brake DODGE NEON 2000 Service Repair Manual

(23) Remove the shift blocker assembly from the
bench fixture (Fig. 71).
(24) Remove the 1-2 shift fork from the output
shaft (Fig. 72).
(25) Remove input and output shaft assemblies
from bench fixture (Fig. 73).CAUTION: The output shaft assembly is serviced
as an assembly. Do not try to repair any component
on the output shaft. If the 1-2 synchronizer or gear
fails, it is necessary to replace the complete output
shaft assembly.
Fig. 70 Reverse Brake Race
1 ± REVERSE BRAKE RACE
Fig. 71 Shift Blocker Removal
1 ± 6785 BENCH FIXTURE
2 ± SHIFT BLOCKER ASSEMBLY
Fig. 72 1±2 Shift Fork Removal
1 ± 6785 BENCH FIXTURE
2 ± 1±2 SHIFT FORK
Fig. 73 Gear Train Removal
1 ± 6785 BENCH FIXTURE
2 ± INPUT AND OUTPUT SHAFTS
21 - 24 TRANSAXLEPL
DISASSEMBLY AND ASSEMBLY (Continued)

ASSEMBLY
The sealant used to seal the transaxle case halves
is MopartGasket Maker, Loctitet518, or equivalent.
The sealant used for the bearing end plate cover is
MopartRTV.
(1) Verify bench fixture shims are removed from
bench fixture. Install output and input shafts into
bench fixture (Miller tool #6785) (Fig. 74).
(2) Install shift rails and forks into bench fixture
(Fig. 75).
(3) Install shift blocker assembly into bench fix-
ture (Fig. 76).
(4) Install reverse brake race onto input shaft (Fig.
77).
(5) Install reverse brake needle bearing (Fig. 78).
Fig. 74 Bench Fixture
1 ± BENCH FIXTURE
2 ± GEARTRAIN
Fig. 75 Shift Rail Installation
1 ± 6785 BENCH FIXTURE
2 ± 1±2 SHIFT FORK
Fig. 76 Shift Blocker Installation
1 ± 6785 BENCH FIXTURE
2 ± SHIFT BLOCKER ASSEMBLY
Fig. 77 Reverse Brake Race Installation
1 ± REVERSE BRAKE RACE
Fig. 78 Reverse Brake Needle Bearing
1 ± REVERSE BRAKE NEEDLE BEARING
PLTRANSAXLE 21 - 25
DISASSEMBLY AND ASSEMBLY (Continued)

(6) Install reverse brake blocking ring (Fig. 79).
(7) Install reverse brake friction cone (Fig. 80).(8) Install reverse brake shim (Fig. 81). Apply
petroleum jelly to shim to hold in place.
(9) Install gear±case half over bench fixture (Fig.
82). Line up shift finger over 3-4 lug.
Fig. 79 Reverse Brake Blocking Ring Installation
1 ± REVERSE BRAKE BLOCKING RING
Fig. 80 Reverse Brake Friction Cone Installation
1 ± REVERSE BRAKE FRICTION CONE
Fig. 81 Reverse Brake Shim
1 ± REVERSE BRAKE SHIM
2 ± REVERSE BRAKE FRICTION CONE
Fig. 82 Gear Case Half
1 ± TRANSAXLE CASE
2 ± BENCH FIXTURE
3 ± GEARTRAIN
21 - 26 TRANSAXLEPL
DISASSEMBLY AND ASSEMBLY (Continued)

(10) Line up reverse brake friction cone lugs to the
slots in the gear case (Fig. 83). Verify reverse brake
shim is in position.
(11) Position input and output bearings on the
shafts. Using Miller tool C-4992-1, press on input
and output shaft bearings until they bottom into the
case and against the shafts (Fig. 84).(12) Install shaft snap rings at input and output
bearings (Fig. 85).
(13) Apply MopartRTV sealant to end±cover outer
edge and around bolt holes. Install end±cover onto
gear case. Tighten end cover bolts to 29 N´m (21 ft.
lbs.) torque (Fig. 86).
Fig. 83 Friction Cone Lugs
1 ± CASE
2 ± FRICTION CONE LUGS
3 ± INPUT SHAFT
Fig. 84 Installing Input and Output Bearings
1 ± INPUT AND OUTPUT BEARINGS
2 ± SPECIAL TOOL C-4992-1
Fig. 85 Snap Rings Retaining Bearings
1 ± SNAP RING PLIERS
2 ± SNAP RINGS
Fig. 86 Transaxle End Cover
1 ± TRANSAXLE CASE
2 ± END COVER
PLTRANSAXLE 21 - 27
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

