Page 1889 of 2585

The process of elimination can be used to detect
any unit which slips and to confirm proper operation
of good units. Road test analysis can diagnose slip-
ping units, but the cause of the malfunction cannot
be determined. Practically any condition can be
caused by leaking hydraulic circuits or sticking
valves.
DIAGNOSIS AND TESTING - HYDRAULIC
PRESSURE TESTS
Pressure testing is a very important step in the
diagnostic procedure. These tests usually reveal the
cause of most hydraulic transaxle problems. Before performing pressure tests, be certain that
fluid level and condition, and shift cable adjustments
have been checked and approved. Fluid must be at
operating temperature (150 to 200 degrees F.). Install an engine tachometer, raise vehicle on hoist
which allows front wheels to turn, and position
tachometer so it can be read. Attach 300 psi gauge (C-3293SP) to port(s)
required for test(s) being conducted. Use adapter set
L-4559 to adapt gauge(s) to transaxle. Test port locations are shown in (Fig. 4).
TEST ONE-SELECTOR IN LOW (1st GEAR)
(1) Attach pressure gauge to the low/reverse clutch
tap. (2) Move selector lever to the (L) position.
(3) Allow vehicle wheels to turn and increase
throttle opening to achieve an indicated vehicle speed
to 20 mph. (4) Low/reverse clutch pressure should read 115 to
145 psi. (5) This test checks pump output, pressure regula-
tion and condition of the low/reverse clutch hydraulic
circuit and shift schedule.
TEST TWO-SELECTOR IN DRIVE (2nd GEAR)
NOTE: This test checks the underdrive clutch
hydraulic circuit as well as the shift schedule.
(1) Attach gauge to the underdrive clutch tap.
(2) Move selector lever to the 3 position.
(3) Allow vehicle wheels to turn and increase
throttle opening to achieve an indicated vehicle speed
of 30 mph. (4) In second gear the underdrive clutch pressure
should read 110 to 145 psi.
TEST TWO A±SELECTOR IN OD (4th Gear)
NOTE: This test checks the underdrive clutch
hydraulic circuit as well as the shift schedule.
(1) Attach gauge to the underdrive clutch tap.
(2) Move selector lever to the (OD) position.
(3) Allow wheels to rotate freely and increase
throttle opening to achieve an indicated speed of 40
mph. (4) Underdrive clutch pressure should read below
5 psi. If not, then either the solenoid assembly or
PCM/TCM is at fault.
TEST THREE-OVERDRIVE CLUTCH CHECK (3rd and
2nd Gear)
(1) Attach gauge to the overdrive clutch tap.
(2) Move selector lever to the (OD) position.
(3) Allow vehicle wheels to turn and increase
throttle opening to achieve an indicated vehicle speed
of 20 mph. Vehicle should be in 3rd gear. (4) Overdrive clutch pressure should read 74 to 95
psi. (5) Move selector lever to the (3) position and
increase indicated vehicle speed to 30 mph. (6) The vehicle should be in second gear and over-
drive clutch pressure should be less than 5 psi. (7) This test checks the overdrive clutch hydraulic
circuit as well as the shift schedule.
TEST FOUR-SELECTOR IN OVERDRIVE (4th Gear)
(1) Attach gauge to the 2/4 clutch tap.
(2) Move selector lever to the (OD) position.
(3) Allow vehicle front wheels to turn and increase
throttle opening to achieve an indicated vehicle speed
of 30 mph. Vehicle should be in 4th gear. (4) The 2/4 clutch pressure should read 75 to 95
psi. (5) This test checks the 2/4 clutch hydraulic cir-
cuit.
Fig. 4 Pressure Taps
1 - OVERDRIVE CLUTCH
2 - TORQUE CONVERTER OFF
3 - LOW/REVERSE CLUTCH
4 - 2/4 CLUTCH
5 - REVERSE CLUTCH
6 - UNDERDRIVE CLUTCH
21s - 28 40TE AUTOMATIC TRANSAXLERS
40TE AUTOMATIC TRANSAXLE (Continued)
Page 1890 of 2585

