2004 DODGE TOWN AND COUNTRY low oil pressure

STATOR
The stator assembly (Fig. 321) 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. 322).
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. 323) 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.
OPERATION
The converter impeller (Fig. 324) (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.
Fig. 321 Stator Components
1 - CAM (OUTER RACE)
2 - ROLLER
3 - SPRING
4 - INNER RACE
Fig. 322 Stator Location
1-STATOR
2 - IMPELLER
3 - FLUID FLOW
4 - TURBINE
Fig. 323 Torque Converter Clutch (TCC)
1 - IMPELLER FRONT COVER
2 - THRUST WASHER ASSEMBLY
3 - IMPELLER
4-STATOR
5 - TURBINE
6 - PISTON
7 - FRICTION DISC
RS41TE AUTOMATIC TRANSAXLE21 - 245
TORQUE CONVERTER (Continued)

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. 325).
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 fluidthat 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.
Fig. 324 Torque Converter Fluid Operation
1 - APPLY PRESSURE 3 - RELEASE PRESSURE
2 - THE PISTON MOVES SLIGHTLY FORWARD 4 - THE PISTON MOVES SLIGHTLY REARWARD
Fig. 325 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
21 - 246 41TE AUTOMATIC TRANSAXLERS
TORQUE CONVERTER (Continued)

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
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. 329)
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:
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. 330).
(3) Remove TRS from manual shaft.
INSTALLATION
(1) Install transmission range sensor (TRS) to the
valve body and torque retaining screw (Fig. 330) 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
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.
Fig. 330 Remove Transmission Range Sensor
1 - TRANSMISSION RANGE SENSOR
2 - MANUAL VALVE CONTROL PIN
3 - RETAINING SCREW
RS41TE AUTOMATIC TRANSAXLE21 - 249
TRANSMISSION RANGE SENSOR (Continued)

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. 331):
²Regulator valve
²Solenoid switch valve
²Manual valve
²Converter 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
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.
Fig. 331 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
21 - 250 41TE AUTOMATIC TRANSAXLERS

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 PCM/TCM energizes or modulates the LR/CC
solenoid to apply the converter clutch piston, both
the converter 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
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. 332).
(6) Remove oil pan (Fig. 333).
Fig. 332 Oil Pan Bolts
1 - OIL PAN BOLTS (USE RTV UNDER BOLT HEADS)
Fig. 333 Oil Pan
1 - OIL PAN
2 - 1/8 INCH BEAD OF RTV SEALANT
3 - OIL FILTER
RS41TE AUTOMATIC TRANSAXLE21 - 251
VALVE BODY (Continued)

holding clutches: 2nd/4th gear and Low/Reverse. The
primary mechanical components of the transaxle con-
sist of the following:² Three multiple disc input clutches
² Two multiple disc holding clutches
² Four hydraulic accumulators
² Two planetary gear sets
² Hydraulic oil pump
² Valve body
² Solenoid/Pressure switch assembly
² Integral differential assembly
Control of the transaxle is accomplished by fully
adaptive electronics. Optimum shift scheduling is
accomplished through continuous real-time sensor
feedback information provided to the Powertrain
Control Module (PCM) or Transmission Control Mod-
ule (TCM). The PCM/TCM is the heart of the electronic control
system and relies on information from various direct
and indirect inputs (sensors, switches, etc.) to deter-
mine driver demand and vehicle operating condi-
tions. With this information, the PCM/TCM can
calculate and perform timely and quality shifts
through various output or control devices (solenoid
pack, transmission control relay, etc.). The PCM/TCM also performs certain self-diagnos-
tic functions and provides comprehensive information
(sensor data, DTC's, etc.) which is helpful in proper
diagnosis and repair. This information can be viewed
with the DRB scan tool.
TRANSAXLE IDENTIFICATION
The 40TE transaxle is identified by a barcode label
that is fixed to the transaxle case as shown in (Fig.
2). The label contains a series of digits that can be
translated into useful information such as transaxle
part number, date of manufacture, manufacturing
origin, plant shift number, build sequence number,
etc. Refer to (Fig. 3) for identification label break-
down. If the tag is not legible or missing, the ªPKº num-
ber, which is stamped into the transaxle case behind
the transfer gear cover, can be referred to for identi-
fication. This number differs slightly in that it con-
tains the entire transaxle part number, rather than
the last three digits.
Fig. 2 Transaxle Identification Label
1 - IDENTIFICATION LABEL
Fig. 3 Identification Label Breakdown
1 - T=TRACEABILITY
2 - SUPPLIER CODE (PK=KOKOMO)
3 - COMPONENT CODE (TK=KOKOMO TRANSMISSION)
4 - BUILD DAY (344=DEC. 9)
5 - BUILD YEAR (9=1999)
6 - LINE/SHIFT CODE (3=3RD SHIFT)
7 - BUILD SEQUENCE NUMBER
8 - LAST THREE OF P/N
9 - ALPHA
10 - TRANSAXLE PART NUMBER
11 - P=PART NUMBER
21s - 26 40TE AUTOMATIC TRANSAXLERS
40TE AUTOMATIC TRANSAXLE (Continued)

