(3) Carefully install the ignition switch. The
switch will snap over the retaining tabs (Fig. 16) .
Install mounting screw (Fig. 12).
(4) Install upper and lower shrouds.
(5) Install key cylinder (cylinder retaining tab will
depress only in the RUN position).
(6) Connect negative cable to battery.(7) Check for proper operation of ignition switch
and key-in warning switch.
LOCK CYLINDER HOUSING
DESCRIPTION - IGNITION INTERLOCK
All vehicles equipped with automatic transaxles
have an interlock system. The system prevents shift-
ing the vehicle out of Park unless the ignition lock
cylinder is in the Unlock, Run or Start position. In
addition, the operator cannot rotate the key to the
lock position unless the shifter is in the park posi-
tion. On vehicles equipped with floor shift refer to
the - Transaxle for Automatic Transmission Shifter/
Ignition Interlock.
REMOVAL
(1) Disconnect negative (ground) cable from the
battery and isolate cable from battery terminal.
(2) Remove the screws attaching the lower steer-
ing column cover to the instrument panel (Fig. 17),
then remove the cover from the lower instrument
panel.
Fig. 15 Ignition Switch Connectors
1 - KEY IN SWITCH
2 - PRNDL SWITCH
3 - IGNITION SWITCH
Fig. 16 Ignition Switch Installation
1 - IGNITION SWITCH
2 - ACTUATOR SHAFT
3 - RETAINING TABS
Fig. 17 Lower Steering Column Cover Attachment
1 - PARK BRAKE RELEASE HANDLE
2 - STEERING COLUMN COVER
3 - STEERING COLUMN
4 - ATTACHING CLIP
5 - ATTACHING SCREWS
6 - HOOD RELEASE LEVER
7 - ATTACHING SCREWS
RSCOLUMN19-17
IGNITION SWITCH (Continued)
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(3) Remove the parking brake release cable from
the parking brake release lever (Fig. 18), then move
the lower steering column cover out of the way.
(4)
Remove the 10 bolts attaching the lower steering
column cover liner to the instrument panel (Fig. 19),
then remove the lower steering column cover liner.
(5) Remove the 3 screws attaching the upper and
lower shrouds to the steering column (Fig. 20), then
separate and remove both shrouds.(6) Remove the trim bezel on the instrument panel
above the steering column. The trim bezel is
mounted to the instrument panel using 2 screws (one
on each side of the column) and retaining clips.
(7) Remove the 2 screws securing the steering col-
umn fixed shroud to the steering column (Fig. 21),
then remove the shroud.
Fig. 18 Parking Brake Release Cable Attachment To
Release Lever
1 - PARK BRAKE PEDAL RELEASE CABLE
2 - PARK BRAKE RELEASE LEVER
3 - LOWER STEERING COLUMN COVER
Fig. 19 Liner Attachment
1 - STEERING COLUMN COVER LINER
2 - ATTACHING BOLTS
3 - ATTACHING BOLTS
4 - STEERING COLUMN
5 - ATTACHING BOLTS
6 - ATTACHING BOLTS
Fig. 20 Steering Column Shroud Screws
1 - STEERING WHEEL
2 - SCREWS
3 - LOWER STEERING COLUMN SHROUD
Fig. 21 Fixed Shroud Mounting
1 - SCREWS
2 - SHROUD
19 - 18 COLUMNRS
LOCK CYLINDER HOUSING (Continued)
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(5) Carefully install the ignition switch over the
actuator shaft (Fig. 30) . The switch will snap over
the retaining tabs on the housing.
(6) Install the ignition switch mounting screw (Fig.
26) .
(7) Install the key cylinder halo lamp on the lock
cylinder housing.
(8) Install the vehicle wiring harness connector
onto the key cylinder halo lamp (Fig. 25) .
(9) Install the key cylinder (with key in it turned
to the ON position) by sliding it straight into the lock
cylinder housing aligning the retaining tab on the
key cylinder with the hole in the lock cylinder hous-
ing.
