
(3) Stake pinion shaft retaining pin with a suitable
chisel (Fig. 132).
(4) Rotate the assembly two full revolutions both
clockwise and counterclockwise.
(4) Set up dial indicator as shown and record end
play (Fig. 133) (Fig. 134). Rotate side gear 90 degrees
and record another end play. Again, rotate side gear
90 degrees and record a final end play.
(5) Using the smallest end play recorded, shim
that side gear to within 0.001 to 0.013 inch. The
other side gear should be checked using the same
procedure.CAUTION: Side gear end play must be within 0.001
to 0.013 inch. Five select thrust washers are avail-
able: 0.027, 0.032, 0.037, 0.042, and 0.047 inch.
(6) After the end play is measured and adjusted,
replace speedometer drive gear with a new one.
Install drive gear lip downward. For service informa-
tion, refer to Speedometer Drive Gear service in this
section.
SYNCHRONIZER
DISASSEMBLY
Place synchronizer in a clean shop towel and wrap.
Press on inner hub. Carefully open up shop towel
and remove springs, balls, keys, hub, and sleeve.
ASSEMBLY
(1) Position synchronizer hub onto a suitable hold-
ing fixture (input shaft). The synchronizer hubs are
directional. The hubs must be installed with theU
facing upward.
(2) Install springs into hub slot (Fig. 135).
(3) Insert key into hub and spring.
(4) Apply petroleum jelly to the hole in the key.
Insert balls into each key (Fig. 136).
(5) Slide sleeve over the hub and depress balls as
you carefully slip the sleeve into position (Fig. 137).
(6) Line up stop ring tang over the keys in the hub
(Fig. 138). Install stop rings. Center the keys and
balls by pushing on both stop rings.
Fig. 132 Staking Retaining Pin
1 ± PINION SHAFT RETAINING PIN
2 ± SPEEDOMETER DRIVE GEAR
Fig. 133 Checking Side Gear End Play (Typical)
1 ± SPECIAL TOOL C-4996 (NOTE POSITION)
2 ± DIAL INDICATOR SET
3 ± DIFFERENTIAL ASSEMBLY
4 ± SIDE GEAR
Fig. 134 Checking Side Gear End Play (Typical)
1 ± SPECIAL TOOL C-4996 (NOTE POSITION)
2 ± DIAL INDICATOR SET
3 ± DIFFERENTIAL ASSEMBLY
PLTRANSAXLE 21 - 41
DISASSEMBLY AND ASSEMBLY (Continued)

SHIFT CROSSOVER SHAFT BUSHING
REMOVAL
(1) Install slide hammer #3752 through the cross-
over bushing.
(2) Thread nut and washer onto slide hammer.
(3) Using the slide hammer, remove the crossover
shaft bushing (Fig. 155).
INSTALLATION
(1) Position the replacement crossover shaft bush-
ing over the crossover shaft bushing bore.
(2) Using an appropriate size deep±well socket,
install the crossover shaft bushing into the bushing
bore.
REAR BEARING OIL FEED TROUGH
The bearing oil feed trough is retained in the case
by a pin that is molded into the case and clips that
are part of the trough (Fig. 156).
REMOVAL
(1) Using light plier pressure, squeeze the clips
together at the rear of the trough.
(2) Slide the trough over the retaining pin that
locates the trough in the case.
INSTALLATION
(1) Reverse removal procedure to install oil feed
trough.
CLEANING AND INSPECTION
TRANSAXLE
Clean the gears, bearings, shafts, synchronizers,
thrust washers, oil feeder, shift mechanism, gear
case, and bellhousing with solvent. Dry all parts
except the bearings with compressed air. Allow the
bearings to either air dry or wipe them dry with
clean shop towels.
Inspect the gears, bearings, shafts and thrust wash-
ers. Replace the bearings and cups if the rollers are
worn, chipped, cracked, flat spotted, or brinnelled, or if
the bearing cage is damaged or distorted. Replace the
thrust washers if cracked, chipped, or worn. Replace
the gears if the teeth are chipped, cracked, or worn
thin. Inspect the synchronizers. Replace the sleeve if
worn or damaged in any way. Replace the stop rings if
the friction material is burned, flaking off, or worn.
Check the condition of the synchro keys and springs.
Replace these parts if worn, cracked, or distorted.
SYNCHRONIZER
CLEAN
Do not attempt to clean the blocking rings in sol-
vent. The friction material will become contaminated.
