31th DODGE TOWN AND COUNTRY 2001 User Guide

FLEX PLATE
REMOVAL
(1) Remove the transaxle. (Refer to 21 - TRANS-
MISSION/TRANSAXLE/AUTOMATIC - 31TH -
REMOVAL) (Refer to 21 - TRANSMISSION/TRAN-
SAXLE/AUTOMATIC - 41TE - REMOVAL)
(2) Remove flex plate attaching bolts.
(3) Remove the flex plate (Fig. 68).
INSTALLATION
(1) Position flex plate with backing plate on the
crankshaft (Fig. 68).
(2) Apply MopartLock & Seal Adhesive to the flex
plate bolts.
(3) Install flex plate bolts (Fig. 68). Tighten bolts
to 95 N´m (70 ft. lbs.).
(4) Install the transaxle. (Refer to 21 - TRANS-
MISSION/TRANSAXLE/AUTOMATIC - 31TH -
INSTALLATION) (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 41TE - INSTALLA-
TION)
HYDRAULIC LIFTERS (CAM IN
BLOCK)
DESCRIPTION
The hydraulic lifters are a roller type design and
are positioned in the cylinder block. The lifters are
aligned and retained by a yoke and a retainer (Fig.
69).
Lifter alignment is maintained by machined flats
on lifter body. Lifters are fitted in pairs into sixaligning yokes. The aligning yokes are secured by a
yoke retainer (Fig. 69).
DIAGNOSIS AND TESTING - HYDRAULIC
LIFTERS
HYDRAULIC LIFTERS DIAGNOSIS - PRELIMINARY
STEP
Before disassembling any part of the engine to cor-
rect lifter noise, check the engine oil pressure. (Refer
to 9 - ENGINE/LUBRICATION - DIAGNOSIS AND
TESTING)
Check engine oil level. The oil level in the pan
should never be above the MAX mark on dipstick, or
below the MIN mark. Either of these two conditions
could cause noisy lifters.
Fig. 68 FLEX PLATE
1 - FLEX PLATE
2 - BOLT (QTY. 8)
3 - BACKING PLATE
Fig. 69 Hydraulic Lifters
1 - YOKE RETAINER
2 - BOLT - YOKE RETAINER
3 - ALIGNING YOKE
4 - HYDRAULIC LIFTER
9 - 118 ENGINE 3.3/3.8LRS
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REAR MOUNT
REMOVAL
(1) Raise vehicle on hoist.
(2) Remove the rear mount heat shield (Fig. 94).
Fig. 91 LEFT MOUNT TO BRACKET
1 - BOLT - BRACKET TO FRAME RAIL 68 N´m (50 ft. lbs.)
2 - BOLT - MOUNT TO RAIL THRU 75 N´m (55 ft. lbs.)
3 - BOLT - LEFT MOUNT TO TRANSAXLE 54 N´m (40 ft. lbs.)
4 - TRANSAXLE
5 - MOUNT - LEFT
6 - BRACKET - LEFT MOUNT
Fig. 92 LEFT MOUNT - 31TH TRANSAXLE
1 - LEFT MOUNT ASEMBLY
2 - BOLT - 54 N´m (40 ft. lbs.)
3 - TRANSAXLE - 31TH
Fig. 93 LEFT MOUNT - 41TE TRANSAXLE
1 - LEFT MOUNT ASSEMBLY
2 - BOLT - 54 N´m (40 ft. lbs.)
3 - TRANSAXLE - 41TE
Fig. 94 REAR MOUNT HEAT SHIELD
1 - BOLT - HEAT SHIELD 11 N´m (100 in. lbs.)