TEST FIVE-SELECTOR IN OVERDRIVE (4th Gear-CC
on)
(1) Attach gauge to the torque converter clutch off
pressure tap. (2) Move selector lever to the (OD) position.
(3) Allow vehicle wheels to turn and increase
throttle opening to achieve an indicated vehicle speed
of 50 mph. Vehicle should be in 4th gear, CC on.
CAUTION: Both wheels must turn at the same
speed.
(4) Torque converter clutch off pressure should be
less than 5 psi. (5) This test checks the torque converter clutch
hydraulic circuit.
TEST SIX-SELECTOR IN REVERSE
(1) Attach gauges to the reverse and LR clutch
tap. (2) Move selector lever to the (R) position.
(3) Read reverse clutch pressure with output sta-
tionary (foot on brake) and throttle opened to achieve
1500 rpm. (4) Reverse and LR clutch pressure should read
165 to 235 psi. (5) This test checks the reverse clutch hydraulic
circuit.
TEST RESULT INDICATIONS
(1) If proper line pressure is found in any one test,
the pump and pressure regulator are working prop-
erly. (2) Low pressure in all positions indicates a defec-
tive pump, a clogged filter, or a stuck pressure regu-
lator valve. (3) Clutch circuit leaks are indicated if pressures
do not fall within the specified pressure range. (4) If the overdrive clutch pressure is greater than
5 psi in Step 4 of Test Three, a worn reaction shaft
seal ring or a defective solenoid assembly is indi-
cated. (5) If the underdrive clutch pressure is greater
than 5 psi in Step 4 of Test Two A, a defective sole-
noid assembly or PCM/TCM is the cause.
PRESSURE CHECK SPECIFICATIONS
Pressure Taps
Gear
Selector
Position Actual Gear
Underdrive
Clutch Overdrive
Clutch Reverse
Clutch Torque
Converter
Clutch Off 2/4 Clutch Low/
Reverse Clutch
Park * PARK 0-2 0-5 0-2 60-110 0-2 115-145
0 mph
REVERSE * REVERSE 0-2 0-7 165-235 50-100 0-2 165-235
0 mph
NEUTRAL * NEUTRAL 0-2 0-5 0-2 60-110 0-2 115-145
0 mph
L# FIRST 110-145 0-5 0-2 60-110 0-2 115-145
20 mph
3# SECOND 110-145 0-5 0-2 60-110 115-145 0-2
30 mph
3# DIRECT 75-95 75-95 0-2 60-90 0-2 0-2
45 mph
OD # OVERDRIVE 0-2 75-95 0-2 60-90 75-95 0-2
30 mph
OD # OVERDRIVE
WITH TCC 0-2 75-95 0-2 0-5 75-95 0-2
50 mph
* Engine speed at 1500 rpm
# CAUTION: Both front wheels must be turning at the same speed.
RS 40TE AUTOMATIC TRANSAXLE21s-29
40TE AUTOMATIC TRANSAXLE (Continued)
Page 1891 of 2585

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)
Page 1892 of 2585

DIAGNOSIS AND TESTING - TORQUE
CONVERTER HOUSING FLUID LEAKAGE
When diagnosing converter housing fluid leaks,
three actions must be taken before repair: (1) Verify proper transmission fluid level.
(2) Verify that the leak originates from the con-
verter housing area and is transmission fluid. (3) Determine the true source of the leak.
Fluid leakage at or around the torque converter
area may originate from an engine oil leak (Fig. 7).
The area should be examined closely. Factory fill
fluid is red and, therefore, can be distinguished from
engine oil.
Some suspected converter housing fluid leaks may not
be leaks at all. They may only be the result of residual
fluid in the converter housing, or excess fluid spilled
during factory fill, or fill after repair. Converter housing
leaks have several potential sources. Through careful
observation, a leak source can be identified before
removing the transmission for repair. Pump seal leaks tend to move along the drive hub
and onto the rear of the converter (Fig. 7). Pump o-ring
or pump body leaks follow the same path as a seal leak.
Pump attaching bolt leaks are generally deposited on
the inside of the converter housing and not on the con-
verter itself. Pump seal or gasket leaks usually travel
down the inside of the converter housing (Fig. 7).
TORQUE CONVERTER LEAKAGE
Possible sources of torque converter leakage are:
² Torque converter weld leaks at the outside diam-
eter weld (Fig. 8). ²
Torque converter hub weld (Fig. 8).
REMOVAL
NOTE: If transaxle assembly is being replaced or
overhauled (clutch and/or seal replacement), it is
necessary to perform the TCM Quick Learn Proce-
dure. (Refer t o 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/TRANSMISSION CONTROL
MODULE - STANDARD PROCEDURE)
(1) Disconnect battery cables.
(2) Remove battery shield (Fig. 9).
Fig. 7 Converter Housing Leak Paths
1 - PUMP SEAL
2 - PUMP VENT
3 - PUMP BOLT
4 - PUMP GASKET
5 - CONVERTER HOUSING
6 - CONVERTER
7 - REAR MAIN SEAL LEAK
Fig. 8 Converter Leak Points - Typical
1 - OUTSIDE DIAMETER WELD
2 - TORQUE CONVERTER HUB WELD
3 - STARTER RING GEAR
4 - LUG
Fig. 9 Battery Thermal Guard
1 - BATTERY THERMOWRAP (IF EQUIPPED)
2 - INTEGRATED POWER MODULE
3 - FRONT CONTROL MODULE
RS 40TE AUTOMATIC TRANSAXLE21s-31
40TE AUTOMATIC TRANSAXLE (Continued)
Page 1893 of 2585

