2002 CHRYSLER TOWN AND COUNTRY rear differential

OPERATION
The Transfer Unit provides the power to the rear
wheels through a hypoid ring gear and pinion set.
DIAGNOSIS AND TESTING
SEAL IDENTIFICATION
For accurate seal diagnosis, repair seal name and
location is critical. Refer to (Fig. 1), (Fig. 2), (Fig. 3)
and (Fig. 4) for correct seal name and location.
1 - PLUG 18 - CASE-PTU 35 - SHIM
2 - WASHER FLAT 19 - PINION-PTU 36 - TAPERED ROLLER BEARING
3 - SEAL RING 20 - O-RING 37 - SHAFT ASSY. FRONT L.H.
4 - SNAP RING 21 - SHIM 38 - SEAL RING
5 - BALL BEARING 22 - TAPERED ROLLER BEARING 39 - OIL WIPER
6 - SEAL RING 23 - COVER-PTU CASE REAR 40 - RETAINER DIFFERENTIAL BEARING
7 - COVER-PTU
CASE END24 - FLANGE TUBE-PTU-OUTPUT ASSY. 41 - SHAFT DIFFERENTIAL PINION
8 - TAPERED ROLLER BEARING 25 - LOCK NUT-HEX FLANGE 42 - PIN
9 - SEAL RING 26 - O- RING 43 - CASE DIFFERENTIAL
10 - SEAL RING 27 - RETAINER PLATE 44 - TAPERED ROLLER BEARING CONE
11 - HEX HEAD SCREW 28 - O-RING 45 - SEAL RING
12 - SHAFT-PTU INPUT 29 - BRACKET 46 - SEAL RING
13 - GEAR-PTU RING 30 - THRUST WASHER 47 - PLUG
14 - TROUGH-PTU (RT.) 31 - SIDE GEAR-DIFFERENTIAL 48 - O-RING
15 - TROUGH-PTU (LT.) 32 - FINAL DRIVE GEAR 49 - SHIM
16 - TAPERED ROLLER BEARING 33 - PINION DIFFERENTIAL 50 - MAGNET
17 - HEX HEAD SCREW 34 - WASHER DIFFERENTIAL PINION 51 - DOWEL
52 - SHAFT ASSY. FRONT R.H.
53 - HEX HEAD SCREW
Fig. 1 Seal
1 - INPUT SHAFT
2 - P.T.U. CASE
3 - MAGNET
4 - INPUT SHAFT END SEAL
5 - OUTPUT SHAFT
6 - RING GEAR
7 - REAR COVER
Fig. 2 Seal Location
1 - REAR COVER
2 - END COVER
3 - OUTER HALFSHAFT SEAL
4 - P.T.U. CASE
5 - P.T.U. OUTPUT SEAL
RSPOWER TRANSFER UNIT21-3
POWER TRANSFER UNIT (Continued)
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FLUID LEAK DIAGNOSIS
When diagnosing fluid leaks on the Power Transfer
Unit two weep holes are provided to diagnose certain
seal leaks. These holes are located on the bottom side
of the assembly (Fig. 5).
If fluid leak is detected from either weep hole, seal
replacement is necessary.Do not attempt to repair
the leak by sealing weep holes,they must be kept
clear of sealants for proper seal operation.
If fluid is leaking from weep hole A (Fig. 5) the
type of fluid leaking will determine which seal needs
to be replaced. If the fluid leaking is red in color(transmission fluid) this indicates that the Transmis-
sion differential carrier seal should be replaced. If
the fluid leaking is light brown (gear lube) this indi-
cates that the Power Transfer Unit input seal should
be replaced. For replacement of these seals refer to
Power Transfer Unit Service Procedures.
If fluid is leaking from weep hole B (Fig. 5) the
type of fluid leaking will determine which seal is
leaking. If the fluid leaking is red in color (transmis-
sion fluid) this indicates that the input shaft end seal
should be replaced. If the fluid leaking is light brown
(gear lube) this indicates that the half shaft inner
seal and P.T.U. input shaft cover seal should be
replaced. For replacement of these seals refer to
Power Transfer Unit Service Procedures.
Before condemning any seal or gasket be sure that
the rear rocker arm cover on the engine is not the
cause of the oil leak. Oil leaking from the rocker arm
cover is easily mistaken for a leaking Power Transfer
Unit.
