transmission CHRYSLER CARAVAN 2002 Service Manual

INSTALLATION
(1) Install transaxle assembly to engine using a
transmission jack and helper.
(2) Install and torque transaxle-to-engine bolts to
95 N´m (70 ft. lbs.).
(3) Using screw jack and wood block, raise engine/
transaxle assembly into position and install left
upper mount thru-bolt (Fig. 97). Torque bolt to 75
N´m (55 ft. lbs.).
(4) Install left wheel splash shield.
(5) Install torque converter-to-drive plate bolts and
torque to 88 N´m (65 ft. lbs.).
(6) Install rear mount bracket to transaxle (Fig.
98). Install bolts by hand but do not tighten at this
time.
(7) Align rear mount bracket to mount and install
thru-bolt. Do not tighten at this time.
(8) Connect vehicle speed sensor connector.
Fig. 97 Left Mount-to-Rail
1 - FRAME BRACKET
2 - FRAME RAIL - LEFT
3 - BOLT
4 - TRANSAXLE MOUNT
Fig. 98 Rear Mount Bracket
1 - BOLT - VERTICAL
2 - BRACKET - REAR MOUNT3 - BOLT - HORIZONTAL
RS31TH AUTOMATIC TRANSAXLE21-61
31TH AUTOMATIC TRANSAXLE (Continued)
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(13) Install halfshafts. (Refer to 3 - DIFFEREN-
TIAL & DRIVELINE/HALF SHAFT - INSTALLA-
TION)
(14) Lower vehicle.
(15) Torque rear mount bracket-to-transaxle verti-
cal bolts (Fig. 98) to 102 N´m (75 ft. lbs.).
(16) Connect back up lamp switch connector.
(17) Connect gearshift cable to manual valve and
left upper mount bracket (Fig. 102).
(18) Connect throttle valve cable to lever and
bracket (Fig. 103).
(19) Connect torque converter clutch connector.
(20) Install fluid level indicator/tube assembly
(Fig. 104).
(21) Raise vehicle on hoist.
(22) Torque rear mount bracket-to-transaxle case
horizontal bolt (Fig. 98) to 102 N´m (75 ft. lbs.).
(23) Torque rear mount thru-bolt to 54 N´m (40 ft.
lbs.).
(24) Lower vehicle.
(25) Connect battery negative cable.
(26) Fill transaxle with ATF+4 transmission fluid.
(Refer to 21 - TRANSMISSION/TRANSAXLE/AUTO-
MATIC - 31TH/FLUID - STANDARD PROCEDURE)
Fig. 102 Gearshift Cable at Transaxle
1 - MANUAL VALVE LEVER
2 - GEAR SHIFT CABLE
3 - UPPER MOUNT BRACKET
Fig. 103 Kickdown Cable at TransaxleÐTypical
1 - LEVER
2 - BRACKET
3 - THROTTLE VALVE CABLE
Fig. 104 Fluid Level Indicator Assembly
1 - INDICATOR ASSEMBLY
2 - BOLT
3 - KICKDOWN CABLE BRACKET
4 - SEAL
RS31TH AUTOMATIC TRANSAXLE21-63
31TH AUTOMATIC TRANSAXLE (Continued)
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ACCUMULATOR
DESCRIPTION
The accumulator (Fig. 105) is a hydraulic device
that has the sole purpose of cushioning the applica-
tion of a band or clutch. The accumulator consists of
a dual-land piston and a spring located in a bore in
the transmission case.
OPERATION
Line pressure is directed between the lands of the
piston (Fig. 106), bottoming it against the accumula-
tor plate. The accumulator stays in this position after
the transmission is placed into a Drive position.
When the 1-2 upshift occurs (Fig. 107), line pressure
is directed to the large end of the piston and then to
the kickdown servo. As the line pressure reaches the
accumulator, the combination of spring pressure and
line pressure forces the piston away from the accu-
mulator plate. This causes a balanced pressure situ-
ation, which results in a cushioned band application.