Place synchronizer components in a suitable holder
and clean with solvent. Air dry.
INSPECT
Proper inspection of components involve:
²Teeth, for wear, scuffed, nicked, burred, or bro-
ken teeth
²Keys, for wear or distortion
²Balls and springs, for distortion, cracks, or wear
If any of these conditions exist in these compo-
nents, replace as necessary.
Fig. 155 Crossover Shaft Bushing Removal
1 ± SLIDE HAMMER
2 ± SHIFTER SHAFT BUSHING
Fig. 156 Oil Feed Trough
1 ± OIL FEED TROUGH
21 - 48 TRANSAXLEPL
DISASSEMBLY AND ASSEMBLY (Continued)

ADJUSTMENTS
GEARSHIFT CROSSOVER CABLE
(1) Pull shifter boot down and away from shifter
knob.
(2) Push down on knob and rotate clockwise to
remove (Fig. 157).
(3) Remove the center console assembly as shown
in (Fig. 158).
(4) Separate shifter boot from shifter assembly
(Fig. 159). Boot is retained to shifter by three push-
pin retainers.(5) Loosen crossover adjustment screw at shifter
assembly (Fig. 160).
(6) Pin transaxle crossover lever in 3-4 neutral
position using a 1/4 inch drill bit. Align hole in cross-
over lever with the hole in the boss on the transaxle
case (Fig. 161). Be sure drill bit goes into transaxle
case at least one±half inch.
(7) The shifter is spring±loaded and self±centering.
Allow shifter to rest in its neutral position. Torque
adjustment screw to 8 N´m (70 in. lbs.). Care must be
taken to avoid moving the shift mechanism off-center
during screw tightening.
(8) Remove drill bit from transaxle case and per-
form functional check by shifting transaxle into all
gears.
(9) Install boot to the shifter assembly (Fig. 159).
Fasten boot with the three retainers.
Fig. 157 Gearshift Knob Removal
1 ± GEARSHIFT KNOB
Fig. 158 Center Console Removal/InstallationÐ
Typical
1 ± CONSOLE
2 ± SCREW (4)
3 ± SCREW (2)
Fig. 159 Gearshift Boot Removal/Installation
1 ± BOOT
2 ± SHIFTER ASSEMBLY
Fig. 160 Crossover Adjustment Screw
1 ± CROSSOVER ADJUSTMENT SCREW
PLTRANSAXLE 21 - 49

(10) Install center console assembly (Fig. 158). Ver-
ify that boot is not pinched at console opening before
tightening.
(11) Install knob to shifter lever, align knob to
three o'clock position, push knob down to engage
spring and rotate counter clockwise (Fig. 162).
(12) Return shifter boot to its original position
(seated around knob lip).
BEARING ADJUSTMENT PROCEDURE
GENERAL RULES ON SERVICING BEARINGS
(1) Use extreme care when removing and install-
ing bearing cups and cones. Use only an arbor pressfor installation, as a hammer may not properly align
the bearing cup or cone. Burrs or nicks on the bear-
ing seat will give a false end play reading while
gauging for proper shims. Improperly seated bearing
cups and cones are subject to low±mileage failure.
(2) Bearing cups and cones should be replaced if
they show signs of pitting or heat distress. If distress
is seen on either the cup or bearing rollers, both cup
and cone must be replaced.
(3) Bearing preload and drag torque specifications
must be maintained to avoid premature bearing fail-
ures. Used (original) bearings may lose up to 50% of
their original drag torque after break in. All bearing
adjustments must be made with no other component
interference or gear intermesh.
(4) Replace bearings as a pair: If one differential
bearing is defective, replace both differential bear-
ings, if one input shaft bearing is defective, replace
both input shaft bearings.
(5) Bearing cones must not be reused if removed.
(6) Turning torque readings should be obtained
while smoothly rotating in either direction.
DIFFERENTIAL BEARING PRELOAD
ADJUSTMENT
NOTE: True bearing turning torque readings can be
obtained only with the geartrain removed from the
case.
(1) Remove bearing cup and existing shim from
clutch bellhousing case.
(2) Press in new bearing cup into bellhousing case
(or use a cup that has been ground down on the
outer edge for ease of measurement).
(3) Press in new bearing cup into gear case side.
(4) Oil differential bearings with Moparttype M.