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)

LOW AND REVERSE SERVO (REAR)
Direct air pressure into LOW/REVERSE SERVO
APPLY passage. Operation of servo is indicated by a
tightening of rear band. Spring tension on servo pis-
ton should release the band.
If clutches and servos operate properly, no upshift
indicates that a malfunction exists in the valve body.
FLUID LEAKAGE-TRANSAXLE TORQUE
CONVERTER HOUSING AREA
(1) Check for source of leakage.
(2) Since fluid leakage near the torque converter
area may be from an engine oil leak, the area should
be checked closely. Factory fill fluid is dyed red and,
therefore, can be distinguished from engine oil.
(3) Prior to removing the transaxle, perform the
following checks:
(4) When leakage is determined to originate from
the transaxle, check fluid level prior to removal of
the transaxle and torque converter.
(5) High oil level can result in oil leakage out the
vent in the dipstick. If the fluid level is high, adjust
to proper level.
(6) After performing this operation, inspect for
leakage. If a leak persists, perform the following
operation on the vehicle. This will determine if the
torque converter or transaxle is leaking.
TORQUE CONVERTER LEAKAGE
Possible sources of torque converter leakage are:
²Torque converter weld leaks at the outside diam-
eter (peripheral) weld
²Torque converter hub weld
²Torque converter impeller shell cracked adjacent
to hub
²At drive lug welds
NOTE: Hub weld is inside and not visible. Do not
attempt to repair. Replace torque converter.
BRAKE TRANSMISSION SHIFT INTERLOCK
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. Refer to Brake Transmission Interlock
Removal and Installation or Adjustment in this
Group.
SERVICE PROCEDURES
TRANSAXLE FLUID AND FILTER SERVICE
NOTE: Refer to Group 0, Lubrication and Mainte-
nance, or the vehicle owner's manual, for the rec-
ommended maintenance (fluid/filter change)
intervals for this transaxle.
NOTE: Only fluids of the type labeled MoparT
ATF+4 (Automatic Transmission Fluid) Type 9602
should be used. A filter change should be made at
the time of the transmission oil change. The magnet
(on the inside of the oil pan) should also be cleaned
with a clean, dry cloth.
NOTE: If the transaxle is disassembled for any rea-
son, the fluid and filter should be changed.
FLUID/FILTER SERVICE (RECOMMENDED)
(1) Raise vehicle on a hoist (See Lubrication,
Group 0). Place a drain container with a large open-
ing, under transaxle oil pan.
(2) Loosen pan bolts and tap the pan at one corner
to break it loose allowing fluid to drain, then remove
the oil pan.
(3) Install a new filter and o-ring on bottom of the
valve body and tighten retaining screws to 5 N´m (40
in. lbs.).
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.
21 - 70 TRANSAXLEPL
DIAGNOSIS AND TESTING (Continued)

