clutch CHRYSLER CARAVAN 2002 Service Manual
Page 1850 of 2399
is requested when the TCM pulses this signal to
ground. The PCM recognizes this request and
responds by retarding ignition timing, killing fuel
injectors, etc. The PCM sends a confirmation of the
request to the TCM via the communication bus.
Torque reduction is not noticable by the driver, and
usually lasts for a very short period of time.
If the confirmation signal is not received by the
TCM after two sequential request messages, a diag-
nostic trouble code will be set.
VALVE BODY
DESCRIPTION
The valve body assembly consists of a cast alumi-
num valve body, a separator plate, and transfer
plate. The valve body contains valves and check balls
that control fluid delivery to the torque converter
clutch, solenoid/pressure switch assembly, and fric-
tional clutches. The valve body contains the following
components (Fig. 340):
²Regulator valve
²Solenoid switch valve
²Manual valve²Converter clutch switch valve
²Converter clutch control valve
²Torque converter regulator valve
²Low/Reverse switch valve
In addition, the valve body also contains the ther-
mal valve, #2,3&4 check balls, the #5 (overdrive)
check valve and the 2/4 accumulator assembly. (Refer
to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC
- 41TE/VALVE BODY - DISASSEMBLY)
OPERATION
NOTE: Refer to the Hydraulic Schematics for a
visual aid in determining valve location, operation
and design.
REGULATOR VALVE
The regulator valve controls hydraulic pressure in
the transaxle. It receives unregulated pressure from
the pump, which works against spring tension to
maintain oil at specific pressures. A system of sleeves
and ports allows the regulator valve to work at one of
three predetermined pressure levels. Regulated oil
pressure is also referred to as ªline pressure.º
Fig. 340 Valve Body Assembly
1 - VALVE BODY 5 - MANUAL VALVE
2 - T/C REGULATOR VALVE 6 - CONVERTER CLUTCH SWITCH VALVE
3 - L/R SWITCH VALVE 7 - SOLENOID SWITCH VALVE
4 - CONVERTER CLUTCH CONTROL VALVE 8 - REGULATOR VALVE
RS41TE AUTOMATIC TRANSAXLE21 - 293
TRD LINK (Continued)
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SOLENOID SWITCH VALVE
The solenoid switch valve controls line pressure
from the LR/CC solenoid. In one position, it allows
the low/reverse clutch to be pressurized. In the other,
it directs line pressure to the converter control and
converter clutch valves.
MANUAL VALVE
The manual valve is operated by the mechanical
shift linkage. Its primary responsibility is to send
line pressure to the appropriate hydraulic circuits
and solenoids. The valve has three operating ranges
or positions.
CONVERTER CLUTCH SWITCH VALVE
The main responsibility of the converter clutch switch
valve is to control hydraulic pressure applied to the front
(off) side of the converter clutch piston. Line pressure
from the regulator valve is fed to the torque converter
regulator valve, where it passes through the valve, and is
slightly regulated. The pressure is then directed to the
converter clutch switch valve and to the front side of the
converter clutch piston. This pressure pushes the piston
back and disengages the converter clutch.
CONVERTER CLUTCH CONTROL VALVE
The converter clutch control valve controls the
back (on) side of the torque converter clutch. When
the TCM energizes or modulates the LR/CC solenoid
to apply the converter clutch piston, both the con-
verter clutch control valve and the converter control
valve move, allowing pressure to be applied to the
back side of the clutch.
T/C REGULATOR VALVE
The torque converter regulator valve slightly regu-
lates the flow of fluid to the torque converter.
LOW/REVERSE SWITCH VALVE
The low/reverse clutch is applied from different
sources, depending on whether low (1st) gear or
reverse is selected. The low/reverse switch valve
alternates positions depending on from which direc-
tion fluid pressure is applied. By design, when the
valve is shifted by fluid pressure from one channel,
the opposing channel is blocked. The switch valve
alienates the possibility of a sticking ball check, thus
providing consistent application of the low/reverse
clutch under all operating conditions.
REMOVAL
REMOVAL
NOTE: If valve body is replaced or reconditioned,
the TCM Quick Learn Procedure must be per-formed. (Refer to 8 - ELECTRICAL/ELECTRONIC
CONTROL MODULES/TRANSMISSION CONTROL
MODULE - STANDARD PROCEDURE)
(1) Disconnect battery negative cable.
(2) Disconnect gearshift cable from manual valve
lever.
(3) Remove manual valve lever from manual shaft.
(4) Raise vehicle on hoist.
(5) Remove oil pan bolts (Fig. 341).
(6) Remove oil pan (Fig. 342).
Fig. 341 Oil Pan Bolts
1 - OIL PAN BOLTS (USE RTV UNDER BOLT HEADS)
Fig. 342 Oil Pan
1 - OIL PAN
2 - 1/8 INCH BEAD OF RTV SEALANT
3 - OIL FILTER
21 - 294 41TE AUTOMATIC TRANSAXLERS
VALVE BODY (Continued)
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(7) Invert assembly and remove Transfer Plate
(Fig. 359). Beware of loose check balls.
(8) Remove oil screen (Fig. 360).(9) Remove the overdrive clutch (#5) check valve
(Fig. 361)
(10) Remove separator plate (Fig. 362).
