piston JEEP GRAND CHEROKEE 2003 WJ / 2.G Workshop Manual

INSTALLATION........................253
OUTPUT SPEED SENSOR
DESCRIPTION........................254
OPERATION..........................254
REMOVAL............................254
INSTALLATION........................254
OVERDRIVE SWITCH
DESCRIPTION........................254
OPERATION..........................254
PARK LOCK CABLE
REMOVAL............................255
INSTALLATION........................255
PISTONS
DESCRIPTION........................256
OPERATION..........................256
PLANETARY GEARTRAIN
DESCRIPTION........................258
OPERATION..........................260
DISASSEMBLY........................260
CLEANING...........................260
INSPECTION.........................260
ASSEMBLY...........................261
SHIFT MECHANISM
DESCRIPTION........................261
OPERATION..........................261
REMOVAL............................261
INSTALLATION........................263
SOLENOID SWITCH VALVE
DESCRIPTION........................263
OPERATION..........................263
SOLENOIDS
DESCRIPTION........................263OPERATION..........................264
TORQUE CONVERTER
DESCRIPTION........................264
OPERATION..........................268
REMOVAL............................269
INSTALLATION........................269
TRANSMISSION CONTROL RELAY
DESCRIPTION........................270
OPERATION..........................270
TRANSMISSION RANGE SENSOR
DESCRIPTION........................270
OPERATION..........................270
TRANSMISSION SOLENOID/TRS ASSEMBLY
DESCRIPTION........................271
OPERATION..........................271
REMOVAL............................272
INSTALLATION........................272
TRANSMISSION TEMPERATURE SENSOR
DESCRIPTION........................272
OPERATION..........................272
VALVE BODY
DESCRIPTION........................273
OPERATION..........................273
REMOVAL............................274
DISASSEMBLY........................275
CLEANING...........................277
INSPECTION.........................277
ASSEMBLY...........................278
INSTALLATION........................279
AUTOMATIC TRANSMISSION -
545RFE
DESCRIPTION
The 545RFE automatic transmission is a sophisti-
cated, multi-range, electronically controlled transmis-
sion which combines optimized gear ratios for
responsive performance, state of the art efficiency
features and low NVH. Other features include driver
adaptive shifting and three planetary gear sets to
provide wide ratio capability with precise ratio steps
for optimum driveability. The three planetary gear
sets also make available a unique alternate second
gear ratio. The primary 2nd gear ratio fits between
1st and 3rd gears for normal through-gear accelera-
tions. The alternate second gear ratio (2prime) allows
smoother 4-2 kickdowns at high speeds to provide
2nd gear passing performance over a wider highway
cruising range. An additional overdrive ratio (0.67:1)
is also provided for greater fuel economy and less
NVH at highway speeds.The hydraulic portion of the transmission consists
of the transmission fluid, fluid passages, hydraulic
valves, and various line pressure control components.
The primary mechanical components of the trans-
mission consist of the following:
²Three multiple disc input clutches
²Three multiple disc holding clutches
²Five hydraulic accumulators
²Three planetary gear sets
²Dual Stage Hydraulic oil pump
²Valve body
²Solenoid pack
The TCM is the ªheartº or ªbrainº of the electronic
control system and relies on information from vari-
ous direct and indirect inputs (sensors, switches, etc.)
to determine driver demand and vehicle operating
conditions. With this information, the TCM can cal-
culate and perform timely and quality shifts through
various output or control devices (solenoid pack,
transmission control relay, etc.).
21 - 178 AUTOMATIC TRANSMISSION - 545RFEWJ