(4) Clean the oil pan and magnet. Reinstall pan
using new Mopar Silicone Adhesive sealant. Tighten
oil pan bolts to 19 N´m (165 in. lbs.).
(5) Pour four quarts of MopartATF+4 (Automatic
Transmission Fluid) Type 9602 through the dipstick
opening.
(6) 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.
(7) 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. 8).
(8) Recheck the fluid level after the transaxle has
reached normal operating temperature (180ÉF.).
(9) To prevent dirt from entering transaxle, make
certain that dipstick is fully seated into the dipstick
opening.
ALTERNATIVE MAINTENANCE METHODS
TRANSAXLE FLUID EXCHANGER METHOD
CAUTION: The use of any fluid exchanger that
introduces additives into the transaxle is not rec-
ommended.
(1) To perform the transaxle fluid exchange, the
transaxle must be at operating temperature. Drive
the vehicle until it reaches full operating tempera-
ture.
(2) Obtain a suitable transaxle fluid exchanger
and verify the tank is clean and dry.
(3) Fill the tank to the recommended fill capacity
with MopartATF+4 Type 9602.
(4) Connect the machine to the vehicle following
the manufacturers instructions. Perform the
exchange procedure following the instructions pro-
vided with the machine.(5) Once machine has completed the fluid
exchange. Check the fluid level and condition and fill
to proper level with MopartATF+4 Type 9602. Refer
to Fluid Level and Condition Check in this group for
the proper fluid ªtop-offº procedure.
NOTE: Verify that the transaxle cooler lines are
tightened to proper specifications. Cooler line
torque specification is 2 N²m (18 in. lbs.).
DIPSTICK TUBE FLUID SUCTION METHOD
(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 (Vaculay
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 Fluid) Type 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. 8).
(9) Recheck the fluid level after the transaxle has
reached normal operating temperature (180ÉF.).
(10) To prevent dirt from entering transaxle, make
certain that dipstick is fully seated into the dipstick
opening.
ALUMINUM THREAD REPAIR
Damaged or worn threads in the aluminum tran-
saxle case and valve body can be repaired by the use
of Heli-Coils. This repair consists of drilling out the
worn-out or damaged threads. Then tap the hole with
a Heli-Coil tap, and install a Heli-Coil insert into the
hole. This brings the hole back to its original thread
size.
Heli-Coil tools and inserts are readily available
from most automotive parts suppliers.
Fig. 8 Dipstick Markings
1 ± TRANSAXLE DIPSTICK
PLTRANSAXLE 21 - 71
SERVICE PROCEDURES (Continued)

(1) Verify cable is routed properly with no kinked
or binding conditions.
(2) Release adjustment locking clip on cable at
throttle body.It is not necessary to remove clip.
(3) Grab cable conduit near adjustment body, push
in towards throttle body, then release grip (Fig. 27).
This allows cable to self adjust.
(4) Press locking clip to secure cable position (Fig.
28).
(5) Road test vehicle to verify proper transaxle
operation.BRAKE TRANSMISSION SHIFT INTERLOCK
CABLE
REMOVAL
(1) Disconnect the battery negative cable.
(2) Loosen set screw and remove knob from shifter
handle (Fig. 29).
(3) Remove the center console assembly as shown
in (Fig. 30).
Fig. 27 Throttle Valve Cable Adjustment
1 ± TAB UNLOCKED
Fig. 28 Cable Locking Clip
1 ± TAB LOCKED
2 ± THROTTLE VALVE CABLE
Fig. 29 Gearshift Knob Removal/Installation
1 ± SHIFTER KNOB
2 ± SET SCREW
Fig. 30 Center Console Removal/Installation
1 ± CONSOLE
2 ± SCREW (4)
3 ± SCREW (2)
PLTRANSAXLE 21 - 79
REMOVAL AND INSTALLATION (Continued)

(4) Remove shifter bezel (Fig. 31).
(5) Disconnect the shifter/ignition interlock cable
from the shifter lever and bracket as shown in (Fig.
32). Remove the cable core end from the plastic cam
of the shifter mechanism and release cable from
shifter bracket
(6) Remove the steering column lower cover (Fig.
33).
(7) Remove the steering column upper and lower
shrouds (Fig. 34).(8) Disconnect the Brake Transmission Shift Inter-
lock (BTSI) solenoid connector from the interlock
cable (Fig. 35).
(9) Rotate the ignition key to the ªOFFº or ªON/
RUNº position (Fig. 36).
(10) Squeeze the interlock cable locking tab.
Remove the cable from the interlock housing (Fig.
37).
(11) Release cable from retaining clips and remove
through opening under steering column.
Fig. 31 Shifter Bezel Removal/Installation
1 ± BEZEL
2 ± SCREW (4)
Fig. 32 Interlock Cable at Shifter Assembly
1 ± INTERLOCK CABLE
2 ± SHIFTER ASSEMBLY
Fig. 33 Steering Column Lower Cover
1 ± LOWER COVER
Fig. 34 Steering Column Shrouds
1 ± UPPER SHROUD
2 ± LOWER SHROUD
21 - 80 TRANSAXLEPL
REMOVAL AND INSTALLATION (Continued)