clutch CHRYSLER CARAVAN 2002 Service Manual
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Page 1829 of 2399

(41) Install the overdrive shaft assembly (Fig.
290).
(42) Reinstall overdrive and reverse clutch as
shown.Rechecking these clutch clearances is
not necessary.
OIL PUMP
DESCRIPTION
The oil pump is located in the pump housing inside
the bell housing of the transaxle case (Fig. 291). The
oil pump consists of an inner and outer gear, a hous-
ing, and a cover that also serves as the reaction shaft
support.
OPERATION
As the torque converter rotates, the converter hub
rotates the inner and outer gears. As the gears
rotate, the clearance between the gear teeth
increases in the crescent area, and creates a suction
at the inlet side of the pump. This suction draws
fluid through the pump inlet from the oil pan. As the
clearance between the gear teeth in the crescent area
decreases, it forces pressurized fluid into the pump
outlet and to the valve body.
STANDARD PROCEDURE - OIL PUMP VOLUME
CHECK
Measuring oil pump output volume will determine
if sufficient flow to the transmission oil cooler exists,
and whether or not an internal transmission failure
is present.
Verify that transmission fluid is at the proper
level. If adding fluid is necessary, fill to the properlevel with MopartATF+4 (Automatic Transmission
Fluid±Type 9602). The following procedure is to
check oil pump output volume:
(1) Using hose cutters or a suitable blade, cut the
ªto coolerº (Fig. 292) line off flush with the cooler
inlet fitting and place a collection container under
the open line.
Fig. 290 Install Overdrive Shaft Assembly
1 - OVERDRIVE SHAFT ASSEMBLY
2 - #3 THRUST PLATE
3 - #3 THRUST WASHER
Fig. 291 Oil Pump Assembly
1 - PUMP HOUSING
2 - OUTER PUMP GEAR
3 - INNER PUMP GEAR
4 - REACTION SHAFT SUPPORT
5 - SEAL RINGS (4)
6 - REACTION SHAFT
7 - CRESCENT
Fig. 292 Transaxle Oil Cooler Fittings
1 - FROM COOLER
2 - TO COOLER
21 - 272 41TE AUTOMATIC TRANSAXLERS
INPUT CLUTCH ASSEMBLY (Continued)
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(8) Position an appropriate piece of Plastigage
across both pump gears.
(9) Align the Plastigage to a flat area on the reac-
tion shaft support housing.
(10) Install the reaction shaft to the pump hous-
ing. Tighten the bolts to 27 N´m (20 ft. lbs.).
(11) Remove bolts and carefully separate the hous-
ings. Measure the Plastigage following the instruc-
tions supplied.
(12) Clearance between outer gear side and the
reaction shaft support should be 0.020-0.046 mm
(0.0008-0.0018 in.). Clearance between inner gear
side and the reaction shaft support should be 0.020-
0.046 mm (0.0008-0.0018 in.).
ASSEMBLY
(1) Assemble oil pump as shown in (Fig. 296)
(2) Install and torque reaction shaft support-to-oil
pump housing bolts to 28 N´m (20 ft. lbs.) torque.
PLANETARY GEARTRAIN
DESCRIPTION
The planetary geartrain is located between the
input clutch assembly and the rear of the transaxle
case. The planetary geartrain consists of two sun
gears, two planetary carriers, two annulus (ring)
gears, and one output shaft (Fig. 297).
OPERATION
The planetary geartrain utilizes two planetary gear
sets that connect the transmission input shaft to the
output shaft. Input and holding clutches drive or lock
different planetary members to change output ratio
or direction.
Fig. 296 Oil Pump Assembly
1 - PUMP HOUSING
2 - OUTER PUMP GEAR
3 - INNER PUMP GEAR
4 - REACTION SHAFT SUPPORT
5 - SEAL RINGS (4)
6 - REACTION SHAFT
7 - CRESCENT
Fig. 297 Planetary Geartrain
1 - FRONT SUN GEAR ASSEMBLY
2 - #6 THRUST BEARING
3 - #7 THRUST BEARING
4 - REAR CARRIER/FRONT ANNULUS ASSEMBLY
5 - REAR SUN GEAR
6 - FRONT CARRIER/REAR ANNULUS ASSEMBLY
21 - 274 41TE AUTOMATIC TRANSAXLERS
OIL PUMP (Continued)
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(3) Install steering column lower shroud.