DIAGNOSIS AND TESTING - CLUTCH AIR
PRESSURE TESTS
Inoperative clutches can be located using a series
of tests by substituting air pressure for fluid pressure
(Fig. 5) (Fig. 6). The clutches may be tested by apply-
ing air pressure to their respective passages. The
valve body must be removed and Tool 6056 installed.
To make air pressure tests, proceed as follows:
NOTE: The compressed air supply must be free of
all dirt and moisture. Use a pressure of 30 psi.
Remove oil pan and valve body. See Valve body
removal.
OVERDRIVE CLUTCH
Apply air pressure to the overdrive clutch apply
passage and watch for the push/pull piston to move
forward. The piston should return to its starting
position when the air pressure is removed.
REVERSE CLUTCH
Apply air pressure to the reverse clutch apply pas-
sage and watch for the push/pull piston to move rear-
ward. The piston should return to its starting
position when the air pressure is removed.
2/4 CLUTCH
Apply air pressure to the feed hole located on the
2/4 clutch retainer. Look in the area where the 2/4 piston contacts the first separator plate and watch
carefully for the 2/4 piston to move rearward. The
piston should return to its original position after the
air pressure is removed.
LOW/REVERSE CLUTCH
Apply air pressure to the low/reverse clutch feed
hole (rear of case, between 2 bolt holes). Then, look
in the area where the low/reverse piston contacts the
first separator plate. Watch carefully for the piston to
move forward. The piston should return to its origi-
nal position after the air pressure is removed.
UNDERDRIVE CLUTCH
Because this clutch piston cannot be seen, its oper-
ation is checked by function. Air pressure is applied
to the low/reverse and the 2/4 clutches. This locks the
output shaft. Use a piece of rubber hose wrapped
around the input shaft and a pair of clamp-on pliers
to turn the input shaft. Next apply air pressure to
the underdrive clutch. The input shaft should not
rotate with hand torque. Release the air pressure
and confirm that the input shaft will rotate.
Fig. 5 Air Pressure Test Plate
1 - TOOL 6056
2 - ACCUMULATORS
Fig. 6 Testing Reverse Clutch
1 - TOOL 6056
2 - AIR NOZZLE
21s - 30 40TE AUTOMATIC TRANSAXLERS
40TE AUTOMATIC TRANSAXLE (Continued)

(27) Lower engine/transaxle assembly with screw
jack. (28) Obtain helper and/or transmission jack.
Secure transmission jack to transaxle assembly. (29) Remove upper mount bracket from transaxle
(Fig. 14). (30) Remove remaining transaxle bellhousing-to-
engine bolts. (31) Remove transaxle assembly from vehicle.
DISASSEMBLY
NOTE: If transaxle is being overhauled (clutch
and/or seal replacement) or replaced, it is neces-
sary to perform the PCM/TCM Quick Learn Proce-
dure. (Refer t o 8 - ELECTRICAL/ELECTRONIC
CONTROL MODULES/POWERTRAIN/TRANSMIS-
SION CONTROL MODULE - STANDARD PROCE-
DURE)
NOTE: This procedure does not include final drive
(differential) disassembly.
(1) Remove input and output speed sensors.
(2) Remove three (3) solenoid/pressure switch
assembly-to-case bolts. (3) Remove solenoid/pressure switch assembly and
gasket (Fig. 15). (4) Remove oil pan-to-case bolts (Fig. 16).
(5) Remove oil pan (Fig. 17).
Fig. 15 Solenoid/Pressure Switch Assembly and
Gasket
1 - SOLENOID/PRESSURE SWITCH ASSEMBLY
2 - GASKET
Fig. 16 Remove Oil Pan Bolts
1 - OIL PAN BOLTS (USE RTV UNDER BOLT HEADS)
Fig. 17 Remove Oil Pan
1 - OIL PAN
2 - 1/8 INCH BEAD OF MOPAR TATF RTV (MS-GF41)
3 - OIL FILTER
21s - 34 40TE AUTOMATIC TRANSAXLERS
40TE AUTOMATIC TRANSAXLE (Continued)