After the kickdown servo has become immovable, line
pressure will finish pushing the accumulator up into
its bore. When the large end of the accumulator pis-
ton is seated in its bore, the band or clutch is fully
applied.
NOTE: The accumulator is shown in the inverted
position for illustrative purposes.
Fig. 105 Accumulator
1 - ACCUMULATOR PISTON
2 - PISTON SPRINGFig. 106 Accumulator in Neutral and Drive Positions
Fig. 107 Accumulator in Second Gear Position
1 - BOTTOM IN BORE
2 - SHUTTLE VALVE
RS31TH AUTOMATIC TRANSAXLE21-79
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BANDS
DESCRIPTION
KICKDOWN (FRONT) BAND
DESCRIPTION
The kickdown, or ªfrontº, band (Fig. 108) holds the
common sun gear of the planetary gear sets. The
front (kickdown) band is made of steel, and faced on
its inner circumference with a friction-type lining.
One end of the band is anchored to the transmission
case, and the other is acted on with a pushing force
by a servo piston. The front band is a single-wrap
design (the band does not completely encompass/
wrap the drum that it holds).
OPERATION
The kickdown band holds the common sun gear of
the planetary gear sets by applying and holding the
front clutch retainer, which is splined to the sun gear
driving shell, and in turn splined directly to the sun
gear. The application of the band by the servo is typ-
ically done by an apply lever and link bar.
OPERATION
LOW/REVERSE (REAR) BAND
DESCRIPTION
The low/reverse band, or ªrearº, band (Fig. 109) is
similar in appearance and operation to the front
band. The rear band is also a single-wrap design (the band does not completely encompass/wrap the
drum that it holds).
OPERATION
The rear band holds the rear planet carrier sta-
tionary by being mounted around and applied to the
low/reverse drum.
ADJUSTMENTS
ADJUSTMENT - FRONT BAND
The front (kickdown) band adjusting screw is
located on the left side of the transmission case
above the manual valve and throttle valve levers.
(1) Disconnect battery negative cable.
(2) Remove air cleaner assembly.
(3) Loosen band adjusting screw locknut (Fig. 110).
Then back locknut off 3-5 turns. Be sure adjusting
screw turns freely in case. Apply lubricant to screw
threads if necessary.
(4) Tighten band adjusting screw to 8 N´m (72 in.
lbs.).
(5) Back off front band adjusting screw 2
1¤4turns.
(6) Hold adjuster screw in position and tighten
locknut to 47 N´m (35 ft. lbs.) torque.
(7) Install air cleaner assembly.
(8) Connect battery negative cable.
ADJUSTMENTS - REAR BAND
The transmission oil pan must be removed for
access to the rear (low/reverse) band adjusting screw.
(1) Raise vehicle.
Fig. 108 Front BandÐTypical
1 - FRONT BAND
2 - TRANSMISSION HOUSING
Fig. 109 Rear Band
1 - PLANETARY GEARTRAIN
2 - REAR BAND
3 - LEVER
4 - SERVO
5 - ADJUSTER
21 - 80 31TH AUTOMATIC TRANSAXLERS
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(2) Remove transaxle oil pan and drain fluid (Fig.
111) (Fig. 112).
(3) Loosen band adjusting screw locknut 5-6 turns.
Be sure adjusting screw turns freely in lever.
(4) Tighten adjusting screw to 5 N´m (41 in. lbs.)
(Fig. 113).
(5) Back off adjusting screw 3
1¤2turns.
(6) Hold adjusting screw in place and tighten lock-
nut to 14 N´m (125 ft. lbs.) torque.
(7) Install a bead of MopartSilicone Rubber Adhe-
sive Sealant to the oil pan and install to case imme-
diately.
(8) Install oil pan-to-case bolts and torque to 19
N´m (165 in. lbs.).(9) Lower vehicle and refill transmission with
MopartATF Plus 4, Type 9602, fluid.
