differential CHRYSLER CARAVAN 2002 Workshop Manual

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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DIFFERENTIAL CARRIER SEAL
REMOVAL
The Power Transfer Unit must be removed from
the vehicle to replace this seal.
(1) Remove P.T.U. from vehicle.
(2) Use a pry bar to remove seal from retainer
plate (Fig. 16). Be careful not to damage seal journal
when removing seal.
INSTALLATION
The Power Transfer Unit must be removed from
the vehicle to replace this seal.
(1) Using a large socket, carefully install new seal.
The spring side of the seal must face the transaxle
differential.
(2) Reinstall the P.T.U. into the vehicle.
(3) Check and fill fluids as required.
END COVER BALL BEARING
REMOVAL
The end cover ball bearing can be removed and
installed without removing the Power Transfer Unit
from the vehicle. When replacing the bearing the output
seal must be removed to gain access to the bearing.
(1) Raise vehicle on hoist.
(2) Remove right front half shaft from vehicle.
(3) Remove output seal with a hammer and chisel
(Fig. 17).
Fig. 17 Output Seal Removal
1 - HAMMER
2 - CHISEL
3 - SEAL
4 - POWER TRANSFER UNIT
MD998334 Seal Installer
MD998346 Bearing Puller
Fig. 16 Transaxle Differential Carrier Seal
1 - TRANSAXLE CASE
2 - DIFFERENTIAL CARRIER SEAL
3 - RETAINER PLATE
RSPOWER TRANSFER UNIT21-9
POWER TRANSFER UNIT (Continued)
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INSTALLATION
The power transfer unit half shaft inner seal is the
smaller of the two seals located on the inside of the
end cover.
(1) Clean and inspect seal area.
(2) Install seal with a 1 1/16 inch socket (Fig. 28).
The seal must be installed with the spring side of the
seal facing end cover ball bearing. The seal will bot-
tom against a machined shoulder in the cover.
(3) Clean sealing surfaces of the end cover and
P.T.U. case. Apply a bead of MopartGasket Maker,
Loctite Gasket Eliminator No. 518 or equivalent.
(4) Place end cover onto P.T.U. case and install
bolts. Tighten bolts to 28 N´m (250 in. lbs.) in the
sequence shown in (Fig. 29). Retighten first bolt after
all other bolts are tight.
(5) Reinstall P.T.U. assembly.
(6) Check and fill fluids as required.
INPUT SHAFT COVER SEAL
REMOVAL
The power transfer unit input shaft cover seal is
the larger of the two seals located on the inside of
the end cover. The differential bearing cup must be
removed to service this seal.
(1) Remove P.T.U. end cover bolts (Fig. 30).
Fig. 28 Seal Installation
1 - END COVER
2 - SOCKET
3 - HAMMER
Fig. 29 Bolt Tightening Sequence
Fig. 30 P.T.U. End Cover Bolts
1 - POWER TRANSFER UNIT
2 - FILL PLUG
3 - END COVER
4 - OUTPUT SHAFT
RSPOWER TRANSFER UNIT21-13
HALF SHAFT INNER SEAL (Continued)
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(2) Gently tap on end cover ears to separate cover
from case (Fig. 31).
(3) Use special tool No. 6514 and remove the dif-
ferential bearing race located in the end cover (Fig.
32). The race must be removed to gain access to the
seal.(4) Use special tool No. 7794-A to remove seal (Fig.
33).
INSTALLATION
The power transfer unit input shaft cover seal is
the larger of the two seals located on the inside of
the end cover. The differential bearing cup must be
removed to service this seal.
(1) Clean and inspect seal area.
(2) Use special tool No. MD998803 and install seal
(Fig. 34). When installing seal the spring side of the
seal must face toward the special tool.
Fig. 31 End Cover Removal
1 - END COVER EARS
2 - HAMMER
3 - POWER TRANSFER UNIT
Fig. 32 Bearing Race Removal
1 - END COVER
2 - SPECIAL TOOL
No. 6514
Fig. 33 Seal Removal
1 - END COVER
2 - SPECIAL TOOL 7794±A
3 - SLIDE HAMMER
4 - SOFT JAW VICE
Fig. 34 Seal Installation
1 - SPECIAL TOOL No. MD998803
2 - HAMMER
3 - END COVER
21 - 14 POWER TRANSFER UNITRS
INPUT SHAFT COVER SEAL (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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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
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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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ries the governor and parking sprag. An integral heli-
cal gear on the transfer shaft drives the differential
ring gear.
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
DIAGNOSIS AND TESTING - PRELIMINARY
DIAGNOSIS
Automatic transaxle malfunctions are usually
caused by the following general conditions:
²Improper fluid level/condition²Poor engine performance
²Improper engine or transaxle adjustments
²Transaxle hydraulic malfunctions
²Transaxle 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.
21 - 24 31TH AUTOMATIC TRANSAXLERS
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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