Fig. 3 Seal Location
1 - INPUT SHAFT
2 - OUTPUT SHAFT
3 - REAR COVER
4 - P.T.U. CASE
5 - INPUT SHAFT SEAL
Fig. 4 Seal Location
1 - P.T.U. INPUT SHAFT COVER SEAL
2 - HALF SHAFT INNER SEAL
3 - INSIDE VIEW OF P.T.U. END COVER
Fig. 5 Weep Hole Locations
1 - ENGINE OIL PAN
2 - WEEP HOLE ªAº
3 - TRANSAXLE CASE
4 - P.T.U.
5 - WEEP HOLE ªBº
21 - 4 POWER TRANSFER UNITRS
POWER TRANSFER UNIT (Continued)
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(4) Add 1.15 liters (1.22 quarts) of MopartGear
and Axle Lubricant 80W-90 with suction gun (Fig. 9).
(5) Install inspection plug and torque to 20 N´m
(180 in. lbs.) torque.
(6) Lower vehicle.
REMOVAL
(1) Raise vehicle and remove front wheels.
CAUTION: A certain amount of oil will drain out of
the transaxle when the drive shaft is removed.
(2) Remove right front drive shaft. Install a plug
into the right driveshaft seal hole. (Refer to 3 - DIF-
FERENTIAL & DRIVELINE/HALF SHAFT -
REMOVAL)
(3) Mark propeller shaft front flange.
CAUTION: Do not let propeller shaft to hang freely.
Damage to the shaft will occur.
(4) Remove propeller shaft assembly (Fig. 10).
(Refer to 3 - DIFFERENTIAL & DRIVELINE/PRO-
PELLER SHAFT - REMOVAL)
(5) Remove cradle plate (Fig. 11).
(6) Remove the Power Transfer Unit mounting
bracket bolts at the rear of the unit (Fig. 12).
(7) Remove the right outboard support bracket and
bolts near the right axle shaft.
Fig. 11 Cradle Plate
1 - CRADLE PLATE
Fig. 12 Remove Rear P.T.U Bracket Bolts
1 - P.T.U. MOUNT BRACKET
2 - P.T.U.
Fig. 9 Adding Fluid to PTU
1 - SUCTION GUN
2 - INSPECTION HOLE
Fig. 10 Driveshaft Flange
1 - DRIVESHAFT FLANGE
21 - 6 POWER TRANSFER UNITRS
POWER TRANSFER UNIT (Continued)
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31TH AUTOMATIC TRANSAXLE
TABLE OF CONTENTS
page page
31TH AUTOMATIC TRANSAXLE
DESCRIPTION.........................22
OPERATION...........................24
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - PRELIMINARY
DIAGNOSIS..........................24
DIAGNOSIS AND TESTING - ROAD TEST . . . 31
DIAGNOSIS AND TESTING - HYDRAULIC
PRESSURE TESTS....................32
DIAGNOSIS AND TESTING - TORQUE
CONVERTER HOUSING FLUID LEAKAGE . . . 35
DIAGNOSIS AND TESTING - CLUTCH AND
SERVO AIR PRESSURE TESTS..........35
STANDARD PROCEDURE - ALUMINUM
THREAD REPAIR......................37
REMOVAL.............................37
DISASSEMBLY.........................40
ASSEMBLY............................51
INSTALLATION.........................61
SCHEMATICS AND DIAGRAMS
31TH TRANSAXLE HYDRAULIC
SCHEMATICS........................64
SPECIFICATIONS
31TH AUTOMATIC TRANSAXLE..........72
SPECIAL TOOLS
31TH AUTOMATIC TRANSAXLE..........75
ACCUMULATOR
DESCRIPTION.........................79
OPERATION...........................79
BANDS
DESCRIPTION
KICKDOWN (FRONT) BAND.............80
OPERATION
LOW/REVERSE (REAR) BAND...........80
ADJUSTMENTS
ADJUSTMENT - FRONT BAND...........80
ADJUSTMENTS - REAR BAND...........80
CLUTCH - FRONT
DESCRIPTION.........................82
OPERATION...........................82
DISASSEMBLY.........................82
ASSEMBLY............................84
CLUTCH - REAR
DESCRIPTION.........................86
OPERATION...........................86
DISASSEMBLY.........................87
ASSEMBLY............................89
FINAL DRIVE
DISASSEMBLY.........................91
ASSEMBLY............................94ADJUSTMENTS
ADJUSTMENT - DIFFERENTIAL BEARING . . 97
FLUID
STANDARD PROCEDURE
STANDARD PROCEDURE - FLUID LEVEL
AND CONDITION CHECK...............99
STANDARD PROCEDURE - FLUID AND
FILTER CHANGE......................99
GEAR SHIFT CABLE
REMOVAL............................101