(10) Turn the key to the OFF position and remove
the key.
(11) Connect the shifter/ignition interlock link to
the lever on the lock cylinder housing by aligning the
retaining tab on the lever with the ramp on the link
(Fig. 23) , then pushing the two together.
(12) Install the metal cover in place below the
shifter/ignition interlock linkage using the two
screws (Fig. 22) .
(13) Install the steering column fixed shroud on
the steering column (Fig. 21) using its 2 mounting
screws.
(14) Install the trim bezel on the instrument panel
above the steering column. The trim bezel is
mounted to the instrument panel using 2 screws (one
on each side of the column) and retaining clips.
(15) Install the lower steering column shroud on
the steering column. Install and securely tighten the
center screw attaching the lower shroud to the tilt
head on the column (Fig. 20) .(16) Install the upper steering column shroud over
the tilt head of the steering column snapping it into
place on the lower shroud. Install and securely
tighten the 2 remaining screws attaching the upper
shroud to the lower shroud (Fig. 20) .
(17) Install the steering column cover liner on the
instrument panel below the steering column (Fig. 19)
. Install and securely tighten the 10 bolts attaching
the steering column cover liner to the instrument
panel.
(18) Install the parking brake pedal release cable
on the parking brake release lever in the lower steer-
ing column cover (Fig. 18) .
(19) Install the lower steering column trim cover
on the instrument panel below the steering column.
Install and securely the screws attaching the lower
steering column cover to the instrument panel (Fig.
17) .
(20) Connect the negative (ground) cable on the
battery terminal.
KEY/LOCK CYLINDER
DESCRIPTION
The lock cylinder is inserted in the end of the
housing opposite the ignition switch.
OPERATION
The ignition key rotates the cylinder to 5 different
detents (Fig. 31) :
²Accessory
²Off (lock)
²Unlock
²On/Run
²Start
Fig. 30 Ignition Switch Installation
1 - IGNITION SWITCH
2 - ACTUATOR SHAFT
3 - RETAINING TABS
Fig. 31 Ignition Lock Cylinder Detents
RSCOLUMN19-21
LOCK CYLINDER HOUSING (Continued)
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ASSEMBLY...........................115
SHIFT INTERLOCK SOLENOID
DESCRIPTION........................115
OPERATION..........................115
DIAGNOSIS AND TESTING - BRAKE/
TRANSMISSION SHIFT INTERLOCK
SOLENOID..........................117
REMOVAL............................117
INSTALLATION........................118
SOLENOID - TCC
DESCRIPTION........................119
OPERATION..........................119
REMOVAL............................119
INSTALLATION........................120
THROTTLE VALVE CABLE
REMOVAL............................120
INSTALLATION........................121
ADJUSTMENTS
THROTTLE VALVE LINKAGE
ADJUSTMENT.......................122
TORQUE CONVERTER
DESCRIPTION........................122
OPERATION..........................126
REMOVAL............................127
INSTALLATION........................127
TRANSFER SYSTEM - OUTPUT SHAFT/GEAR/
BEARING
REMOVAL............................128INSTALLATION........................131
ADJUSTMENTS
ADJUSTMENT - OUTPUT SHAFT BEARING . 135
TRANSFER SYSTEM - TRANSFER SHAFT/
GEAR/BEARING
REMOVAL............................137
INSTALLATION........................141
ADJUSTMENTS
ADJUSTMENT - TRANSFER SHAFT
BEARING...........................145
VALVE BODY
REMOVAL............................146
DISASSEMBLY........................148
CLEANING...........................154
INSPECTION.........................155
ASSEMBLY...........................155
INSTALLATION........................158
ADJUSTMENTS
HYDRAULIC CONTROL PRESSURE
ADJUSTMENTS......................160
VEHICLE SPEED SENSOR/PINION GEAR
REMOVAL............................160
INSTALLATION........................160
31TH AUTOMATIC
TRANSAXLE
DESCRIPTION
This transaxle combines torque converter, three
speed transmission, final drive gearing, and differen-
tial into a front wheel drive system.
