control system . This
is especially effective for eliminating tight corner brak-
ing phenomenon which occurs at low speeds, thereby
achieving smooth driving .
5) An optimum rear wheel drive distribution is achieved
which corresponds to engine output and gear shift
position and improves fuel consumption and steering
stability .
6) For the car equipped with ABS, the braking perfor-
mance is improved by the control of the clutch and gear
locking at a particular shift position through ABS
operation-time control .
2