S. 9417 Manual Transaxle Fluid. Install differential
assembly in transaxle gear case. Install clutch bell-
housing over gear case. Install and torque case bolts
to 29 N´m (21 ft. lbs.).
(5)
Position transaxle with bellhousing facing down
on workbench with C-clamps. Position dial indicator.
(6) Apply a medium load to differential with Tool
C-4995 and a T-handle, in the downward direction.
Roll differential assembly back and forth a number of
times. This will settle the bearings. Zero the dial
indicator. To obtain end play readings, apply a
medium load in an upward direction while rolling
differential assembly back and forth (Fig. 163).
Record end play.
(7) The shim required for proper bearing preload is
thetotal of end play, plus (constant) preload of
0.18mm (0.007 in.).Never combine shims to obtain
the required preload.
Fig. 161 Crossover Lever Pin Procedure
1±1¤488DRILL BIT
2 ± SELECTOR CABLE
3 ± CROSSOVER CABLE
Fig. 162 Gearshift Knob Installation
1 ± GEARSHIFT KNOB
2 ± SPRING
21 - 50 TRANSAXLEPL
ADJUSTMENTS (Continued)

(8) Remove case bolts. Remove clutch bellhousing
differential bearing cup. Install shim(s) selected in
Step 7. Then press the bearing cup into clutch bell-
housing.
(9) Install clutch bellhousing. Install and torque
case bolts to 26 N´m (19 ft. lbs.).
(10) Using Special Tool C-4995 and an inch-pound
torque wrench, check turning torque of the differen-
tial assembly (Fig. 164).The turning torque
should be 6 to 12 in. lbs. If the turning torque is
too high, install a 0.05mm (0.002 inch) thinner
shim. If the turning torque is too low, install a
0.05mm (0.002 inch) thicker shim.(11) Recheck turning torque. Repeat Step 10until
the proper turning torque is obtained.
SPECIFICATIONS
NV T350 (A-578) SPECIFICATIONS
DESCRIPTION TORQUE
Back-up Lamp Switch........ 24N´m(18ft.lbs.)
Crossover Cable Adj. Screw.... 8N´m(70in.lbs.)
Drain Plug............... 28N´m(250 in. lbs.)
Differential Ring Gear Bolts . . . 81 N´m (60 ft. lbs.)
Dust Shield to Transaxle.... 12N´m(105 in. lbs.)
End Plate Cover Bolts........ 29N´m(21ft.lbs.)
Lateral Bending Strut to Engine......... 81N´m
(60 ft. lbs.)
Lateral Bending Strut to Trans.......... 81N´m
(60 ft. lbs.)
Left Mount Through Bolt.... 108N´m(80ft.lbs.)
Left Mount to Transaxle...... 68N´m(50ft.lbs.)
Output Bearing Race Ret. Strap......... 11N´m
(96 in. lbs.)
Reverse Fork Bracket........ 11N´m(96in.lbs.)
Reverse Idler Shaft Bolt...... 26N´m(19ft.lbs.)
Shift Cable Bracket to Transaxle........ 28N´m
(250 in. lbs.)
Transaxle Case Bolts......... 29N´m(21ft.lbs.)
Transaxle to Engine Bolt...... 95N´m(70ft.lbs.)
Trans. to Eng. Intake Bkt. Bolts......... 95N´m
(70 ft. lbs.)
Vehicle Speed Sensor......... 7N´m(60in.lbs.)
Vertical Bending Strut to Engine........ 81N´m
(60 ft. lbs.)
Vertical Bending Strut to Trans.......... 81N´m
(60 ft. lbs.)
NOTE: Bolts that have thread sealer or torque lock
patches should not be reused. Always install new
bolts in these applications.
Fig. 163 Checking Differential Bearing End Play to
Determine Shim Thickness
1 ± T-HANDLE
2 ± DIAL INDICATOR SET
3 ± SPECIAL TOOL C-4995
Fig. 164 Checking Differential Bearing Turning
Torque
1 ± INCH-POUND TORQUE WRENCH
2 ± SPECIAL TOOL C-4995
NV T350 (A-578) MANUAL TRANSAXLE FLUID
FILL
TRANSAXLE METRIC
MEASUREU. S.