Fig. 359 Remove Transfer Plate
1 - TRANSFER PLATE
Fig. 360 Remove Oil Screen
1 - OIL SCREEN
Fig. 361 Remove Overdrive Clutch (#5) Check Valve
1 - OVERDRIVE CLUTCH (#5) CHECK VALVE
Fig. 362 Remove Separator Plate
1 - SEPARATOR PLATE
2 - VALVE BODY
RS41TE AUTOMATIC TRANSAXLE21 - 299
VALVE BODY (Continued)
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Fig. 368 Springs and Valves Location
1 - VALVE BODY 5 - MANUAL VALVE
2 - T/C REGULATOR VALVE 6 - CONVERTER CLUTCH SWITCH VALVE
3 - L/R SWITCH VALVE 7 - SOLENOID SWITCH VALVE
4 - CONVERTER CLUTCH CONTROL VALVE 8 - REGULATOR VALVE
Fig. 369 Install Regulator Valve Spring Retainer
using Tool 6302
1 - TOOL 6302
2 - RETAINER
Fig. 370 Install Dual Retainer Plate using Tool 6301
1 - TOOL 6301
2 - RETAINER
21 - 302 41TE AUTOMATIC TRANSAXLERS
VALVE BODY (Continued)
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(6) Install thermal valve into transfer plate (Fig.
373).
(7) Install separator plate to valve body (Fig. 374).(8) Install the overdrive clutch (#5) check valve to
separator plate (Fig. 375)
(9) Install oil screen to separator plate (Fig. 376).
Fig. 373 Install Thermal Valve
1 - THERMAL VALVE
Fig. 374 Install Separator Plate
1 - SEPARATOR PLATE
2 - VALVE BODY
Fig. 375 Install Overdrive Clutch (#5) Check Valve
1 - OVERDRIVE CLUTCH (#5) CHECK VALVE
Fig. 376 Install Oil Screen
1 - OIL SCREEN
21 - 304 41TE AUTOMATIC TRANSAXLERS
VALVE BODY (Continued)
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OPERATION
NEUTRAL
Engine power is transmitted to the input shaft via
the clutch assembly and the input shaft turns. Since
no synchronizers are engaged on either the input or
intermediate shafts, power is not transmitted to the
intermediate shaft and the differential does not turn
(Fig. 3).
Fig. 3 Neutral Gear Operation
RST850 MANUAL TRANSAXLE21 - 311
T850 MANUAL TRANSAXLE (Continued)
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1ST GEAR
Engine power is transmitted to the input shaft via
the clutch assembly and the input shaft turns. The
input shaft first gear is integral to the input shaft,
and is in constant mesh with the intermediate shaft
first speed gear. Because of this constant mesh, the
intermediate shaft first speed gear freewheels until
first gear is selected. As the gearshift lever is moved
to the first gear position, the 1-2 fork moves the 1-2
synchronizer sleeve towards first gear on the inter-
mediate shaft. The synchronizer sleeve engages the
first gear clutch teeth, fixing the gear to the interme-
diate shaft, and allowing power to transmit through
the intermediate shaft to the differential (Fig. 4).
Fig. 4 1st Gear Operation
21 - 312 T850 MANUAL TRANSAXLERS
T850 MANUAL TRANSAXLE (Continued)
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2ND GEAR
Engine power is transmitted to the input shaft via
the clutch assembly and the input shaft turns. The
input shaft second gear is integral to the input shaft,
and is in constant mesh with the intermediate shaft
second speed gear. Because of this constant mesh,
the intermediate shaft second speed gear freewheels
until second gear is selected. As the gearshift lever is
moved to the second gear position, the 1-2 fork moves
the 1-2 synchronizer sleeve towards second gear on
the intermediate shaft. The synchronizer sleeve
engages the second gear clutch teeth, fixing the gear
to the intermediate shaft, and allowing power to
transmit through the intermediate shaft to the differ-
ential (Fig. 5).
Fig. 5 2nd Gear Operation
RST850 MANUAL TRANSAXLE21 - 313
T850 MANUAL TRANSAXLE (Continued)
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3RD GEAR
Engine power is transmitted to the input shaft via
the clutch assembly and the input shaft turns. The
input shaft third speed gear is in constant mesh with
the intermediate shaft 3-4 cluster gear, which is fixed
to the intermediate shaft. Because of this constant
mesh, the input shaft third speed gear freewheels
until third gear is selected. As the gearshift lever is
moved to the third gear position, the 3-4 fork moves
the 3-4 synchronizer sleeve towards third gear on the
input shaft. The synchronizer sleeve engages the
third gear clutch teeth, fixing the gear to the input
shaft, and allowing power to transmit through the
intermediate shaft to the differential (Fig. 6).
Fig. 6 3rd Gear Operation
21 - 314 T850 MANUAL TRANSAXLERS
T850 MANUAL TRANSAXLE (Continued)
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4TH GEAR
Engine power is transmitted to the input shaft via
the clutch assembly and the input shaft turns. The
input shaft fourth speed gear is in constant mesh
with the intermediate shaft 3-4 cluster gear, which is
fixed to the intermediate shaft. Because of this con-
stant mesh, the input shaft fourth speed gear free-
wheels until fourth gear is selected. As the gearshift
lever is moved to the fourth gear position, the 3-4
fork moves the 3-4 synchronizer sleeve towards
fourth gear on the input shaft. The synchronizer
sleeve engages the fourth gear clutch teeth, fixing
the gear to the input shaft, and allowing power to
transmit through the intermediate shaft to the differ-
ential (Fig. 7).
Fig. 7 4th Gear Operation
RST850 MANUAL TRANSAXLE21 - 315
T850 MANUAL TRANSAXLE (Continued)
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