2004 CHRYSLER VOYAGER engine

TORQUE CONVERTER
DESCRIPTION
The torque converter (Fig. 293) 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.
Fig. 293 Torque Converter Assembly
1 - TURBINE
2 - IMPELLER
3 - HUB
4-STATOR
5 - CONVERTER CLUTCH DISC
6 - DRIVE PLATE
21s - 144 40TE AUTOMATIC TRANSAXLERS

IMPELLER
The impeller (Fig. 294) is an integral part of the
converter housing. The impeller consists of curved
blades placed radially along the inside of the housing
on the transmission side of the converter. As the con-
verter housing is rotated by the engine, so is the
impeller, because they are one and the same and are
the driving member of the system.
Fig. 294 Impeller
1 - ENGINE FLEXPLATE 4 - ENGINE ROTATION
2 - OIL FLOW FROM IMPELLER SECTION INTO TURBINE
SECTION 5 - ENGINE ROTATION
3 - IMPELLER VANES AND COVER ARE INTEGRAL
RS 40TE AUTOMATIC TRANSAXLE21s - 145
TORQUE CONVERTER (Continued)

TURBINE
The turbine (Fig. 295) is the output, or driven,
member of the converter. The turbine is mounted
within the housing opposite the impeller, but is not
attached to the housing. The input shaft is inserted
through the center of the impeller and splined into
the turbine. The design of the turbine is similar to
the impeller, except the blades of the turbine are
curved in the opposite direction.
Fig. 295 Turbine
1 - TURBINE VANE
2 - ENGINE ROTATION
3 - INPUT SHAFT 4 - PORTION OF TORQUE CONVERTER COVER
5 - ENGINE ROTATION
6 - OIL FLOW WITHIN TURBINE SECTION
21s - 146 40TE AUTOMATIC TRANSAXLERS
TORQUE CONVERTER (Continued)

OPERATION
The converter impeller (Fig. 299) (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.
Fig. 299 Torque Converter Fluid Operation
1 - APPLY PRESSURE 3 - RELEASE PRESSURE
2 - THE PISTON MOVES SLIGHTLY FORWARD 4 - THE PISTON MOVES SLIGHTLY REARWARD
21s - 148 40TE AUTOMATIC TRANSAXLERS
TORQUE CONVERTER (Continued)

STATOR
Torque multiplication is achieved by locking the
stator's over-running clutch to its shaft (Fig. 300).
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 stator
from 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
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. 301). 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)
Fig. 300 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
RS 40TE AUTOMATIC TRANSAXLE21s - 149
TORQUE CONVERTER (Continued)

(9)Fill the transmission with the recommended fluid.
(Refer to 21 - TRANSMISSION/TRANSAXLE/AUTO-
MATIC - 41TE/FLUID - STANDARD PROCEDURE)
TRANSMISSION CONTROL RELAY
DESCRIPTION
The transmission control relay (Fig. 302) is located
in the Intelligent Power Module (IPM), which is
located on the left side of the engine compartment
between the battery and left fender.
OPERATION
The Transmission Control Relay is supplied fused
B+ voltage, energized by the PCM, and is used to
supply power to the solenoid pack when the trans-
mission is in normal operating mode. When the relay
is ªoffº, no power is supplied to the solenoid pack and
the transmission is in ªlimp-inº mode. After a control-
ler reset (ignition key turned to the ªrunº position or
after cranking engine), the PCM energizes the relay.
Prior to this, the PCM verifies that the contacts are
open by checking for no voltage at the switched bat-
tery terminals. After this is verified, the voltage at
the solenoid pack pressure switches is checked. After
the relay is energized, the PCM monitors the termi-
nals to verify that the voltage is greater than 3 volts.
TRANSMISSION RANGE SENSOR
DESCRIPTION
The Transmission Range Sensor (TRS) is mounted
to the top of the valve body inside the transaxle and can only be serviced by removing the valve body. The
electrical connector extends through the transaxle
case (Fig. 303).
The Transmission Range Sensor (TRS) has four
switch contacts that monitor shift lever position and
send the information to the PCM/TCM.
Fig. 301 Checking Torque Converter Seating
1 - SCALE
2 - STRAIGHTEDGE
Fig. 302 Transmission Control Relay Location
1 - TRANSMISSION CONTROL RELAY
2 - LEFT FENDER
3 - INTELLIGENT POWER MODULE (IPM)
4 - BATTERY
Fig. 303 Transmission Range Sensor (TRS) Location
1 - TRANSMISSION RANGE SENSOR
21s - 150 40TE AUTOMATIC TRANSAXLERS
TORQUE CONVERTER (Continued)

The TRS also has an integrated temperature sen-
sor (thermistor) that communicates transaxle tem-
perature to the TCM and PCM (Fig. 304).
OPERATION
The Transmission Range Sensor (TRS) (Fig. 303) com-
municates shift lever position (SLP) to the PCM/TCM as
a combination of open and closed switches. Each shift
lever position has an assigned combination of switch
states (open/closed) that the PCM/TCM receives from
four sense circuits. The PCM/TCM interprets this infor-
mation and determines the appropriate transaxle 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 PCM/TCM will then determine the
shift lever position based on pressure switch data.
This allows reasonably normal transmission opera-
tion with a TRS failure.
TRS SWITCH STATES
SLP T42 T41 T3 T1
P CL CL CL OP
R CL OP OP OP
N CL CL OP CL
OD OP OP OP CL
3 OP OP CL OP
L CL OP CL CL
TRANSMISSION TEMPERATURE SENSOR
The TRS has an integrated thermistor (Fig. 304)
that the PCM/TCM uses to monitor the transmis-
sion's sump temperature. Since fluid temperature
can affect transmission shift quality and convertor
lock up, the PCM/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 transmis-
sion ªoverheatº condition exists. If the thermistor cir-
cuit fails, the PCM/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: ² Battery (ambient) temperature
² Engine coolant temperature
² In-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. 305).
(3) Remove TRS from manual shaft.
Fig. 304 Transmission Temperature Sensor
1 - TRANSMISSION RANGE SENSOR
2 - TEMPERATURE SENSOR
Fig. 305 Remove Transmission Range Sensor
1 - TRANSMISSION RANGE SENSOR
2 - MANUAL VALVE CONTROL PIN
3 - RETAINING SCREW
RS 40TE AUTOMATIC TRANSAXLE21s - 151
TRANSMISSION RANGE SENSOR (Continued)

CAUTION: Do not handle the valve body assembly
from the manual valve. Damage can result.(9) Using a screwdriver, push park rod rollers
away from guide bracket (Fig. 6) and remove valve
body assembly (Fig. 7).
NOTE: Depending on engine application, some
accumulators will have two springs and others will
have one spring. The springs are color-coded
according to application and year. When disassem-
bling, mark accumulator spring location to ease
assembly. (10) Remove underdrive and overdrive accumula-
tors (Fig. 8).
(11) Remove low/reverse accumulator snap ring
(Fig. 9).
Fig. 6 Push Park Rod Rollers from Guide Bracket
1 - PARK SPRAG ROLLERS
2 - SCREWDRIVER
3 - PARK SPRAG GUIDE BRACKET
Fig. 7 Remove Valve Body
1 - VALVE BODY
Fig. 8 Underdrive and Overdrive Accumulators
1 - OVERDRIVE PISTON AND SPRING
2 - UNDERDRIVE PISTON AND SPRING
Fig. 9 Remove Low/Reverse Accumulator Snap Ring
1 - SNAP RING
2 - PLUG
21s - 168 41TE AUTOMATIC TRANSAXLERS
41TE AUTOMATIC TRANSAXLE (Continued)