Within this transaxle, there are three primary
areas:
(1) Main center line plus valve body.
(2) Transfer shaft center line (includes governor
and parking sprag).
(3) Differential center line.
Center distances between the main rotating parts
in these three areas are held precise to maintain a
low noise level.
The torque converter, transaxle area, and differen-
tial are housed in an integral aluminum die casting.
The differential oil sump is common with the
transaxle sump. Separate filling of the differen-
tial is NOT necessary.
The torque converter is attached to the crankshaft
through a flexible driving plate. Cooling of the con-
verter is accomplished by circulating the transaxle
fluid through a remote cooler. There are two types of
coolers used. An oil-to-water type cooler located in
the radiator side tank and/or an oil-to-air heatexchanger. The torque converter assembly is a sealed
unit that cannot be disassembled.
The transaxle fluid is filtered by an internal filter
attached to the lower side of the valve body assembly.
Engine torque is transmitted to the torque con-
verter and then through the input shaft to multiple-
disc clutches in the transaxle. The power flow
depends on the application of the clutches and bands.
Refer to Elements in Use Chart in Diagnosis and
Tests section.
The transaxle consists of:
²Two multiple-disc clutches
²An overrunning clutch
²Two servos
²A hydraulic accumulator
²Two bands
²Two planetary gear sets
This provides three forward ratios and a reverse
ratio. The common sun gear of the planetary gear
sets is connected to the front clutch by a driving
shell. The driving shell is splined to the sun gear and
front clutch retainer. The hydraulic system consists
of an oil pump and a single valve body which con-
tains all of the valves except the governor valves.
The transaxle sump and differential sump are both
vented through the dipstick. Output torque from the
main center line is delivered through helical gears to
the transfer shaft. This gear set is a factor in the
transaxle final drive (axle) ratio. The shaft also car-
21 - 22 31TH AUTOMATIC TRANSAXLERS
ProCarManuals.com
(8) Start engine and allow to idle for at least one
minute. Then, with parking and service brakes
applied, move selector lever momentarily to each
position, ending in the park or neutral position.
(9) Check the transaxle fluid level and add an
appropriate amount to bring the transaxle fluid level
to 3mm (1/8 in.) below the ªADDº mark on the dip-
stick (Fig. 168).
(10) Recheck the fluid level after the transaxle has
reached normal operating temperature (180ÉF.).
(Refer to 21 - TRANSMISSION/TRANSAXLE/AUTO-
MATIC - 31TH/FLUID - STANDARD PROCEDURE)(11) To prevent dirt from entering transaxle, make
certain that dipstick is fully seated into the dipstick
opening.
DIPSTICK TUBE FLUID SUCTION METHOD
(ALTERNATIVE)
(1) When performing the fluid suction method,
make sure the transaxle is at full operating temper-
ature.
(2) To perform the dipstick tube fluid suction
method, use a suitable fluid suction device (VaculaŸ
or equivalent).
(3) Insert the fluid suction line into the dipstick
tube.
NOTE: Verify that the suction line is inserted to the
lowest point of the transaxle oil pan. This will
ensure complete evacuation of the fluid in the pan.
(4) Follow the manufacturers recommended proce-
dure and evacuate the fluid from the transaxle.
(5) Remove the suction line from the dipstick tube.
(6) Pour four quarts of MopartATF+4 (Automatic
Transmission FluidÐType 9602) through the dipstick
opening.
(7) Start engine and allow to idle for at least one
minute. Then, with parking and service brakes
applied, move selector lever momentarily to each
position, ending in the park or neutral position.
(8) Check the transaxle fluid level and add an
appropriate amount to bring the transaxle fluid level
to 3mm (1/8 in.) below the ªADDº mark on the dip-
stick (Fig. 168).
(9) Recheck the fluid level after the transaxle has
reached normal operating temperature (180ÉF.).