TORQUE CONVERTER LEAK POINTS
Possible sources of converter leaks are:
(1) Leaks at the weld joint around the outside
diameter weld (Fig. 7).
(2) Leaks at the converter hub weld (Fig. 7).
STANDARD PROCEDURE - ALUMINUM
THREAD REPAIR
Damaged or worn threads in the aluminum trans-
mission case and valve body can be repaired by the
use of Heli-CoilsŸ, or equivalent. This repair con-
sists of drilling out the worn-out damaged threads.
Then tap the hole with a special Heli-CoilŸ tap, or
equivalent, and installing a Heli-CoilŸ insert, or
equivalent, into the hole. This brings the hole back to
its original thread size.
Heli-CoilŸ, or equivalent, tools and inserts are
readily available from most automotive parts suppli-
ers.
REMOVAL
CAUTION: The transmission and torque converter
must be removed as an assembly to avoid compo-
nent damage. The converter driveplate, converter
hub o-ring, or oil seal can be damaged if the con-
verter is left attached to the driveplate during
removal. Be sure to remove the transmission and
converter as an assembly.
(1) Disconnect the negative battery cable.
(2) Raise and support the vehicle
(3) Mark propeller shaft and axle yokes for assem-
bly alignment.
(4) Remove the rear propeller shaft
(5) Remove the front propeller shaft.
(6) Remove the engine to transmission collar (Fig.
8).
(7) Remove the exhaust support bracket from the
rear of the transmission.
(8) Disconnect and lower or remove any necessary
exhaust components.
(9) Remove the starter motor.
(10) Rotate crankshaft in clockwise direction until
converter bolts are accessible. Then remove bolts one
at a time. Rotate crankshaft with socket wrench on
dampener bolt.
(11) Disconnect wires from solenoid and pressure
switch assembly, input and output speed sensors, and
line pressure sensor.
Fig. 7 Torque Converter Assembly
1 - TURBINE ASSEMBLY
2-STATOR
3 - CONVERTER HUB
4 - O-RING
5 - IMPELLER ASSEMBLY
6 - CONVERTER CLUTCH PISTON
7 - TURBINE HUB
Fig. 8 Transmission Collar
1 - ENGINE
2 - ENGINE TO TRANSMISSION COLLAR
3 - TRANSMISSION
WJAUTOMATIC TRANSMISSION - 545RFE 21 - 183
AUTOMATIC TRANSMISSION - 545RFE (Continued)

Compressor, Spring - 8251
Installer, Piston - 8252
Installer, Seal - 8253
Installer, Seal - 8254
Installer, Snap-ring - 8255
Stand, Support - 8257
Adapter, Pressure Tap - 8258-A
Adapter, Line Pressure - 8259
21 - 222 AUTOMATIC TRANSMISSION - 545RFEWJ
AUTOMATIC TRANSMISSION - 545RFE (Continued)

Fixture, Input Clutch Pressure - 8260
Plate, Alignment - 8261
End Play Set - 8266
Compressor, Spring - 8285
Installer, Bearing - 8320
Wrench, Filter - 8321
Installer, Piston - 8504
WJAUTOMATIC TRANSMISSION - 545RFE 21 - 223
AUTOMATIC TRANSMISSION - 545RFE (Continued)

4C RETAINER/BULKHEAD
DISASSEMBLY
(1) Remove the 2C piston belleville spring snap-
ring from the 4C retainer /bulkhead (Fig. 53).
(2) Remove the 2C piston Belleville spring from
the retainer/bulkhead (Fig. 53).
(3) Remove the 2C piston from the retainer/bulk-
head. Use 20 psi of air pressure to remove the piston
if necessary.
(4) Remove the 4C clutch snap-ring from the
retainer/bulkhead (Fig. 53).
(5) Remove the 4C clutch pack from the retainer/
bulkhead (Fig. 53).
(6) Using Spring Compressor 8250 and a suitable
shop press, compress the 4C piston return spring and
remove the snap-ring (Fig. 53).(7) Remove the 4C piston return spring and piston
from the retainer/bulkhead (Fig. 53). Use 20 psi of
air pressure to remove the piston if necessary.ASSEMBLY
(1) Clean and inspect all components. Replace any
components which show evidence of excessive wear
or scoring.
(2) Install new seals on the 2C and 4C pistons
(Fig. 53).
(3) Lubricate all seals with MopartATF +4, type
9602 prior to installation.
(4) Install the 4C piston into the 4C retainer/bulk-
head (Fig. 53).
(5) Position the 4C piston return spring onto the
4C piston.
Fig. 53 4C Retainer/Bulkhead Components
1 - SEAL 8 - REACTION PLATE
2 - 2C PISTON 9 - SNAP-RING
3 - PLATE 10 - RETURN SPRING
4 - DISC 11 - SEAL
5 - 2C BELLEVILLE SPRING 12 - 4C PISTON
6 - SNAP-RING 13 - 4C RETAINER/BULKHEAD
7 - SNAP-RING (SELECT)
21 - 224 AUTOMATIC TRANSMISSION - 545RFEWJ