(4) Install knee bolster (Fig. 311).
(5) Install instrument panel lower silencer (Fig.
312).
(6) Connect battery negative cable.
(7) Verify proper shift interlock system operation.
(Refer to 21 - TRANSMISSION/TRANSAXLE/AUTO-
MATIC - 31TH/SHIFT INTERLOCK SOLENOID -
OPERATION)SOLENOID/PRESSURE
SWITCH ASSY
DESCRIPTION
The Solenoid/Pressure Switch Assembly (Fig. 313)
is external to the transaxle and mounted to the
transaxle case. The assembly consists of four sole-
noids that control hydraulic pressure to the LR/CC,
2/4, OD, and UD friction elements. The reverse
clutch is controlled by line pressure from the manual
valve in the valve body. The solenoids are contained
within the Solenoid/Pressure Switch Assembly, and
can only be serviced by replacing the assembly.
The solenoid assembly also contains pressure
switches that monitor and send hydraulic circuit
information to the TCM. Likewise, the pressure
switches can only be service by replacing the assem-
bly.
Fig. 311 Knee Bolster
1 - KNEE BOLSTER
Fig. 312 Instrument Panel Lower Silencer
1 - INSTRUMENT PANEL LOWER SILENCERFig. 313 Solenoid/Pressure Switch Assembly
1 - SOLENOID AND PRESSURE SWITCH ASSEMBLY
RS41TE AUTOMATIC TRANSAXLE21 - 279
SHIFT INTERLOCK SOLENOID (Continued)
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OPERATION
SOLENOIDS
The solenoids receive electrical power from the
Transmission Control Relay through a single wire.
The TCM energizes or operates the solenoids individ-
ually by grounding the return wire of the solenoid
needed. When a solenoid is energized, the solenoid
valve shifts, and a fluid passage is opened or closed
(vented or applied), depending on its default operat-
ing state. The result is an apply or release of a fric-
tional element.
The 2/4 and UD solenoids are normally applied,
which by design allow fluid to pass through in their
relaxed or ªoffº state. This allows transaxle limp-in
(P,R,N,2) in the event of an electrical failure.
The continuity of the solenoids and circuits are
periodically tested. Each solenoid is turned on or off
depending on its current state. An inductive spike
should be detected by the TCM during this test. It no
spike is detected, the circuit is tested again to verify
the failure. In addition to the periodic testing, the
solenoid circuits are tested if a speed ratio or pres-
sure switch error occurs.
PRESSURE SWITCHES
The TCM relies on three pressure switches to mon-
itor fluid pressure in the L/R, 2/4, and OD hydraulic
circuits. The primary purpose of these switches is to
help the TCM detect when clutch circuit hydraulic
failures occur. The range for the pressure switch clos-
ing and opening points is 11-23 psi. Typically the
switch opening point will be approximately one psi
lower than the closing point. For example, a switch
may close at 18 psi and open at 17 psi. The switches
are continuously monitored by the TCM for the cor-
rect states (open or closed) in each gear as shown in
the following chart:
PRESSURE SWITCH STATES
GEAR L/R 2/4 OD
ROPOPOP
P/N CL OP OP
1st CL OP OP
2nd OP CL OP
DOPOPCL
OD OP CL CL
OP = OPEN
CL = CLOSED
A Diagnostic Trouble Code (DTC) will set if the
TCM senses any switch open or closed at the wrong
time in a given gear.The TCM also tests the 2/4 and OD pressure
switches when they are normally off (OD and 2/4 are
tested in 1st gear, OD in 2nd gear, and 2/4 in 3rd
gear). The test simply verifies that they are opera-
tional, by looking for a closed state when the corre-
sponding element is applied. Immediately after a
shift into 1st, 2nd, or 3rd gear with the engine speed
above 1000 rpm, the TCM momentarily turns on ele-
ment pressure to the 2/4 and/or OD clutch circuits to
identify that the appropriate switch has closed. If it
doesn't close, it is tested again. If the switch fails to
close the second time, the appropriate Diagnostic
Trouble Code (DTC) will set.
REMOVAL
NOTE: If solenoid/pressure switch assembly is
being replaced, it is necessary to perform the TCM
Quick Learn Procedure. (Refer to 8 - ELECTRICAL/
ELECTRONIC CONTROL MODULES/TRANSMISSION
CONTROL MODULE - STANDARD PROCEDURE)
(1) Disconnect battery negative cable.