Fig. 110 Front (Kickdown) Band Adjustment
Location
1 - KICKDOWN BAND ADJUSTING SCREW
Fig. 111 Transaxle Oil Pan Bolts
1 - TRANSAXLE OIL PAN
2 - OIL PAN BOLTS
Fig. 112 Transaxle Oil Pan
1 - TRANSAXLE OIL PAN
2 - OIL FILTER
Fig. 113 Adjust Low/Reverse Band
1 - LOW-REVERSE BAND LEVER
2 - ADJUSTING SCREW
3 - STRUT
4 - LOW-REVERSE BAND
5 - LOCK NUT
6 - LEVER (SHORT)
RS31TH AUTOMATIC TRANSAXLE21-81
BANDS (Continued)
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CLUTCH - FRONT
DESCRIPTION
The front clutch assembly (Fig. 119) is composed of
the front clutch retainer, pressure plate, clutch
plates, driving discs, piston, piston return spring,
return spring retainer, and snap-rings. The front
clutch is the forward-most component in the trans-
mission geartrain and is directly behind the oil
pump. It is considered a driving component.
NOTE: The number of discs and plates may vary
with each engine and vehicle combination.
OPERATION
To apply the clutch, pressure is applied between
the clutch retainer and piston. The fluid pressure is
provided by the oil pump, transferred through the
control valves and passageways, and enters the
clutch through the hub of the reaction shaft support.
With pressure applied between the clutch retainer
and piston, the piston moves away from the clutch
retainer and compresses the clutch pack. This action
applies the clutch pack, allowing torque to flow
through the input shaft into the driving discs, and
into the clutch plates and pressure plate that are
lugged to the clutch retainer. The waved snap-ring is
used to cushion the application of the clutch pack. In
some transmissions, the snap-ring is selective and
used to adjust clutch pack clearance.
When pressure is released from the piston, the
spring returns the piston to its fully released position
and disengages the clutch. The release spring also
helps to cushion the application of the clutch assem-
bly. When the clutch is in the process of being
released by the release spring, fluid flows through a
vent and one-way ball-check-valve located in the
clutch retainer. The check-valve is needed to elimi-
nate the possibility of plate drag caused by centrifu-
gal force acting on the residual fluid trapped in the
clutch piston retainer.
DISASSEMBLY
(1) Remove front clutch waved snap ring using a
suitable screwdriver (Fig. 114).
(2) Remove waved snap ring and reaction plate
(Fig. 115).
Fig. 114 Front Clutch Waved Snap Ring
1 - WAVED SNAP RING
2 - SCREWDRIVER
3 - FRONT CLUTCH ASSEMBLY
Fig. 115 Thick Steel Plate and Waved Snap Ring
1 - WAVED SNAP RING
2 - THICK STEEL PLATE
3 - FRONT CLUTCH RETAINER
21 - 82 31TH AUTOMATIC TRANSAXLERS
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(5) Using feeler gauge, measure front clutch clear-
ance (Fig. 125).Front clutch clearance should be
within 1.27-2.79 mm (0.050-0.110 in.) and is not
adjustable.
CLUTCH - REAR
DESCRIPTION
The rear clutch assembly (Fig. 132) is composed of
the input shaft, rear clutch retainer, pressure plate,
clutch plates, driving discs, piston, Belleville spring,
and snap-rings. The Belleville spring acts as a lever
to multiply the force applied on to it by the apply pis-
ton. The increased apply force on the rear clutch
pack, in comparison to the front clutch pack, is
needed to hold against the greater torque load
imposed onto the rear pack. The rear clutch is
directly behind the front clutch and is considered a
driving component.
NOTE: The number of discs and plates may vary
with each engine and vehicle combination.
OPERATION
To apply the clutch, pressure is applied between
the clutch retainer and piston. The fluid pressure is
provided by the oil pump, transferred through the
control valves and passageways, and enters the
clutch through the hub of the reaction shaft support.
