
(25) Turn the key to OFF and remove the scan tool
from the vehicle.
(26) Test the operation of the horn, wipers and any
other functions that are steering column operated. If
applicable, reset the radio and the clock.
(27) If the steering column is a tilt column, verify
the tilt mechanism operates properly.
(28) Road test the vehicle to ensure proper opera-
tion of the steering system and the speed control sys-
tem.
STEERING COLUMN LOWER COUPLING
NOTE: Before proceeding with this removal and
installation procedure, review SERVICE WARNINGS
AND CAUTIONS at the beginning of REMOVAL AND
INSTALLATION in this section and in STEERING
GEAR.
REMOVAL
(1) Place the steering wheel in the STRAIGHT-
AHEAD position. Using a steering wheel holder, lock
the steering wheel in place to keep it from rotating
(Fig. 21). This keeps the clockspring in the proper
orientation.
(2) Inside the passenger compartment, remove the
steering column coupling retainer pin, back off the
pinch bolt nut, and remove the steering column cou-
pling pinch bolt (Fig. 22) (the pinch bolt nut is caged
to the coupling and is not removable). Separate the
upper and lower steering column couplings.
(3) Raise the vehicle. Refer to HOISTING in the
LUBRICATION AND MAINTENANCE group in this
service manual for the correct lifting procedure.(4) Release the locking tab on the wiring harness
connector for the power steering fluid pressure
switch before connector removal. Remove the wiring
harness connector from the power steering fluid pres-
sure switch (Fig. 23).
(5) Remove the bolt mounting the engine torque
strut to the right forward corner of the front suspen-
sion crossmember (Fig. 24).
Fig. 21 Steering Wheel Holder
1 ± STEERING WHEEL
2 ± STEERING WHEEL HOLDER
3 ± DRIVERS SEAT
Fig. 22 Steering Column Couplings
1 ± STEERING COLUMN UPPER COUPLING
2 ± PINCH BOLT
3 ± STEERING COLUMN LOWER COUPLING
4 ± BRAKE PEDAL
5 ± NUT
6 ± RETAINER PIN
Fig. 23 Power Steering Fluid Pressure Switch
1 ± WIRING HARNESS CONNECTOR
2 ± POWER STEERING GEAR
3 ± POWER STEERING FLUID PRESSURE SWITCH
4 ± REAR OF FRONT SUSPENSION CROSSMEMBER
19 - 38 STEERINGPL
REMOVAL AND INSTALLATION (Continued)

against the body and frame rails of the vehicle. As
the crossmember is raised, carefully guide the steer-
ing column lower coupling up through its hole in the
dash panel.
(4) Start the two rear crossmember mounting bolts
into the tapping plates mounted in the body. The
right side bolt can be viewed in the mounting bolt
figure (Fig. 24). The left side bolt is located in the
same location on the other side of the vehicle. Next,
install the two front mounting bolts attaching front
suspension crossmember to frame rails of vehicle.
Lightly tighten all four mounting bolts to a approxi-mately 2 N´m (20 in. lbs.) to hold the front suspen-
sion crossmember in position.
NOTE: When reinstalling the front suspension
crossmember back in the vehicle, it is very impor-
tant that the crossmember be attached to the body
in exactly the same spot as when it was removed.
Otherwise, the vehicle's wheel alignment settings
(caster and camber) will be lost.
(5) Using a soft face hammer, tap the front suspen-
sion crossmember back-and-forth or side-to-side until
it is aligned with the previously scribed positioning
marks on the body of the vehicle (Fig. 25). Once the
front suspension crossmember is correctly positioned,
tighten the rear two crossmember mounting bolts to
a torque of 203 N´m (150 ft. lbs.), then tighten the
front two crossmember mounting bolts to a torque of
142 N´m (105 ft. lbs.).
(6) Fasten the engine torque strut to the right for-
ward corner of the front suspension crossmember
using its mounting bolt (Fig. 24). Follow the proce-
dure described in the ENGINE service manual group
to properly align and tighten the torque strut mount-
ing bolts.
(7) Reconnect the wiring harness connector to the
power steering fluid pressure switch (Fig. 23). Be
sure the locking tab on the wiring harness connector
is securely latched.
(8) Lower the vehicle to ground level.
(9) Install the dash-to-lower coupling seal in place
over the lower coupling's plastic collar.
NOTE: Verify that grease is present on the lip of
the dash-to-coupling seal where it contacts the cou-
pling's plastic collar.
(10) Inside the passenger compartment, reconnect
the steering column lower coupling to the steering
column upper coupling (Fig. 22). Install the coupling
pinch bolt an tighten the pinch bolt nut to a torque of
28 N´m (250 in. lbs.). Install the pinch bolt retainer
pin.
(11) Remove the steering wheel holder.
(12) While looking under the instrument panel at
the lower coupling, rotate the steering wheel back-
and-forth to verify that the lower coupling does not
squeak against the dash-to-coupling seal.
Fig. 26 Crossmember Lowered
1 ± STEERING COLUMN LOWER COUPLING
2 ± POWER STEERING GEAR
3 ± FRONT SUSPENSION CROSSMEMBER
4 ± TRANSMISSION JACK
Fig. 27 Coupling Roll Pin
1 ± STEERING COLUMN LOWER COUPLING
2 ± POWER STEERING GEAR PINION SHAFT
3 ± ROLL PIN
4 ± ROLL PIN PUNCH
19 - 40 STEERINGPL
REMOVAL AND INSTALLATION (Continued)