(2) Remove air cleaner assembly.
(3) Disconnect solenoid/pressure switch assembly
connector.
(4) Disconnect input speed sensor connector.
(5) Remove input speed sensor (Fig. 314).
Fig. 314 Input Speed Sensor
1 - INPUT SPEED SENSOR
21 - 280 41TE AUTOMATIC TRANSAXLERS
SOLENOID/PRESSURE SWITCH ASSY (Continued)
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OPERATION
The Input Speed Sensor provides information on
how fast the input shaft is rotating. As the teeth of
the input clutch hub pass by the sensor coil (Fig.
319), an AC voltage is generated and sent to the
TCM. The TCM interprets this information as input
shaft rpm.The TCM compares the input speed signal with
output speed signal to determine the following:
²Transmission gear ratio
²Speed ratio error detection
²CVI calculation
The TCM also compares the input speed signal and
the engine speed signal to determine the following:
²Torque converter clutch slippage
²Torque converter element speed ratio
REMOVAL
(1) Disconnect battery negative cable.
(2) If necessary, disconnect and cap off transmis-
sion oil cooler lines.
(3) Disconnect input speed sensor connector.
(4) Unscrew and remove input speed sensor (Fig.
320).
(5) Inspect speed sensor o-ring (Fig. 321) and
replace if necessary.
Fig. 318 O-Ring Location
1 - INPUT SPEED SENSOR
2 - O-RING
Fig. 319 Sensor Relation to Input Clutch Hub
1 - INPUT SPEED SENSOR
2 - TRANSAXLE CASE
3 - INPUT CLUTCH HUB
Fig. 320 Input (Turbine) Speed Sensor
1 - INPUT SPEED SENSOR
21 - 282 41TE AUTOMATIC TRANSAXLERS
SPEED SENSOR - INPUT (Continued)
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TORQUE CONVERTER
DESCRIPTION
The torque converter (Fig. 327) is a hydraulic
device that couples the engine crankshaft to the
transmission. The torque converter consists of an
outer shell with an internal turbine, a stator, an
overrunning clutch, an impeller and an electronically
applied converter clutch. The converter clutch pro-
vides reduced engine speed and greater fuel economy
when engaged. Clutch engagement also provides
reduced transmission fluid temperatures. The con-
verter clutch engages in third gear. The torque con-
verter hub drives the transmission oil (fluid) pump.
The torque converter is a sealed, welded unit that
is not repairable and is serviced as an assembly.
CAUTION: The torque converter must be replaced if
a transmission failure resulted in large amounts of
metal or fiber contamination in the fluid. If the fluid
is contaminated, flush the fluid cooler and lines.
Fig. 327 Torque Converter Assembly
1 - TURBINE
2 - IMPELLER
3 - HUB
4-STATOR
5 - CONVERTER CLUTCH DISC
6 - DRIVE PLATE
RS41TE AUTOMATIC TRANSAXLE21 - 285
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STATOR
The stator assembly (Fig. 330) is mounted on a sta-
tionary shaft which is an integral part of the oil
pump. The stator is located between the impeller and
turbine within the torque converter case (Fig. 331).
The stator contains an over-running clutch, which
allows the stator to rotate only in a clockwise direc-
tion. When the stator is locked against the over-run-
ning clutch, the torque multiplication feature of the
torque converter is operational.
TORQUE CONVERTER CLUTCH (TCC)
The TCC (Fig. 332) was installed to improve the
efficiency of the torque converter that is lost to the
slippage of the fluid coupling. Although the fluid cou-
pling provides smooth, shock±free power transfer, it
is natural for all fluid couplings to slip. If the impel-
ler and turbine were mechanically locked together, a
zero slippage condition could be obtained. A hydraulic
piston was added to the turbine, and a friction mate-
rial was added to the inside of the front cover to pro-
vide this mechanical lock-up.
Fig. 330 Stator Components
1 - CAM (OUTER RACE)
2 - ROLLER
3 - SPRING
4 - INNER RACE
Fig. 331 Stator Location
1-STATOR
2 - IMPELLER
3 - FLUID FLOW
4 - TURBINE
Fig. 332 Torque Converter Clutch (TCC)
1 - IMPELLER FRONT COVER
2 - THRUST WASHER ASSEMBLY
3 - IMPELLER
4-STATOR
5 - TURBINE
6 - PISTON
7 - FRICTION DISC
21 - 288 41TE AUTOMATIC TRANSAXLERS
TORQUE CONVERTER (Continued)
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OPERATION
The converter impeller (Fig. 333) (driving member),
which is integral to the converter housing and bolted
to the engine drive plate, rotates at engine speed.