2 - HEAT SHIELD
3 - CLIP
4 - REAR MOUNT
RSENGINE 3.3/3.8L9 - 129
LEFT MOUNT (Continued)
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TRANSMISSION/TRANSAXLE
TABLE OF CONTENTS
page page
POWER TRANSFER UNIT...................1
AUTOMATIC - 31TH.......................21AUTOMATIC - 41TE......................158
POWER TRANSFER UNIT
TABLE OF CONTENTS
page page
POWER TRANSFER UNIT
DESCRIPTION............................1
OPERATION.............................3
DIAGNOSIS AND TESTING..................3
SEAL IDENTIFICATION...................3
FLUID LEAK DIAGNOSIS..................3
STANDARD PROCEDURE...................4
FLUID LEVEL INSPECTION................4
PTU FLUID CHANGE.....................4
REMOVAL...............................5
INSTALLATION............................6
ADJUSTMENTS...........................7
SPECIFICATIONS.........................7
SPECIAL TOOLS..........................8
DIFFERENTIAL CARRIER SEAL
REMOVAL...............................9
INSTALLATION............................9
END COVER BALL BEARING
REMOVAL...............................9
INSTALLATION...........................10
END COVER SEAL
REMOVAL..............................11INSTALLATION...........................11
HALF SHAFT INNER SEAL
REMOVAL..............................12
INSTALLATION...........................12
INPUT SHAFT COVER SEAL
REMOVAL..............................13
INSTALLATION...........................14
INPUT SHAFT END SEAL
REMOVAL..............................16
INSTALLATION...........................16
INPUT SHAFT SEAL
REMOVAL..............................17
INSTALLATION...........................18
OUTER HALF SHAFT SEAL
REMOVAL..............................18
INSTALLATION...........................19
REAR COVER O-RING
REMOVAL..............................20
INSTALLATION...........................20
POWER TRANSFER UNIT
DESCRIPTION
The Power Transfer Unit (P.T.U.) is attached to a
modified automatic transaxle case where the right
half shaft extension housing would normally be
located.
The Power Transfer Unit is sealed from the trans-
axle and has its own oil sump. The Unit uses
Moparž SAE 80W-90 Gear and Axle Lubricant (MS-
9020) and holds 1.15 liters (1.22 quarts).Service of the Power Transfer Unit is limited to:
²Fluid Change
²Seals
²Gaskets
²One ball bearing
²Output flange
If the ring gear and pinion, any tapered roller
bearings, case, covers, or pinion carrier fail the entire
unit must be replaced.
RSTRANSMISSION/TRANSAXLE21-1
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AUTOMATIC - 31TH
TABLE OF CONTENTS
page page
AUTOMATIC - 31TH
DESCRIPTION...........................22
OPERATION.............................24
DIAGNOSIS AND TESTING.................24
PRELIMINARY DIAGNOSIS...............24
ROAD TEST...........................31
HYDRAULIC PRESSURE TESTS...........32
TORQUE CONVERTER HOUSING FLUID
LEAKAGE.............................34
CLUTCH AND SERVO AIR PRESSURE
TESTS...............................35
STANDARD PROCEDURE..................36
ALUMINUM THREAD REPAIR.............36
REMOVAL..............................36
DISASSEMBLY...........................39
ASSEMBLY.............................50
INSTALLATION...........................59
SCHEMATICS AND DIAGRAMS..............63
SPECIFICATIONS........................71
SPECIAL TOOLS.........................74
ACCUMULATOR
DESCRIPTION...........................78
OPERATION.............................78
BANDS
DESCRIPTION...........................79
OPERATION.............................79
ADJUSTMENTS..........................79
CLUTCH - FRONT
DESCRIPTION...........................80
OPERATION.............................81
DISASSEMBLY...........................81
ASSEMBLY.............................84
CLUTCH - REAR
DESCRIPTION...........................85
OPERATION.............................85
DISASSEMBLY...........................86
ASSEMBLY.............................89
FINAL DRIVE
DISASSEMBLY...........................90
ASSEMBLY.............................94
ADJUSTMENTS..........................96
FLUID
STANDARD PROCEDURE..................98
FLUID LEVEL AND CONDITION CHECK......98
FLUID AND FILTER CHANGE..............98
GEAR SHIFT CABLE
REMOVAL.............................100
INSTALLATION..........................101
ADJUSTMENTS.........................103GOVERNOR
DESCRIPTION..........................103
OPERATION............................103
CLEANING.............................104
INSPECTION...........................104
OIL PUMP
DESCRIPTION..........................104
OPERATION............................104
STANDARD PROCEDURE.................105
OIL PUMP VOLUME CHECK..............105
DISASSEMBLY..........................105
CLEANING.............................105
INSPECTION...........................105