LOW LUBRICANT LEVEL
Insufficient transaxle lubricant is usually the
result of leaks, or inaccurate fluid level check or refill
method. Leakage is evident by the presence of oil
around the leak point. If leakage is not evident, the
condition is probably the result of an underfill.
If air±powered lubrication equipment is used to fill
a transaxle, be sure the equipment is properly cali-
brated. Equipment out of calibration can lead to an
underfill condition.
FLUID LEAKS
Fluid leaks can occur around the input shaft seal,
axleshaft seals, case split lines, and the end cover. Be
careful not to misdiagnose an input shaft seal leak
for an engine rear main seal leak. Also, the transaxle
case sealer (split line) will accumulate dirt and look
like an oil leak.
CLUTCH PROBLEMS
Worn, damaged, or misaligned clutch components
can cause difficult shifting, gear clash, and noise.
A worn or damaged clutch disc, pressure plate, or
release bearing can cause hard shifting and gear
clash.
SERVICE PROCEDURES
FLUID DRAIN AND FILL
All NV T350 (A-578) transaxles are equipped with
a fill plug. The fill plug is located on the left side of
the transaxle differential area (Fig. 3). The fluid level
should be within 3/16 inch from the bottom of the
transaxle fill hole (vehicle must be level when check-
ing).All NV T350 (A-578) transaxles are equipped with
a drain plug. The drain plug is located on the lower
right side of the transaxle differential housing (Fig.
4). Tighten drain plug to 28 N´m (250 in. lbs.)
Dry fill lubricant capacity is approximately 1.9-2.2
liters (4.0-4.6 pints). Wipe the outside of the tran-
saxle if any lubricant spills.
REMOVAL AND INSTALLATION
GEARSHIFT KNOB
REMOVAL
(1)Pull shifter boot down and away from shifter knob.
(2) Push down on knob and rotate clockwise to
remove (Fig. 5).
Fig. 3 Fill Plug Location
1 ± RUBBER FILL PLUG
2 ± LEFT DRIVESHAFT SEAL
Fig. 4 Drain Plug Location
1 ± RIGHT DRIVESHAFT SEAL
2 ± DRAIN PLUG
Fig. 5 Gearshift Knob Removal
1 ± GEARSHIFT KNOB
21 - 4 TRANSAXLEPL
DIAGNOSIS AND TESTING (Continued)