The converter turbine (driven member), which reacts
from fluid pressure generated by the impeller, rotates
and turns the transmission input shaft.
TURBINE
As the fluid that was put into motion by the impel-
ler blades strikes the blades of the turbine, some of
the energy and rotational force is transferred into the
turbine and the input shaft. This causes both of them
(turbine and input shaft) to rotate in a clockwise
direction following the impeller. As the fluid is leav-
ing the trailing edges of the turbine's blades it con-
tinues in a ªhinderingº direction back toward the
impeller. If the fluid is not redirected before it strikes
the impeller, it will strike the impeller in such a
direction that it would tend to slow it down.
STATOR
Torque multiplication is achieved by locking the
stator's over-running clutch to its shaft (Fig. 334).
Under stall conditions (the turbine is stationary), the
oil leaving the turbine blades strikes the face of the
stator blades and tries to rotate them in a counter-
clockwise direction. When this happens the over±run-
ning clutch of the stator locks and holds the statorfrom rotating. With the stator locked, the oil strikes
the stator blades and is redirected into a ªhelpingº
direction before it enters the impeller. This circula-
tion of oil from impeller to turbine, turbine to stator,
and stator to impeller, can produce a maximum
torque multiplication of about 2.4:1. As the turbine
begins to match the speed of the impeller, the fluid
that was hitting the stator in such as way as to
cause it to lock±up is no longer doing so. In this con-
dition of operation, the stator begins to free wheel
and the converter acts as a fluid coupling.
TORQUE CONVERTER CLUTCH (TCC)
In a standard torque converter, the impeller and
turbine are rotating at about the same speed and the
stator is freewheeling, providing no torque multipli-
cation. By applying the turbine's piston to the front
cover's friction material, a total converter engage-
ment can be obtained. The result of this engagement
is a direct 1:1 mechanical link between the engine
and the transmission.
The engagement and disengagement of the TCC
are automatic and controlled by the Powertrain Con-
trol Module (PCM). The engagement cannot be acti-
vated in the lower gears because it eliminates the
torque multiplication effect of the torque converter
necessary for acceleration. Inputs that determine
clutch engagement are: coolant temperature, vehicle
speed and throttle position. The torque converter
Fig. 333 Torque Converter Fluid Operation
1 - APPLY PRESSURE 3 - RELEASE PRESSURE
2 - THE PISTON MOVES SLIGHTLY FORWARD 4 - THE PISTON MOVES SLIGHTLY REARWARD
RS41TE AUTOMATIC TRANSAXLE21 - 289
TORQUE CONVERTER (Continued)
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clutch is engaged by the clutch solenoid on the valve
body. The clutch will engage at approximately 56
km/h (35 mph) with light throttle, after the shift to
third gear.
REMOVAL
(1) Remove transmission and torque converter
from vehicle. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 41TE - REMOVAL)
(2) Place a suitable drain pan under the converter
housing end of the transmission.
CAUTION: Verify that transmission is secure on the
lifting device or work surface, the center of gravity
of the transmission will shift when the torque con-
verter is removed creating an unstable condition.
The torque converter is a heavy unit. Use caution
when separating the torque converter from the
transmission.
(3) Pull the torque converter forward until the cen-
ter hub clears the oil pump seal.
(4) Separate the torque converter from the trans-
mission.
INSTALLATION
Check converter hub and drive notches for sharp
edges, burrs, scratches, or nicks. Polish the hub and
notches with 320/400 grit paper or crocus cloth if nec-
essary. The hub must be smooth to avoid damaging
the pump seal at installation.
(1) Lubricate converter hub and oil pump seal lip
with transmission fluid.(2) Place torque converter in position on transmis-
sion.
CAUTION: Do not damage oil pump seal or bushing
while inserting torque converter into the front of the
transmission.
(3) Align torque converter to oil pump seal open-
ing.
(4) Insert torque converter hub into oil pump.
(5) While pushing torque converter inward, rotate
converter until converter is fully seated in the oil
pump gears.