INSTALLATION........................102
ADJUSTMENTS
GEARSHIFT CABLE ADJUSTMENT.......104
GOVERNOR
DESCRIPTION........................104
OPERATION..........................104
CLEANING...........................104
INSPECTION.........................104
OIL PUMP
DESCRIPTION........................105
OPERATION..........................105
STANDARD PROCEDURE - OIL PUMP
VOLUME CHECK.....................105
DISASSEMBLY........................106
CLEANING...........................106
INSPECTION.........................106
ASSEMBLY...........................107
PARK/NEUTRAL POSITION SWITCH
DIAGNOSIS AND TESTING - PARK/NEUTRAL
POSITION SWITCH...................107
REMOVAL............................107
INSTALLATION........................107
PLANETARY GEARTRAIN
DISASSEMBLY........................108
ASSEMBLY...........................109
SEAL - OIL PUMP
REMOVAL............................110
INSTALLATION........................110
SERVO - KICKDOWN
DESCRIPTION........................111
OPERATION..........................111
DISASSEMBLY........................111
CLEANING...........................112
INSPECTION..........................113
ASSEMBLY...........................113
SERVO - LOW/REVERSE
DESCRIPTION........................113
OPERATION..........................113
DISASSEMBLY........................114
CLEANING...........................114
RS31TH AUTOMATIC TRANSAXLE21-21
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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 - SHAFT
10 - GOVERNOR
11 - DIFFERENTIAL
RS31TH AUTOMATIC TRANSAXLE21-23
31TH AUTOMATIC TRANSAXLE (Continued)
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(5) Line pressure should read 52 to 58 psi with
throttle lever clockwise. Pressure should gradually
increase to 80 to 88 psi.as lever is moved counter-
clockwise.
(6) Low/reverse pressure should read the same as
line pressure, within 3 psi.
(7) This tests pump output, pressure regulation,
and condition of rear clutch and rear servo hydraulic
circuits.
TEST TWO (SELECTOR IN 2)
(1) Attach one gauge to line pressure port, and tee
another gauge into lower cooler line fitting. This will
allow lubrication pressure readings to be taken.
(2) Operate engine at 1000 rpm for test.
(3) Move selector lever on transaxle one detent for-
ward from full rearward position. This is selector 2
position.
Fig. 1 Test Port Locations
1 - ACCUMULATOR VENT 8 - TO COOLER
2 - MANUAL THROTTLE LEVER SHAFT 9 - KICKDOWN RELEASE (FRONT CLUTCH)
3 - MANUAL SHIFT LEVER SHAFT 10 - KICKDOWN APPLY
4 - LOW-REVERSE PRESSURE 11 - CONVERTER CLUTCH SOLENOID CONNECTOR
5 - GOVERNER PRESSURE (BELOW DIFFERENTIAL COVER ON
RIGHT SIDE)12 - FROM COOLER
6 - LINE PRESSURE 13 - KICKDOWN BAND ADJUSTING SCREW
7 - KICKDOWN APPLY AT ACCUMULATOR
Fig. 2 Governor Pressure Tap
1 - GOVERNOR PRESSURE PLUG
RS31TH AUTOMATIC TRANSAXLE21-33
31TH AUTOMATIC TRANSAXLE (Continued)
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(4) Read pressures on both gauges as throttle lever
on transaxle is moved from full clockwise position to
full counterclockwise position.
(5) Line pressure should read 52 to 58 psi with
throttle lever clockwise. Pressure should gradually
increase to 80 to 88 psi. as lever is moved counter-
clockwise.
(6) Lubrication pressure should be 10 to 25 psi
with lever clockwise and 10 to 35 psi with lever at
full counterclockwise.
(7) This tests pump output, pressure regulation,
and condition of rear clutch and lubrication hydraulic
circuits.
TEST THREE (SELECTOR IN D)
(1) Attach gauges to line and kickdown release
ports.
(2) Operate engine at 1600 rpm for test.