ASSEMBLY............................105
PARK/NEUTRAL POSITION SWITCH
DIAGNOSIS AND TESTING................106
PARK/NEUTRAL POSITION SWITCH.......106
REMOVAL.............................106
INSTALLATION..........................107
PLANETARY GEARTRAIN
DISASSEMBLY..........................107
ASSEMBLY............................107
SEAL - OIL PUMP
REMOVAL.............................109
INSTALLATION..........................109
SERVO - KICKDOWN
DESCRIPTION..........................109
OPERATION............................109
DISASSEMBLY..........................110
CLEANING.............................111
INSPECTION...........................111
ASSEMBLY.............................112
SERVO - LOW/REVERSE
DESCRIPTION..........................112
OPERATION............................112
DISASSEMBLY..........................112
CLEANING.............................113
ASSEMBLY.............................113
SHIFT INTERLOCK SOLENOID
DESCRIPTION..........................113
OPERATION............................114
DIAGNOSIS AND TESTING................115
BRAKE/TRANSMISSION SHIFT INTERLOCK
SOLENOID...........................115
REMOVAL.............................115
INSTALLATION..........................116
SOLENOID - TCC
DESCRIPTION..........................117
OPERATION............................117
RSAUTOMATIC - 31TH21-21
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REMOVAL.............................118
INSTALLATION..........................118
THROTTLE VALVE CABLE
REMOVAL.............................118
INSTALLATION..........................118
ADJUSTMENTS.........................120
TORQUE CONVERTER
DESCRIPTION..........................120
OPERATION............................123
REMOVAL.............................125
INSTALLATION..........................125
TRANSFER SYSTEM - OUTPUT SHAFT/GEAR/
BEARING
REMOVAL.............................126
INSTALLATION..........................129
ADJUSTMENTS.........................132TRANSFER SYSTEM - TRANSFER SHAFT/
GEAR/BEARING
REMOVAL.............................134
INSTALLATION..........................137
ADJUSTMENTS.........................142
VALVE BODY
REMOVAL.............................142
DISASSEMBLY..........................145
CLEANING.............................151
INSPECTION...........................152
ASSEMBLY............................152
INSTALLATION..........................155
ADJUSTMENTS.........................157
VEHICLE SPEED SENSOR/PINION GEAR
REMOVAL.............................157
INSTALLATION..........................157
AUTOMATIC - 31TH
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 heat
exchanger. 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-
ries the governor and parking sprag. An integral heli-
cal gear on the transfer shaft drives the differential
ring gear.
21 - 22 AUTOMATIC - 31THRS
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31TH Automatic Transaxle
1 - TORQUE CONVERTER CLUTCH
2 - TORQUE CONVERTER
3 - OIL PUMP
4 - FRONT CLUTCH
5 - REAR CLUTCH
6 - OVER-RUNNING CLUTCH7 - PLANETARY GEARS
8 - TRANSFER GEARS
9 - TRANSFER SHAFT
10 - GOVERNOR
11 - DIFFERENTIAL
RSAUTOMATIC - 31TH21-23
AUTOMATIC - 31TH (Continued)
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OPERATION
Transmission output is directed to an integral dif-
ferential by a transfer gear system in the following
input-to-output ratios:
FIRST 2.69:1
SECOND 1.55:1
THIRD 1.00:1
REVERSE 2.10:1
DIAGNOSIS AND TESTING - PRELIMINARY
DIAGNOSIS
Automatic transaxle malfunctions are usually
caused by the following general conditions:
²Improper fluid level/condition
²Poor engine performance
²Improper engine or transaxle adjustments
²Transaxle hydraulic malfunctions²Transaxle mechanical malfunctions
Diagnosis of transaxle problems should always
begin with checking the easily accessible variables:
²Fluid level and condition
²Gearshift cable adjustment
²Throttle valve cable adjustment
After verifying or adjusting these variables, road
test the vehicle to determine if the problem has been
corrected or that further diagnosis is necessary. If the
problem still exists, refer to the following diagnosis
charts to aid in determining the source or cause of
failure.
Hydraulic pressure tests should be performed
when a transaxle internal failure is suspected. The
hydraulic flow charts, in the Schematics and Dia-
grams section of this group, outline fluid flow and
hydraulic circuitry. Circuit operation is provided for
all gear ranges. Normal working pressures are also
supplied for each of the gear ranges.
TRANSAXLE DIAGNOSIS CHARTS
CONDITION POSSIBLE CAUSES CORRECTION
HARSH ENGAGEMENT
(FROM NEUTRAL TO
DRIVE OR REVERSE)1. Fluid Level Low 1. Add Fluid
2. Throttle Linkage Misadjusted 2. Adjust linkage - setting may be too
long.