(6) Using Spring Compressor 8250 and a suitable
shop press, compress the 4C piston return spring and
install the snap-ring (Fig. 54).
(7) Assemble and install the 4C clutch pack into
the retainer/bulkhead (Fig. 53) with the steel separa-
tor plate against the piston.
(8) Install the 4C reaction plate and snap-ring into
the retainer/bulkhead (Fig. 53). The 4C reaction plate
is non-directional.
(9) Measure the 4C clutch clearance. The correct
clutch clearance is 0.77-1.39 mm (0.030-0.055 in.).
The snap-ring is selectable. Install the chosen snap-
ring and re-measure to verify the selection.
(10) Install the 2C piston into the retainer/bulk-
head (Fig. 53).
(11) Position the 2C Belleville spring onto the 2C
piston.
(12) Position the 2C Belleville spring snap-ring
onto the 2C Belleville spring (Fig. 53).
(13) Using Spring Compressor 8249 and a suitable
shop press (Fig. 55), compress the belleville spring
until the snap-ring is engaged with the snap-ring
groove in the retainer/bulkhead.
ADAPTER HOUSING SEAL
REMOVAL
(1) Remove the transfer case from the transmis-
sion.
(2) Using a screw mounted on a slide hammer,
remove the adapter housing seal.
INSTALLATION
(1) Clean the adapter seal bore in the adapter
housing of any residue or particles remaining from
the original seal.
(2) Install new oil seal in the adapter housing
using Seal Installer C-3860-A (Fig. 56). A properly
installed seal is flush to the face of the seal bore.
(3) Install the transfer case onto the transmission.
Fig. 54 Compress 4C Piston Return Spring Using
Tool 8250
1 - PRESS
2 - TOOL 8250
Fig. 55 Compress 2C Belleville Spring Using Tool
8249
1 - PRESS
2 - TOOL 8249
Fig. 56 Adapter Housing Seal Installation
1 - TOOL C-3860-A
WJAUTOMATIC TRANSMISSION - 545RFE 21 - 225
4C RETAINER/BULKHEAD (Continued)

HOLDING CLUTCHES
DESCRIPTION
Three hydraulically applied multi-disc clutches are
used to hold some planetary geartrain components
stationary while the input clutches drive others. The
2C, 4C, and Low/Reverse clutches are considered
holding clutches. The 2C and 4C clutches are located
in the 4C retainer/bulkhead (Fig. 66), while the Low/
Reverse clutch is located at the rear of the transmis-
sion case (Fig. 67).
Fig. 66 2C and 4C Clutches
1 - SEAL 8 - REACTION PLATE
2 - 2C PISTON 9 - SNAP-RING
3 - PLATE 10 - RETURN SPRING
4 - DISC 11 - SEAL
5 - 2C BELLEVILLE SPRING 12 - 4C PISTON
6 - SNAP-RING 13 - 4C RETAINER/BULKHEAD
7 - SNAP-RING (SELECT)
WJAUTOMATIC TRANSMISSION - 545RFE 21 - 233