MEASURE
NV T350 1.9-2.2 Liters 2.0-2.3 Quarts
PLTRANSAXLE 21 - 51
ADJUSTMENTS (Continued)

SPECIAL TOOLS
NV T350 (A-578) MANUAL TRANSAXLE
Adapter Blocks C-293±45
Puller Press C-293±PA
Dial Indicator C-3339
Sleeve C-3717
Slide Hammer C-3752
Universal Handle C-4171
Bearing Installer C-4628
Seal Remover C-4680
Seal Installer C-4992
Torque Tool C-4995
21 - 52 TRANSAXLEPL

31TH AUTOMATIC TRANSAXLE
TABLE OF CONTENTS
page page
GENERAL INFORMATION
IN VEHICLE SERVICE.....................55
FLUID REQUIREMENTS...................55
DESCRIPTION AND OPERATION
31TH GENERAL INFORMATION..............55
FLUID LEVEL AND CONDITION..............56
TORQUE CONVERTER CLUTCH.............56
HYDRAULIC CONTROL SYSTEM.............56
PRESSURE SUPPLY SYSTEM...............56
PRESSURE REGULATING VALVES...........56
FLOW CONTROL VALVES..................56
CLUTCHES, BAND SERVOS, AND
ACCUMULATOR........................57
BRAKE TRANSMISSION SHIFT INTERLOCK
SYSTEM..............................57
GEARSHIFT AND PARKING LOCK CONTROLS . . 57
COOLER BYPASS VALVE..................57
TORQUE CONVERTER CLUTCH SOLENOID
WIRING CONNECTOR...................58
GOVERNOR.............................58
DIAGNOSIS AND TESTING
TRANSAXLE PRELIMINARY DIAGNOSIS.......58
ROAD TEST.............................65
HYDRAULIC PRESSURE TESTS.............66
CLUTCH AND SERVO AIR PRESSURE TESTS . . 68
FLUID LEAKAGE-TRANSAXLE TORQUE
CONVERTER HOUSING AREA.............70
BRAKE TRANSMISSION SHIFT INTERLOCK....70
SERVICE PROCEDURES
TRANSAXLE FLUID AND FILTER SERVICE.....70
ALUMINUM THREAD REPAIR...............71
FLUSHING COOLERS AND TUBES...........72
OIL PUMP VOLUME CHECK................72
REMOVAL AND INSTALLATION
GEARSHIFT CABLE.......................73
GEARSHIFT MECHANISM..................76
THROTTLE VALVE (KICKDOWN) CABLE.......77
BRAKE TRANSMISSION SHIFT INTERLOCK
CABLE...............................79
INTERLOCK MECHANISM..................82
VEHICLE SPEED SENSOR PINION GEAR......83
PARK/NEUTRAL STARTING AND BACK-UP
LAMP SWITCH.........................84TRANSAXLE AND TORQUE CONVERTER......84
PUMP OIL SEAL.........................88
DISASSEMBLY AND ASSEMBLY
TRANSAXLE............................89
VALVE BODY............................91
OIL PUMP.............................104
FRONT CLUTCH........................105
REAR CLUTCH ASSEMBLY................108
FRONT PLANETARY AND ANNULUS
GEAR-RECONDITION...................110
LOW/REVERSE (REAR) SERVO-
RECONDITION........................112
ACCUMULATOR-RECONDITION............113
KICKDOWN SERVO (CONTROLLED LOAD)-
RECONDITION........................113
TRANSFER SHAFT REPAIR................114
PARKING PAWL.........................121
OUTPUT SHAFT REPAIR..................121
DIFFERENTIAL REPAIR...................129
CLEANING AND INSPECTION
VALVE BODY...........................135
ADJUSTMENTS
GEARSHIFT CABLE......................135
THROTTLE VALVE CABLE ADJUSTMENT
PROCEDURE.........................136
BRAKE TRANSMISSION SHIFT INTERLOCK
SYSTEM.............................137
BAND ADJUSTMENT.....................138
HYDRAULIC CONTROL PRESSURE
ADJUSTMENTS.......................138
BEARING ADJUSTMENT PROCEDURES......138
OUTPUT SHAFT BEARING................139
DIFFERENTIAL BEARING.................139
TRANSFER SHAFT BEARING..............140
SCHEMATICS AND DIAGRAMS
31TH TRANSAXLE HYDRAULIC SCHEMATIC . . 142
SPECIFICATIONS
31TH AUTOMATIC TRANSAXLE.............150
31TH TRANSAXLE TORQUE SPECIFICATIONS . 150
SPECIAL TOOLS
31TH AUTOMATIC TRANSAXLE.............151
21 - 54 TRANSAXLEPL

The kickdown valve makes possible a forced down-
shift from third to second, second to first, or third to
first (depending on vehicle speed). This can be done
by depressing the accelerator pedal past the detent
feel near wide open throttle.