3. Excessive Pinion Backlash 3. Check per Service Manual. Correct as
needed.
4. Hydraulic Pressure Incorrect 4. Check pressure. Remove, overhaul or
adjust valve body as needed.
5. Band Misadjusted. 5. Adjust rear band.
6. Valve Body Check Balls Missing. 6. Inspect valve body for proper check
ball installation.
7. Clutch, band or planetary component
Damaged.7. Remove, disassemble and repair
transmission as necessary.
8. Converter Clutch (if equipped) Faulty. 8. Replace converter and flush cooler and
line before installing new converter.
21 - 24 AUTOMATIC - 31THRS
AUTOMATIC - 31TH (Continued)
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CONDITION POSSIBLE CAUSES CORRECTION
DELAYED
ENGAGEMENT (FROM
NEUTRAL TO DRIVE
OR REVERSE)1. Fluid Level Low . 1. Correct level and check for leaks.
2. Filter Clogged. 2. Change filter.
3. Gearshift Linkage Misadjusted . 3. Adjust linkage and repair linkage if
worn or damaged.
4. Rear Band Misadjusted. 4. Adjust band.
5. Valve Body Filter Plugged. 5. Replace fluid and filter. If oil pan and
old fluid were full of clutch disc material
and/or metal particles, overhaul will be
necessary.
6. Oil Pump Gears Worn/Damaged. 6. Remove transmission and replace oil
pump.
7. Hydraulic Pressure Incorrect. 7. Perform pressure test, remove
transmission and repair as needed.
8. Reaction Shaft Seal Rings Worn/
Broken.8. Remove transmission, remove oil pump
and replace seal rings.
9. Rear Clutch/Input Shaft, Rear Clutch
Seal Rings Damaged.9. Remove and disassemble transmission
and repair as necessary.
10. Governor Valve Stuck. 10. Remove and inspect governor
components. Replace worn or damaged
parts.
11. Regulator Valve Stuck. 11. Clean.
NO DRIVE RANGE
(REVERSE OK)1. Fluid Level Low. 1. Add fluid and check for leaks if drive is
restored.
2. Gearshift Linkage/Cable Loose/
Misadjusted.2. Repair or replace linkage components.
3. Rear Clutch Burnt. 3. Remove and disassemble transmission
and rear clutch and seals. Repair/replace
worn or damaged parts as needed.
4. Valve Body Malfunction. 4. Remove and disassemble valve body.
Replace assembly if any valves or bores
are damaged.
5. Transmission Overrunning Clutch
Broken.5. Remove and disassemble transmission.
Replace overrunning clutch.
6. Input Shaft Seal Rings Worn/Damaged. 6. Remove and disassemble transmission.
Replace seal rings and any other worn or
damaged parts.
7. Front Planetary Failed Broken. 7. Remove and repair.
RSAUTOMATIC - 31TH21-25
AUTOMATIC - 31TH (Continued)
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CONDITION POSSIBLE CAUSES CORRECTION
NO DRIVE OR
REVERSE (VEHICLE
WILL NOT MOVE)1. Fluid Level Low. 1. Add fluid and check for leaks if drive is
restored.
2. Gearshift Linkage/Cable Loose/
Misadjusted.2. Inspect, adjust and reassemble linkage
as needed. Replace worn/damaged parts.
3. Filter Plugged. 3. Remove and disassemble transmission.
Repair or replace failed components as
needed. Replace filter. If filter and fluid
contained clutch material or metal
particles, an overhaul may be necessary.
Perform lube flow test. Flush oil. Replace
cooler as necessary.
4. Oil Pump Damaged. 4. Perform pressure test to confirm low
pressure. Replace pump body assembly if
necessary.
5. Valve Body Malfunctioned. 5. Check press and inspect valve body.
Replace valve body (as assembly) if any
valve or bore is damaged. Clean and
reassemble correctly if all parts are in
good condition.
6. Transmission Internal Component
Damaged.6. Remove and disassemble transmission.
Repair or replace failed components as
needed. Remove and disassemble
transmission. Repair or replace failed
components as needed.
7. Park Sprag not Releasing - Check Stall
Speed, Worn/Damaged/Stuck.7. Remove, disassemble, repair.