OPERATION
2C CLUTCH
The 2C clutch is hydraulically applied in second
and fifth gear by pressurized fluid against the 2C
piston. When the 2C clutch is applied, the reverse
sun gear assembly is held or grounded to the trans-
mission case by holding the reaction planetary car-
rier.
4C CLUTCH
The 4C clutch is hydraulically applied in second
prime and fourth gear by pressurized fluid againstthe 4C clutch piston. When the 4C clutch is applied,
the reaction annulus gear is held or grounded to the
transmission case.
LOW/REVERSE CLUTCH
The Low/Reverse clutch is hydraulically applied in
park, reverse, neutral, and first gear, only at low
speeds, by pressurized fluid against the Low/Reverse
clutch piston. When the Low/Reverse clutch is
applied, the input annulus assembly is held or
grounded to the transmission case.
Fig. 67 Low/Reverse Clutch
1 - SNAP-RING (SELECT) 8 - SEAL
2 - REACTION PLATE 9 - BELLEVILLE SPRING
3 - DISC 10 - RETAINER
4 - PLATE 11 - SNAP-RING
5 - L/R CLUTCH RETAINER 12 - OVERRUNNING CLUTCH
6 - SEAL 13 - SNAP-RING
7 - PISTON
21 - 234 AUTOMATIC TRANSMISSION - 545RFEWJ
HOLDING CLUTCHES (Continued)

INPUT CLUTCH ASSEMBLY
DESCRIPTION
Three hydraulically applied input clutches are used
to drive planetary components. The underdrive, over-
drive, and reverse clutches are considered input
clutches and are contained within the input clutch
assembly (Fig. 68) and (Fig. 69). The input clutch
assembly also contains:
²Input shaft
²Input hub
²Clutch retainer
²Underdrive piston²Overdrive/reverse piston
²Overdrive hub
²Underdrive hubOPERATION
The three input clutches are responsible for driving
different components of the planetary geartrain.
UNDERDRIVE CLUTCH
The underdrive clutch is hydraulically applied in
first, second, second prime, and third (direct) gears
by pressurized fluid against the underdrive piston.
Fig. 68 Input Clutch Assembly - Part 1
1 - INPUT CLUTCH HUB 11 - UD CLUTCH
2 - O-RING SEALS 12 - PLATE
3 - SEAL 13 - CLUTCH RETAINER
4 - SNAP-RING 14 - SEAL
5 - SNAP-RING 15 - OD/REV PISTON
6 - UD BALANCE PISTON 16 - BELLEVILLE SPRING
7 - SNAP-RING 17 - SNAP-RING
8 - UD PISTON 18 - SEAL RINGS
9 - SPRING 19 - INPUT SHAFT
10 - DISC 20 - LUBRICATION CHECK VALVE AND SNAP-RING
WJAUTOMATIC TRANSMISSION - 545RFE 21 - 235

When the underdrive clutch is applied, the under-
drive hub drives the input sun gear.
OVERDRIVE CLUTCH
The overdrive clutch is hydraulically applied in
third (direct), fourth, and fifth gears by pressurized
fluid against the overdrive/reverse piston. When the
overdrive clutch is applied, the overdrive hub drives
the reverse carrier/input annulus assembly.
REVERSE CLUTCH
The reverse clutch is hydraulically applied in
reverse gear by pressurized fluid against the over-
drive/reverse piston. When the reverse clutch is
applied, the reaction annulus gear is driven.
Fig. 69 Input Clutch Assembly - Part 2
1 - BEARING NUMBER 3 10 - SNAP-RING (SELECT)
2 - OD HUB/SHAFT 11 - PLATE
3 - SNAP-RING (WAVE) 12 - DISC
4 - REV/OD REACTION PLATE 13 - OD CLUTCH
5 - BEARING NUMBER 4 14 - SNAP-RING (TAPERED)
6 - SNAP-RING (FLAT) 15 - UD/OD REACTION PLATE
7 - REVERSE HUB/SHAFT 16 - SNAP-RING (FLAT)
8 - REVERSE CLUTCH 17 - UD HUB/SHAFT
9 - REVERSE REACTION PLATE 18 - BEARING NUMBER 2
21 - 236 AUTOMATIC TRANSMISSION - 545RFEWJ
INPUT CLUTCH ASSEMBLY (Continued)