(6) Check converter seating with a scale and
straightedge (Fig. 335). Surface of converter lugs
should be 1/2 in. to rear of straightedge when con-
verter is fully seated.
(7) If necessary, temporarily secure converter with
C-clamp attached to the converter housing.
(8) Install the transmission in the vehicle. (Refer
to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC
- 41TE - INSTALLATION)
(9) Fill the transmission with the recommended
fluid. (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 41TE/FLUID - STANDARD PROCE-
DURE)
Fig. 334 Stator Operation
1 - DIRECTION STATOR WILL FREE WHEEL DUE TO OIL
PUSHING ON BACKSIDE OF VANES
2 - FRONT OF ENGINE
3 - INCREASED ANGLE AS OIL STRIKES VANES
4 - DIRECTION STATOR IS LOCKED UP DUE TO OIL PUSHING
AGAINST STATOR VANES
Fig. 335 Checking Torque Converter Seating
1 - SCALE
2 - STRAIGHTEDGE
21 - 290 41TE AUTOMATIC TRANSAXLERS
TORQUE CONVERTER (Continued)
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OPERATION
The Transmission Range Sensor (TRS) (Fig. 337)
communicates shift lever position (SLP) to the TCM
as a combination of open and closed switches. Each
shift lever position has an assigned combination of
switch states (open/closed) that the TCM receives
from four sense circuits. The TCM interprets this
information and determines the appropriate trans-
axle gear position and shift schedule.
Since there are four switches, there are 16 possible
combinations of open and closed switches (codes).
Seven of these codes are related to gear position and
three are recognized as ªbetween gearº codes. This
results in six codes which should never occur. These
are called ªinvalidº codes. An invalid code will result
in a DTC, and the TCM will then determine the shift
lever position based on pressure switch data. This
allows reasonably normal transmission operation
with a TRS failure.
TRS SWITCH STATES
SLP T42 T41 T3 T1
PCL CL CL OP
RCL OP OP OP
NCL CL OP CL
ODOP OP OP CL
3OP OP CL OP
LCL OP CL CL
TRANSMISSION TEMPERATURE SENSOR
The TRS has an integrated thermistor (Fig. 338)
that the TCM uses to monitor the transmission's
sump temperature. Since fluid temperature can
affect transmission shift quality and convertor lock
up, the TCM requires this information to determine
which shift schedule to operate in. The PCM also
monitors this temperature data so it can energize the
vehicle cooling fan(s) when a transmission ªoverheatº
condition exists. If the thermistor circuit fails, the
TCM will revert to calculated oil temperature usage.
CALCULATED TEMPERATURE
A failure in the temperature sensor or circuit will
result in calculated temperature being substituted for
actual temperature. Calculated temperature is a pre-
dicted fluid temperature which is calculated from a
combination of inputs:
²Battery (ambient) temperature
²Engine coolant temperature
²In-gear run time since start-up
REMOVAL
(1) Remove valve body assembly from transaxle.
(Refer to 21 - TRANSMISSION/TRANSAXLE/AUTO-
MATIC - 41TE/VALVE BODY - REMOVAL)
(2) Remove transmission range sensor retaining
screw and remove sensor from valve body (Fig. 339).
(3) Remove TRS from manual shaft.
INSTALLATION
(1) Install transmission range sensor (TRS) to the
valve body and torque retaining screw (Fig. 339) to 5
N´m (45 in. lbs.).
(2) Install valve body to transaxle. (Refer to 21 -
TRANSMISSION/TRANSAXLE/AUTOMATIC -
41TE/VALVE BODY - INSTALLATION)
TRD LINK
DESCRIPTION
The Torque Reduction Link (TRD) is a wire
between the PCM and TCM that is used by the TCM
to request torque management. Torque management
controls or reduces torque output of the engine dur-
ing certain shift sequences, reducing torque applied
to the transaxle clutches.
OPERATION
The torque management signal is basically a
12-volt pull-up supplied by the PCM to the TCM over
the torque reduction link (TRD). Torque management
Fig. 339 Remove Transmission Range Sensor
1 - TRANSMISSION RANGE SENSOR
2 - MANUAL VALVE CONTROL PIN
3 - RETAINING SCREW
21 - 292 41TE AUTOMATIC TRANSAXLERS
TRANSMISSION RANGE SENSOR (Continued)
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