(3) Remove coolant recovery bottle (Fig. 10).
(4) Remove fluid level indicator/tube assembly.
Plug opening to prevent debris from entering trans-
axle. (5) Using a blade or suitable hose cutter, cut trans-
axle oil cooler lines off flush with fittings. Plug lines
and fittings to prevent debris from entering transaxle
or cooler circuit. A service splice kit will be installed
upon reassembly. (6) Disconnect input and output shaft speed sensor
connectors (Fig. 11). (7) Disconnect transmission range sensor (TRS)
connector (Fig. 11). (8) Disconnect solenoid/pressure switch assembly
connector (Fig. 11). (9) Disconnect gear shift cable from manual valve
lever and upper mount bracket (Fig. 12). (10) Disconnect crankshaft position sensor (if
equipped). Remove sensor from bellhousing. (11) Reposition leak detection pump harness and
hoses.
Fig. 10 Coolant Recovery Bottle
1 - COOLANT RECOVERY CONTAINER
2 - HOSE
3 - BOLT
4 - SUB FRAME RAIL
Fig. 11 Component Connector LocationÐTypical
1 - SOLENOID/PRESSURE SWITCH ASSY. CONNECTOR
2 - INPUT SPEED SENSOR CONNECTOR
3 - OUTPUT SPEED SENSOR CONNECTOR
4 - TRANSMISSION RANGE SENSOR CONNECTOR
Fig. 12 Gearshift Cable at Transaxle - Typical
1 - MANUAL VALVE LEVER
2 - GEAR SHIFT CABLE
3 - UPPER MOUNT BRACKET
21s - 32 40TE AUTOMATIC TRANSAXLERS
40TE AUTOMATIC TRANSAXLE (Continued)
Page 1894 of 2585

(12) Remove rear mount bracket-to-transaxle case
bolts (Fig. 13). (13) Remove transaxle upper bellhousing-to-block
bolts. (14) Raise vehicle on hoist.
(15) Remove transaxle oil pan and drain fluid into
suitable container. (16) Remove front wheel/tire assemblies.
(17) Remove left and right halfshaft assemblies.
(Refer t o 3 - DIFFERENTIAL & DRIVELINE/HALF
SHAFT - REMOVAL) (18) AWD models: Remove power transfer unit.
(Refer to 21 - TRANSMISSION/TRANSAXLE/
POWER TRANSFER UNIT - REMOVAL) (19) Remove rear mount bracket-to-transaxle case
lower (horizontal) bolt (Fig. 13). (20) Remove front mount/bracket assembly.
(21) Remove starter motor.
(22) Remove lateral bending brace.
(23) Remove inspection cover.
(24) Remove torque converter-to-drive plate bolts.
(25) Support engine/transaxle assembly at engine
oil pan with screw jack and wood block. (26) Partially remove left wheelhouse splash shield
to gain access to and remove upper mount thru-bolt
(Fig. 14).
Fig. 13 Rear Mount Bracket - Typical
1 - BOLT - VERTICAL
2 - BRACKET - REAR MOUNT 3 - BOLT - HORIZONTAL
Fig. 14 Left Mount-to-Bracket
1 - BOLT - BRACKET TO FRAME RAIL
2 - BOLT - MOUNT TO RAIL THROUGH
3 - BOLT - LEFT MOUNT TO TRANSAXLE
4 - TRANSAXLE
5 - MOUNT - LEFT
6 - BRACKET - LEFT MOUNT
RS
40TE AUTOMATIC TRANSAXLE21s-33
40TE AUTOMATIC TRANSAXLE (Continued)
Page 1895 of 2585

(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)
Page 1896 of 2585

(6) Remove oil filter (Fig. 18).
(7) Turn manual valve fully clock-wise to get park
rod into position for removal. (8) Remove valve body-to-case bolts (Fig. 19). 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. 20) and remove valve
body assembly (Fig. 21).
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.
Fig. 18 Remove Filter and O-Ring
1 - OIL FILTER
2 - O-RING
Fig. 19 Remove Valve Body-to-Case Bolts
1 - VALVE BODY ATTACHING BOLTS (18)
2 - VALVE BODY
Fig. 20 Push Park Rod Rollers from Guide Bracket
1 - PARK SPRAG ROLLERS
2 - SCREWDRIVER
3 - PARK SPRAG GUIDE BRACKET
Fig. 21 Valve Body Removal/Installation
1 - VALVE BODY
RS 40TE AUTOMATIC TRANSAXLE21s-35
40TE AUTOMATIC TRANSAXLE (Continued)