(Refer to 21 - TRANSMISSION/TRANSAXLE/AUTO-
MATIC - 31TH/FLUID - STANDARD PROCEDURE)
(10) To prevent dirt from entering transaxle, make
certain that dipstick is fully seated into the dipstick
opening.
Fig. 166 Oil Filter Screws
1 - SCREWDRIVER HANDLE
2 - SPECIAL TOOL L-4553
3 - OIL FILTER SCREWS (2)
4 - OIL FILTER
Fig. 167 Oil Filter and Gasket
1 - OIL FILTER
2 - GASKET
3 - VALVE BODY
Fig. 168 Dipstick Markings
1 - TRANSAXLE DIPSTICK
21 - 100 31TH AUTOMATIC TRANSAXLERS
FLUID (Continued)
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ADJUSTMENTS
GEARSHIFT CABLE ADJUSTMENT
Lift and rotate the gearshift hand lever into the
park (P) gate position and remove the ignition key.
This confirms the shift lever is in the gated park (P)
position.
After confirming the park gate position, turn the
ignition switch . If the starter will operate, the park
gate position is correct. Move the shift lever into the
neutral (N) position. If the starter will operate in this
position, the linkage is properly adjusted. If the
starter fails to operate in either position, linkage
adjustment is required.
(1) Park the vehicle on level ground and set the
parking brake.
(2) Place the gearshift lever in park (P) gate posi-
tion and remove key.
(3) Loosen the cable adjustment screw at the
transaxle operating lever (Fig. 181).
(4) Pull the transaxle operating lever fully forward
to the park detent position.
(5) Release the park brake, then rock the vehicle
to assure it is in park lock. Reset the park brake.
(6) Tighten the cable adjustment screw to 8 N´m
(70 in. lbs.). Gearshift cable should now be properly
adjusted.
(7) Verify PRNDL indicator still displays the corre-
sponding gear completely. If not, readjustment of
PRNDL may be required.
(8) Check adjustment by using the preceding pro-
cedure.
GOVERNOR
DESCRIPTION
The governor assembly is fastened to the transaxle
transfer shaft. It consists of a governor body, weight,
valve, and shaft.
OPERATION
The governor meters hydraulic pressure, and this
metered pressure is used to signal the transmission
when it is time for a shift to occur. It does this by
balancing governor pressure on one side of a shift
valve, and throttle pressure on the other. When gov-
ernor pressure increases far enough to overcome the
throttle pressure on the valve, a shift occurs.
With the gearshift selector in a forward driving
range, line pressure flows from the manual valve and
down to the governor valve. When the output shaft
starts to rotate with vehicle motion, the governor
weight assembly will start to move outward due to
centrifugal force. As the weight is moved outward, it
will pull the valve with it until the land of the valve
uncovers the line pressure port. As the port begins to
become uncovered, governor pressure is metered. As
the vehicle's speed continues to increase, the weight
assembly will be at a point at which governor pres-
sure is acting on the left side of the reaction area of
the valve. This produces sufficient force to compress
the spring and allow the outer weight to move out
against the outer governor body retaining ring. At a
very high speed, the governor valve will be opened as
far as possible. In this condition, it is possible for
governor pressure to meet, but not to exceed, line
pressure. Generally governor pressure ranges from
0-100 psi from idle to maximum speed, and rises pro-
portionally with the increase in output shaft speed.
Governor pressure and throttle pressure are acting
upon the shift valves to determine when a shift will
occur. Governor pressure is a direct indication of road
speed, and throttle pressure is an indication of
engine load. When both parameters have been met
by the throttle and governor pressures, an upshift or
downshift will occur.
CLEANING
Thoroughly clean all the governor parts in a suit-
able cleaning solution but do not use any type of
caustic cleaning agents.
The governor weight components and the governor
valve, must slide freely in their bores when clean and
dry. Minor surface scratches and burrs can be
smoothed with crocus cloth.
INSPECTION
The aluminum governor valve and outer weight
have a hard coating on them. Check condition of this
Fig. 181 Gearshift Cable Adjustment
1 - SHIFT CABLE ADJUSTMENT
2 - SHIFT CABLE
21 - 104 31TH AUTOMATIC TRANSAXLERS
ProCarManuals.com
ASSEMBLY
(1) Install low/reverse servo assembly (Fig. 208).