With pressure applied between the clutch retainer
and piston, the piston moves away from the clutch
retainer and compresses the clutch pack. This action
applies the clutch pack, allowing torque to flow
through the input shaft into the driving discs, and
into the clutch plates and pressure plate that are
lugged to the clutch retainer. The waved snap-ring is
used to cushion the application of the clutch pack. In
some transmissions, the snap-ring is selective and
used to adjust clutch pack clearance.
When pressure is released from the piston, the
spring returns the piston to its fully released position
and disengages the clutch. The release spring also
helps to cushion the application of the clutch assem-
bly. When the clutch is in the process of being
released by the release spring, fluid flows through a
vent and one-way ball-check-valve located in the
clutch retainer. The check-valve is needed to elimi-
nate the possibility of plate drag caused by centrifu-
gal force acting on the residual fluid trapped in the
clutch piston retainer.
Fig. 124 Front Clutch Waved Snap Ring
1 - WAVED SNAP RING
2 - SCREWDRIVER
3 - FRONT CLUTCH ASSEMBLY
Fig. 125 Measuring Front Clutch Plate Clearance
1 - FEELER GAUGE
2 - FRONT CLUTCH ASSEMBLY
21 - 86 31TH AUTOMATIC TRANSAXLERS
CLUTCH - FRONT (Continued)
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(3) Install rear clutch pack (Fig. 137).
(4) Install snap ring using a suitable screwdriver
(Fig. 138).
(5) Using feeler gauges, measure rear clutch clear-
ance (Fig. 139).Rear clutch clearance should be
within 0.71-1.10 mm (0.028-0.043 in.).
FINAL DRIVE
DISASSEMBLY
NOTE: The differential is serviced as an assembly.
Service is limited to bearing cups and cones. Any
other failure must be repaired by differential assem-
bly and transfer shaft replacement.
(1) Remove transfer shaft.
(2) Measure differential bearing turning torque.
(Refer to 21 - TRANSMISSION/TRANSAXLE/AUTO-
MATIC - 31TH/BEARINGS - ADJUSTMENTS)
(3) Remove adapter plate seal.
(4) Remove differential cover-to-transaxle case
bolts (Fig. 140).
Fig. 137 Rear Clutch (4-Disc Shown)
1 - REAR CLUTCH RETAINER
2 - CLUTCH PLATES
3 - THICK STEEL PLATE
4 - SNAP RING (SELECTIVE)
5 - DRIVING DISCS
6 - PRESSURE PLATE
Fig. 138 Rear Clutch Outer Snap Ring
1 - SCREWDRIVER
2 - SNAP RING
3 - REAR CLUTCH ASSEMBLY
Fig. 139 Measuring Rear Clutch Plate Clearance
1 - REAR CLUTCH ASSEMBLY
2 - FEELER GAUGE
3 - SELECTIVE SNAP RING
Fig. 140 Differential Cover Bolts
1 - DIFFERENTIAL COVER
2 - DIFFERENTIAL COVER BOLT
RS31TH AUTOMATIC TRANSAXLE21-91
CLUTCH - REAR (Continued)
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(11) Install adapter plate axle seal using Tool
L-4520 (inverted), and driver handle C-4171.
(12) Check differential turning torque. (Refer to 21
- TRANSMISSION/TRANSAXLE/AUTOMATIC -
31TH/BEARINGS - ADJUSTMENTS)
(13) Apply an 1/8º bead of MopartSilicone Rubber
Adhesive Sealant to the differential cover (Fig. 161).
(14) Install differential cover-to-transaxle case
bolts and torque to 19 N´m (165 in. lbs.) torque (Fig.
162).
(15) Install transfer shaft and related components.ADJUSTMENTS
ADJUSTMENT - DIFFERENTIAL BEARING
NOTE: Transfer shaft MUST be removed from trans-
axle to obtain an accurate differential turning torque
measurement.
Differential turning torque should be measured
and adjusted during any transaxle or differential
teardown/assembly, or if any of the following parts
are replaced:
²Transaxle case
²Differential carrier
²Differential bearing retainer
²Extension housing
²Differential bearing cups and cones
(1) Position the transaxle assembly vertically on
the support stand, differential bearing retainer side
up.