8. Torque Converter Damage. 8. Inspect and replace as required.
SHIFTS DELAYED OR
ERRATIC (ALSO
SHIFTS HARSH AT
TIMES)1. Fluid Level Low/High. 1. Correct fluid level and check for leaks if
low.
2. Fluid Filter Clogged. 2. Replace filter. If filter and fluid
contained clutch material or metal
particles, an overhaul may be necessary.
Perform lube flow test.
3. Throttle Linkage Misadjusted. 3. Adjust linkage as described in service
section.
4. Throttle Linkage Binding. 4. Check cable for binding. Check for
return to closed throttle at transmission.
5. Gearshift Linkage/Cable Misadjusted. 5. Adjust linkage/cable as described in
service section.
6. Governor Valve Sticking. 6. Inspect, clean or repair.
7. Governor Seal Rings Worn/Damaged. 7. Inspect/replace.
8. Clutch or Servo Failure. 8. Remove valve body and air test clutch,
and band servo operation. Disassemble
and repair transmission as needed.
9. Front Band Misadjusted. 9. Adjust band.
10. Pump Suction Passage Leak. 10. Check for excessive foam on dipstick
after normal driving. Check for loose
pump bolts, defective gasket. Replace
pump assembly if needed.
21 - 26 AUTOMATIC - 31THRS
AUTOMATIC - 31TH (Continued)
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CONDITION POSSIBLE CAUSES CORRECTION
NO REVERSE (D
RANGES OK)1. Gearshift Linkage/Cable Misadjusted/
Damaged.1. Repair or replace linkage parts as
needed.
2. Rear Band Misadjusted/Worn. 2. Adjust band; replace.
3. Valve Body Malfunction. 3. Remove and service valve body.
Replace valve body if any valves or valve
bores are worn or damaged.
4. Rear Servo Malfunction. 4. Remove and disassemble transmission.
Replace worn/damaged servo parts as
necessary.
5. Direct Clutch in Overdrive Worn 5. Disassemble overdrive. Replace worn
or damaged parts.
6. Front Clutch Burnt. 6. Remove and disassemble transmission.
Replace worn, damaged clutch parts as
required.
HAS FIRST/REVERSE
ONLY (NO 1-2 OR 2-3
UPSHIFT)1. Governor Valve, Shaft, Weights or
Body Damaged/Stuck.1. Remove governor assembly and clean
or repair as necessary.
2. Valve Body Malfunction. 2. Stuck 1-2 shift valve or governor plug.
3. Front Servo/Kickdown Band Damaged/
Burned.3. Repair/replace.
MOVES IN 2ND OR
3RD GEAR, ABRUPTLY
DOWNSHIFTS TO
LOW1. Valve Body Malfunction. 1. Remove, clean and inspect. Look for
stuck 1-2 valve or governor plug.
2. Governor Valve Sticking. 2. Remove, clean and inspect. Replace
faulty parts.
NO LOW GEAR
(MOVES IN 2ND OR
3RD GEAR ONLY)1. Governor Valve Sticking. 1. Remove governor, clean, inspect and
repair as required.
2. Valve Body Malfunction. 2. Remove, clean and inspect. Look for
sticking 1-2 shift valve, 2-3 shift valve,
governor plug or broken springs.
3. Front Servo Piston Cocked in Bore. 3. Inspect servo and repair as required.
4. Front Band Linkage Malfunction 4. Inspect linkage and look for bind in
linkage.
NO KICKDOWN OR
NORMAL DOWNSHIFT1. Throttle Linkage Misadjusted. 1. Adjust linkage.
2. Accelerator Pedal Travel Restricted. 2. Floor mat under pedal, accelerator
cable worn or brackets bent.
3. Governor/Valve Body Hydraulic
Pressures Too High or Too Low Due to
Sticking Governor, Valve Body
Malfunction or Incorrect Hydraulic Control
Pressure Adjustments.3. Perform hydraulic pressure tests to
determine cause and repair as required.
Correct valve body pressure adjustments
as required.
4. Valve Body Malfunction. 4. Perform hydraulic pressure tests to
determine cause and repair as required.
Correct valve body pressure adjustments
as required.
5. Valve Body Malfunction. 5. Sticking 1-2, 2-3 shift valves, governor
plugs, 3-4 solenoid, 3-4 shift valve, 3-4
timing valve.
RSAUTOMATIC - 31TH21-27
AUTOMATIC - 31TH (Continued)
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