(4) Read pressures on both gauges as throttle lever
on transaxle is moved from full clockwise position to
full counterclockwise position.
(5) Line pressure should read 52 to 58 psi with
throttle lever clockwise. Pressure should gradually
increase to 80 to 88 psi. as lever is moved counter-
clockwise.
(6) Lubrication pressure should be 10 to 25 psi
with lever clockwise and 10 to 35 psi with lever at
full counterclockwise.
(7) This tests pump output, pressure regulation,
and condition of rear clutch and lubrication hydraulic
circuits.
TEST THREE (SELECTOR IN D)
(1) Attach gauges to line and kickdown release
ports.
(2) Operate engine at 1600 rpm for test.
(3) Move selector lever on transaxle two detents
forward from full rearward position. This is selector
D position.
(4) Read pressures on both gauges as throttle lever
on transaxle is moved from full clockwise to the full
counterclockwise position.
(5) Line pressure should read 52 to 58 psi with
throttle lever clockwise. Pressure should gradually
increase to 80 to 88 psi. as lever is moved counter-
clockwise.
(6) Kickdown release is pressurized only in direct
drive and should be same as line pressure within 3
psi, up to kickdown point.
(7) This tests pump output, pressure regulation,
and condition of rear clutch, front clutch, and
hydraulic circuits.
TEST FOUR (SELECTOR IN REVERSE)
(1) Attach 300 psi gauge (C-3292SP) to low-reverse
port.
(2) Operate engine at 1600 rpm for test.
(3) Move selector lever on transaxle four detents
forward from full rearward position. This is selector
R position.
(4) Low/reverse pressure should read 180 to 220
psi with throttle lever clockwise. Pressure should
gradually increase to 260 to 300 psi. as lever is
moved counterclockwise.(5) This tests pump output, pressure regulation,
and condition of front clutch and rear servo hydraulic
circuits.
(6) Move selector lever on transaxle to D position
to check that low/reverse pressure drops to zero.
(7) This tests for leakage into rear servo, due to
case porosity, which can cause reverse band burn out.
TEST RESULT INDICATIONS
(1) If proper line pressure, minimum to maximum,
is found in any one test, the pump and pressure reg-
ulator are working properly.
(2) Low pressure in D, 1, and 2 but correct pres-
sure in R, indicates rear clutch circuit leakage.
(3) Low pressure in D and R, but correct pressure
in 1 indicates front clutch circuit leakage.
(4) Low pressure in R and 1, but correct pressure
in 2 indicates rear servo circuit leakage.
(5) Low line pressure in all positions indicates a
defective pump, a clogged filter, or a stuck pressure
regulator valve.
GOVERNOR PRESSURE
Test only if transaxle shifts at wrong vehicle
speeds when throttle cable is correctly adjusted.
(1) Connect a 100 psi gauge to governor pressure
port. It is located at lower right side of case, below
differential cover (Fig. 2).
(2) Operate transaxle in third gear to read pres-
sures. The governor pressure should respond
smoothly to changes in mph and should return to 0
to 3 psi when vehicle is stopped. High pressure
(above 3 psi) at standstill will prevent the transaxle
from downshifting.
THROTTLE PRESSURE
No gauge port is provided for throttle pressure.
Incorrect throttle pressure should be suspected if
part throttle upshift speeds are either delayed or
occur too early in relation to vehicle speed. Engine
runaway on shifts can also be an indicator of low
throttle pressure setting, or misadjusted throttle
cable.
In no case should throttle pressure be adjusted
until the transaxle throttle cable adjustment has
been verified to be correct.
21 - 34 31TH AUTOMATIC TRANSAXLERS
31TH AUTOMATIC TRANSAXLE (Continued)
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(8) Install and torque oil pan-to-transaxle bolts
(Fig. 339) to 19 N´m (165 in. lbs.).
(9) Lower vehicle.
(10) Connect torque converter clutch solenoid.
(11) Connect gearshift cable to manual valve lever.
(12) Connect throttle valve cable to throttle valve
lever at transaxle.
(13) Connect battery negative cable.
ADJUSTMENTS
HYDRAULIC CONTROL PRESSURE
ADJUSTMENTS
LINE PRESSURE
An incorrect throttle pressure setting will cause incor-
rect line pressure readings even though line pressure
adjustment is correct. Always inspect and correct throttle
pressure adjustment before adjusting the line pressure.
The approximate adjustment for line pressure is 1-5/16
inches, measured from valve body to inner edge of adjust-
ing nut. However, due to manufacturing tolerances, the
adjustment can be varied to obtain specified line pres-
sure.
The adjusting screw may be turned with an Allen
wrench. One complete turn of adjusting screw
changes closed throttle line pressure approximately
1-2/3 psi. Turning adjusting screw counterclockwise
increases pressure, and clockwise decreases pressure.
THROTTLE PRESSURE
Throttle pressures cannot be tested accurately;
therefore, the adjustment should be measured if a
malfunction is evident.
(1) Insert gauge pin of Tool C-3763 between the
throttle lever cam and kickdown valve.(2) By pushing in on tool, compress kickdown
valve against its spring so throttle valve is com-
pletely bottomed inside the valve body.
(3) While compressing spring, turn throttle lever
stop screw with adapter C-4553. Turn until head of
screw touches throttle lever tang, with throttle lever
cam touching tool and throttle valve bottomed. Be
sure adjustment is made with spring fully com-
pressed and valve bottomed in the valve body.
VEHICLE SPEED SENSOR/
PINION GEAR
REMOVAL
(1)Remove harness connector from sensor (Fig. 340).
Be sure weather seal stays on harness connector.
(2) Remove bolt securing the sensor in the exten-
sion housing (Fig. 340) .
(3) Carefully pull sensor and pinion gear assembly
out of extension housing.
(4) Remove pinion gear from sensor (Fig. 340) .
(5) Inspect pinion gear for damage (missing teeth,
etc.) and replace as necessary.
NOTE: When removing vehicle speed sensor for
any reason, a new o-ring MUST be used.
INSTALLATION
(1) Install vehicle speed sensor and pinion gear to
extension housing with new o-ring (Fig. 340).
(2) Install bolt and torque to 7 N´m (60 in. lbs.).
(3) Connect connector.
(4) Lower vehicle.
Fig. 339 Transaxle Oil Pan Bolts
1 - TRANSAXLE OIL PAN
2 - OIL PAN BOLTS
Fig. 340 Vehicle Speed Sensor Removal/Installation
1 - CONNECTOR
2 - SPEEDO PINION
3 - O-RING
4 - SENSOR
21 - 160 31TH AUTOMATIC TRANSAXLERS
VALVE BODY (Continued)
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