(2) Install Tool L-4436A into the differential and
onto the pinion mate shaft (Fig. 163).
(3) Rotate the differential at least one full revolu-
tion to ensure the tapered roller bearings are fully
seated.
Fig. 161 Install Differential Cover
1 - GOVERNOR PRESSURE PLUG
2 - DIFFERENTIAL COVER
3 - 1/8 INCH BEAD OF R T V SEALANT
4 - DIFFERENTIAL ASSEMBLY
Fig. 162 Differential Cover Bolts
1 - DIFFERENTIAL COVER
2 - DIFFERENTIAL COVER BOLT
Fig. 163 Tool L-4436 and Torque Wrench
1 - SPECIAL TOOL L-4436±A
2 - TORQUE WRENCH
3 - DIFFERENTIAL BEARING RETAINER
RS31TH AUTOMATIC TRANSAXLE21-97
FINAL DRIVE (Continued)
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FLUID
STANDARD PROCEDURE
STANDARD PROCEDURE - FLUID LEVEL AND
CONDITION CHECK
NOTE: The transmission and differential sump have
a common oil sump with a communicating opening
between the two.
FLUID LEVEL CHECK
The torque converter fills in both the P Park and N
Neutral positions. Place the selector lever in P Park
to be sure that the fluid level check is accurate.The
engine should be running at idle speed for at
least one minute, with the vehicle on level
ground. This will assure complete oil level sta-
bilization between differential and transmis-
sion.The fluid should be at normal operating
temperature (approximately 82 C. or 180 F.). The
fluid level is correct if it is in the HOT region (cross-
hatched area) on the fluid level indicator (Fig. 165).
Low fluid level can cause a variety of conditions
because it allows the pump to take in air along with
the fluid. As in any hydraulic system, air bubbles
make the fluid spongy, therefore, pressures will be
low and build up slowly.
Improper filling can also raise the fluid level too
high. When the transaxle has too much fluid, the
gears churn up foam and cause the same conditions
which occur with a low fluid level.
In either case, the air bubbles can cause overheat-
ing, fluid oxidation, and varnishing. This can inter-
fere with normal valve, clutch, and servo operation.
Foaming can also result in fluid escaping from thetransaxle dipstick where it may be mistaken for a
leak.
FLUID CONDITION
Along with fluid level, it is important to check the
condition of the fluid. MopartATF+4 (Automatic
Transmission Fluid-Type 9602) when new is red in
color. The ATF is dyed red so it can be identified from
other fluids used in the vehicle such as engine oil or
antifreeze. The red color is not permanent and is not
an indicator of fluid condition. As the vehicle is
driven, the ATF will begin to look darker in color and
may eventually become brown.This is normal.
ATF+4 also has a unique odor that may change with
age. Consequently,odor and color cannot be used
to indicate the fluid condition, or the need for a
fluid change.
After the fluid has been checked, seat the dipstick
fully to seal out water and dirt.
STANDARD PROCEDURE - FLUID AND FILTER
CHANGE
NOTE: For the recommended maintenance (fluid/fil-
ter change) intervals for this transaxle, (Refer to
LUBRICATION & MAINTENANCE/MAINTENANCE
SCHEDULES - DESCRIPTION)
NOTE: Only fluids of the type labeled MoparTATF+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. Place a drain con-
tainer with a large opening, 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) Remove oil filter-to-valve body screws (Fig.
166).
(4) Remove oil filter and gasket (Fig. 167).
(5) Install a new filter and gasket (Fig. 167).
(6) Clean the oil pan and magnet. Reinstall pan
using new MopartSilicone Rubber Adhesive Sealant.
Torque oil pan bolts to 19 N´m (165 in. lbs.).
(7) Pour four quarts of MopartATF+4 (Automatic
Transmission Fluid-Type 9602) through the dipstick
opening.
Fig. 165 Fluid Level Indicator Markings
1 - TRANSAXLE DIPSTICK
RS31TH AUTOMATIC TRANSAXLE21-99
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