(2) Install low/reverse servo snap ring (Fig. 205).
SHIFT INTERLOCK SOLENOID
DESCRIPTION
The Brake/Transmission Shift Interlock system
consists of an electro-magnetic solenoid mounted to
the steering column (Fig. 209). The solenoid's plunger
consists of an integrated hook, which operates the
shift lever pawl (part of shift lever assembly), and a
plunger return spring (Fig. 210). The solenoid also
has an integrated bracket, which facilitates fastening
to the steering column.
OPERATION
The Brake/Transmission Shift Interlock (BTSI)
Solenoid prevents the transmission shift lever from
being moved out of PARK (P) unless the brake pedal
is applied. The BTSI solenoid is hardwired to and
controlled by the Intelligent Power Module (IPM).
Battery voltage is applied to one side of the solenoid
with the ignition key is in either the OFF, ON/RUN,
or START positions (Fig. 211). The ground side of the
solenoid is controlled by a driver within the IPM. It
relies on voltage supplied from the stop lamp switch
to the stop lamp sense circuit within the IPM to tell
when the brake pedal is depressed. When the brake
pedal is depressed, the ground circuit opens, de-ener-
gizing the solenoid. When the brake pedal is
released, the ground circuit is closed, energizing the
solenoid.
Fig. 208 Low/Reverse Servo Assembly
1 - SERVO PISTON
2 - SPRINGFig. 209 Brake/Transmission Shift Interlock (BTSI)
Solenoid Location
1 - BTSI SOLENOID
Fig. 210 Solenoid Plunger and Return Spring
1 - PLUNGER
2 - RETURN SPRING
3 - BTSI SOLENOID
RS31TH AUTOMATIC TRANSAXLE21 - 115
SERVO - LOW/REVERSE (Continued)
ProCarManuals.com
When the ignition key is in either the OFF,
ON/RUN, or START positions, the BTSI solenoid is
energized, and the solenoid plunger hook pulls the
shift lever pawl into position, prohibiting the shift
lever from moving out of PARK (P) (Fig. 212). When
the brake pedal is depressed, the ground circuit
opens, de-energizing the solenoid. This moves the
gearshift lever pawl out of the way (Fig. 213), allow-
ing the shift lever to be moved into any gear position.A conventional mechanical interlock system is also
used. This system manually prohibits shifter move-
ment when the ignition switch is in the LOCK or
ACC positions. Solenoid operation is not required in
these key positions.
For intended BTSI system operation, refer to the
following chart:
ACTION EXPECTED RESPONSE
1. Turn key to the9OFF9
position.1. Shifter CAN be shifted
out of park with brake
pedal applied.
2. Turn key to the
9ON/RUN9position.2. Shifter CANNOT be
shifted out of park.
3. Turn key to the
9ON/RUN9position 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 the9LOCK9or9ACC9
position.4. Key cannot be
returned to the9LOCK9or
9ACC9position.
5. Return shifter to
9PARK9and try to remove
the key.5. Key can be removed
(after returning to9LOCK9
position).
6. With the key removed,
try to shift out of9PARK9.6. Shifter cannot be
shifted out of9PARK9.
NOTE: Any failure to meet these expected
responses requires system adjustment or repair.
Fig. 211 Ignition Key/Switch Positions
1 - ACC
2 - LOCK
3 - OFF
4 - ON/RUN
5-START
Fig. 212 Pawl Engaged to Shift Lever
1 - GEAR SHIFT LEVER
2 - GEAR SHIFT LEVER PAWL
Fig. 213 Pawl Disengaged From Shift Lever
1 - GEAR SHIFT LEVER
2 - GEAR SHIFT LEVER PAWL
21 - 116 31TH AUTOMATIC TRANSAXLERS
SHIFT INTERLOCK SOLENOID (Continued)
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