DISASSEMBLY AND ASSEMBLY
TRANSAXLE
The NV T350 (A-578) transaxle internal compo-
nents can be serviced only by separating the gear
case from the bellhousing case.
CAUTION: The transaxle output shaft is serviced as
a unit. No disassembly and reassembly is possible.
Damage to the transaxle may result.
DISASSEMBLY
(1) Place transaxle on bench.
(2) Remove the clutch release bearing and fork.
Move the release fork and bearing to an in-line posi-
tion. Grasp the release lever with two hands in the
pivot stud socket area. Pull with even pressure to
release the fork from the pivot stud.
CAUTION: Do not use a screwdriver or pry bar to
release the fork as this may cause damage to the
fork and/or clip.
(3) Remove shift levers by driving out the roll pins.
(4) Remove transaxle case half bolts (Fig. 46).
(5) Place two screwdrivers into the slots provided
in the case halves near the dowels (Fig. 47). Separate
the case halves (Fig. 48).
Fig. 46 Case Bolts
1 ± CASE BOLTS
Fig. 47 Transaxle Case Halves
1 ± BELLHOUSING HALF
2 ± GEAR CASE HALF
Fig. 48 Separate Case Halves
1±PRYTOOL
2 ± CASE HALVES
3 ± PRY SLOT
21 - 18 TRANSAXLEPL

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)

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

FLUID LEVEL AND CONDITION
NOTE: The transmission and differential sump have
a common oil sump with a communicating opening
between the two.
The torque converter fills in both the P (Park) and
N (Neutral) positions. Place the selector lever in P
(Park) to be sure that the fluid level check is accu-
rate.The engine should be running at idle
speed for at least one minute, with the vehicle
on level ground. This will ensure complete oil
level stabilization between differential and
transmission.The fluid should be at normal operat-
ing temperature (approximately 82É C. or 180É F.).
The fluid level is correct if it is in the HOT region
(cross-hatched area) on the dipstick (Fig. 1).
Low fluid level can cause a variety of conditions,
because it allows the pump to take in air along with
the fluid. As in any hydraulic system, air bubbles
make the fluid spongy therefore, pressures will be
low and will build up slowly.
Improper filling also can raise the fluid level too
high. When the transaxle has too much fluid, the
gears churn up foam and cause the same conditions
that occur with a low fluid level.
In either case, the air bubbles can cause overheat-
ing, fluid oxidation, and varnishing. This can inter-
fere with normal valve, clutch, and servo operation.
Foaming also can result in fluid escaping from the
transaxle dipstick, where it may be mistaken for a
leak.
Along with fluid level, it is important to check the
condition of the fluid. When the fluid smells burned,
or is contaminated with metal or friction material
particles, a complete transaxle overhaul is needed.
Be sure to examine the fluid on the dipstick closely.
If there is any doubt about its condition, remove the
oil pan and inspect.
TORQUE CONVERTER CLUTCH
A torque converter clutch is standard on all vehi-
cles. The torque converter clutch is activated only in
direct drive and is controlled by the engine electron-
ics. A solenoid on the valve body, is powered by the
powertrain control module to activate the torque con-
verter clutch.
HYDRAULIC CONTROL SYSTEM
The hydraulic control system makes the transaxle
fully automatic, and has four important functions to
perform. The components of any automatic control
system may be grouped into the following basic
groups:
²Pressure supply system
²Pressure regulating valves
²Flow control valves
²Clutches
²Band servos
Taking each of these basic groups or systems in
turn, the control system may be described as follows:
PRESSURE SUPPLY SYSTEM
The pressure supply system consists of an oil pump
driven by the engine through the torque converter.
The single pump furnishes pressure for all hydraulic
and lubrication requirements.Oil pump housing
assemblies are available with preselected pump
gears.
PRESSURE REGULATING VALVES
The pressure regulating valve controls line pres-
sure dependent on throttle opening. The governor
valve transmits regulated pressure to the valve body
(in conjunction with vehicle speed) to control upshift
and downshift.
The throttle valve transmits regulated pressure to
the transaxle (dependent on throttle position) to con-
trol upshift and downshift.
FLOW CONTROL VALVES
The manual valve provides the different transaxle
drive ranges selected by the vehicle operator.
The 1-2 shift valve automatically shifts the tran-
saxle from first to second or from second to first,
depending on the vehicle operation.
The 2-3 shift valve automatically shifts the tran-
saxle from second to third or from third to second
depending on the vehicle operation.
Fig. 1 Transaxle Dipstick
1 ± TRANSAXLE DIPSTICK
21 - 56 TRANSAXLEPL
DESCRIPTION AND OPERATION (Continued)

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)