The shuttle valve has two separate functions and
performs each independently of the other. The first is
providing fast release of the kickdown band, and
smooth front clutch engagement when a lift-foot
upshift from second to third is made. The second
function is to regulate the application of the kick-
down servo and band when making third±to±second
kickdown.
The bypass valve provides for smooth application
of the kickdown band on 1-2 upshifts.
The torque converter clutch solenoid allows for the
electronic control of the torque converter clutch. It
also disengages the torque converter at closed throt-
tle. This is done during engine warm-up and part-
throttle acceleration.
The switch valve directs oil to apply the torque
converter clutch in one position. The switch valve
releases the torque converter clutch in the other posi-
tion.
CLUTCHES, BAND SERVOS, AND
ACCUMULATOR
The front and rear clutch pistons, and both servo
pistons, are moved hydraulically to engage the
clutches and apply the bands. The pistons are
released by spring tension when hydraulic pressure
is released. On the 2-3 upshift, the kickdown servo
piston is released by spring tension and hydraulic
pressure.
The accumulator controls the hydraulic pressure
on the apply±side of the kickdown servo during the
1-2 upshift; thereby cushioning the kickdown band
application at any throttle position.
BRAKE TRANSMISSION SHIFT INTERLOCK
SYSTEM
The Brake Transmission Shifter/Ignition Interlock
(BTSI) is a cable and solenoid operated system. It
interconnects the automatic transmission floor
mounted shifter to the steering column ignition
switch. The system locks the shifter into the PARK
position. The interlock system is engaged whenever
the ignition switch is in the LOCK or ACCESSORY
position. An additional electrically activated feature
will prevent shifting out of the PARK position unless
the brake pedal is depressed at least one-half inch. A
magnetic holding device integral to the interlock
cable is energized when the ignition is in the RUN
position. When the key is in the RUN position and
the brake pedal is depressed, the shifter is unlocked
and will move into any position. The interlock systemalso prevents the ignition switch from being turned
to the LOCK or ACCESSORY position, unless the
shifter is in the gated PARK position.
The following chart describes the normal operation
of the Brake Transmission Shift Interlock (BTSI) sys-
tem. If the ªexpected responseº differs from the vehi-
cle's response, then system repair and/or adjustment
is necessary.
GEARSHIFT AND PARKING LOCK CONTROLS
The transaxle is controlled by alever typegear-
shift incorporated within the console. The control has
six selector lever positions: P (Park), R (Reverse), N
(Neutral), and D (Drive), 2 (Second), and 1 (First).
The parking lock is applied by moving the selector
lever past a gate to the (P) position.Do not apply
the parking lock until the vehicle has stopped;
otherwise, a severe banging noise will occur.
COOLER BYPASS VALVE
Some 31TH transaxles are equipped with a cooler
bypass valve (Fig. 2). The valve is designed to bypass
the transaxle oil cooler circuit in cold weather condi-
tions, or when circuit restriction exceeds 25±30 p.s.i.
The valve consists of an integrated check ball and
spring, and a return tube to carry bypassed oil back
to the pump. The bypass valve is mounted to the
valve body transfer plate and is sealed with a rubber
o-ring seal (Fig. 3).
ACTION EXPECTED RESPONSE
1. Turn key to the ªOFFº
position.1. Shifter CAN be shifted
out of park.
2. Turn key to the
9ON/RUNº position.2. Shifter CANNOT be
shifted out of park.
3. Turn key to the
ªON/RUNº position and
depress the brake pedal.3. Shifter CAN be shifted
out of park.
4. Leave shifter in any
gear and try to return key
to the ªLOCKº or9ACCº
position.4. Key cannot be
returned to the ªLOCKº or
ªACCº position.
5. Return shifter to
ªPARKº and try to remove
the key.5. Key can be removed
(after returning to ªLOCKº
position).
6. With the key removed,
try to shift out of ªPARKº.6. Shifter cannot be
shifted out of ªPARKº.
NOTE: Any failure to meet these expected
responses requires system adjustment or repair.
PLTRANSAXLE 21 - 57
DESCRIPTION AND OPERATION (Continued)