(3) Move selector lever on transaxle two detents
forward from full rearward position. This is selector
D position.
(4) Read pressures on both gauges as throttle lever
on transaxle is moved from full clockwise to the full
counterclockwise position.
(5) Line pressure should read 52 to 58 psi with
throttle lever clockwise. Pressure should gradually
increase to 80 to 88 psi. as lever is moved counter-
clockwise.
(6) Kickdown release is pressurized only in direct
drive and should be same as line pressure within 3
psi, up to kickdown point.
(7) This tests pump output, pressure regulation,
and condition of rear clutch, front clutch, and
hydraulic circuits.
TEST FOUR (SELECTOR IN REVERSE)
(1) Attach 300 psi gauge (C-3292SP) to low-reverse
port.
(2) Operate engine at 1600 rpm for test.
(3) Move selector lever on transaxle four detents
forward from full rearward position. This is selector
R position.
(4) Low/reverse pressure should read 180 to 220
psi with throttle lever clockwise. Pressure should
gradually increase to 260 to 300 psi. as lever is
moved counterclockwise.(5) This tests pump output, pressure regulation,
and condition of front clutch and rear servo hydraulic
circuits.
(6) Move selector lever on transaxle to D position
to check that low/reverse pressure drops to zero.
(7) This tests for leakage into rear servo, due to
case porosity, which can cause reverse band burn out.
TEST RESULT INDICATIONS
(1) If proper line pressure, minimum to maximum,
is found in any one test, the pump and pressure reg-
ulator are working properly.
(2) Low pressure in D, 1, and 2 but correct pres-
sure in R, indicates rear clutch circuit leakage.
(3) Low pressure in D and R, but correct pressure
in 1 indicates front clutch circuit leakage.
(4) Low pressure in R and 1, but correct pressure
in 2 indicates rear servo circuit leakage.
(5) Low line pressure in all positions indicates a
defective pump, a clogged filter, or a stuck pressure
regulator valve.
GOVERNOR PRESSURE
Test only if transaxle shifts at wrong vehicle
speeds when throttle cable is correctly adjusted.
(1) Connect a 100 psi gauge to governor pressure
port. It is located at lower right side of case, below
differential cover (Fig. 2).
(2) Operate transaxle in third gear to read pres-
sures. The governor pressure should respond
smoothly to changes in mph and should return to 0
to 3 psi when vehicle is stopped. High pressure
(above 3 psi) at standstill will prevent the transaxle
from downshifting.
THROTTLE PRESSURE
No gauge port is provided for throttle pressure.
Incorrect throttle pressure should be suspected if
part throttle upshift speeds are either delayed or
occur too early in relation to vehicle speed. Engine
runaway on shifts can also be an indicator of low
throttle pressure setting, or misadjusted throttle
cable.
In no case should throttle pressure be adjusted
until the transaxle throttle cable adjustment has
been verified to be correct.
21 - 34 31TH AUTOMATIC TRANSAXLERS
31TH AUTOMATIC TRANSAXLE (Continued)
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(13) Install rear clutch assembly (Fig. 69). Ensure
that all clutch discs are engaged to front planetary
gear splines or transaxle failure will result.
(14) Install #2 thrust washer (Fig. 69).
(15) Install front clutch assembly (Fig. 70). Ensure
that all clutch discs are engaged to rear clutch
retainer splines or transaxle failure will result.(16) Install kickdown band (Fig. 71). Do not install
strut or adjust at this time.
(17) Install oil pump gasket (Fig. 72).
Fig. 69 No. 2 Thrust Washer and Rear Clutch
1 - REAR CLUTCH ASSEMBLY
2 - #2 THRUST WASHER
Fig. 70 Front Clutch Assembly
1 - REAR CLUTCH ASSEMBLY
2 - FRONT CLUTCH ASSEMBLY
Fig. 71 Kickdown Band and Strut
1 - FRONT CLUTCH
2 - KICKDOWN BAND
3 - OIL RETURN AND FEED HOLE TO DIFFERENTIAL
4 - STRUT
Fig. 72 Oil Pump Gasket
1 - SPLIT IN GASKET (DIFFERENTIAL OIL FEED)
2 - PUMP GASKET
3 - PUMP GASKET DIFFERENTIAL OIL FEED CUTOUT
21 - 54 31TH AUTOMATIC TRANSAXLERS
31TH AUTOMATIC TRANSAXLE (Continued)
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