2003 JEEP GRAND CHEROKEE piston ring

BOOST VALVE
The boost valve (Fig. 277) provides increased fluid
apply pressure to the overdrive clutch during 3-4
upshifts (Fig. 278), and when accelerating in fourth
gear. The boost valve also serves to increase line
pressure during torque converter lock-up.
REMOVAL
The valve body can be removed for service without
having to remove the transmission assembly.
The valve body can be disassembled for cleaning
and inspection of the individual components.
The only replaceable valve body components are:
²Manual lever.
²Manual lever washer, seal, E-clip, and shaft
seal.
²Manual lever detent ball.
²Throttle lever.
²Fluid filter.
²Pressure adjusting screw bracket.
²Governor pressure solenoid.
²Governor pressure sensor (includes transmission
temperature thermistor).
²Converter clutch/overdrive solenoid assembly
and harness.
²Governor housing gasket.
²Solenoid case connector O-rings.
(1) Shift transmission into NEUTRAL.
(2) Raise vehicle.
(3) Remove gearshift and throttle levers from shaft
of valve body manual lever.
(4) Disconnect wires at solenoid case connector
(Fig. 279).
(5) Position drain pan under transmission oil pan.
(6) Remove transmission oil pan and gasket.
(7) Remove fluid filter from valve body.
(8) Remove bolts attaching valve body to transmis-
sion case.
(9) Lower valve body enough to remove accumula-
tor piston and springs.
(10) Work manual lever shaft and electrical con-
nector out of transmission case.
(11) Lower valve body, rotate valve body away
from case, pull park rod out of sprag, and remove
valve body (Fig. 280).
Fig. 277 Boost Valve Before Lock-up
Fig. 278 Boost Valve After Lock-up
Fig. 279 Transmission Case Connector
1 - SOLENOID CASE CONNECTOR
2 - PARK/NEUTRAL POSITION SWITCH
21 - 154 AUTOMATIC TRANSMISSION - 42REWJ
VALVE BODY (Continued)

VALVE BODY LOWER HOUSING
(1) Remove timing valve cover.
(2) Remove 3-4 timing valve and spring.
(3) Remove 3-4 quick fill valve, spring and plug.
(4) Remove 3-4 shift valve and spring.
(5) Remove converter clutch valve, spring and plug
(Fig. 309).
(6) Remove converter clutch timing valve, retainer
and valve spring.
3-4 ACCUMULATOR HOUSING
(1) Remove end plate from housing.
(2) Remove piston spring.
(3) Remove piston. Remove and discard piston
seals (Fig. 310).
CLEANING
Clean the valve housings, valves, plugs, springs,
and separator plates with a standard parts cleaning
solution only. Do not use gasoline, kerosene, or any
type of caustic solution.
Do not immerse any of the electrical components in
cleaning solution. Clean the governor solenoid and
sensor and the dual solenoid and harness assembly
by wiping them off with dry shop towels only.
Dry all except the electrical parts with compressed
air. Make sure all passages are clean and free from
obstructions.Do not use rags or shop towels to
dry or wipe off valve body components. Lint
from these materials can stick to valve body
parts, interfere with valve operation, and clog
filters and fluid passages.
Fig. 309 Lower Housing Shift Valves and Springs
1 - 3-4 ACCUMULATOR HOUSING 11 - TIMING VALVE COVER
2 - 3-4 SHIFT VALVE AND SPRING 12 - PLUG
3 - PLUG 13 - 3-4 TIMING VALVE AND SPRING
4 - SPRING RETAINER 14 - LOWER HOUSING
5 - CONVERTER CLUTCH VALVE AND SPRING 15 - ACCUMULATOR END PLATE
6 - CONVERTER CLUTCH TIMING VALVE AND SPRING 16 - 3-4 ACCUMULATOR PISTON AND SPRING
7 - OVERDRIVE SEPARATOR PLATE 17 - E-CLIP
8 - CASE CONNECTOR 18 - 3-4 QUICK FILL SPRING AND VALVE
9 - CONVERTER CLUTCH SOLENOID 19 - SOLENOID GASKET
10 - OVERDRIVE SOLENOID 20 - HARNESS
WJAUTOMATIC TRANSMISSION - 42RE 21 - 165
VALVE BODY (Continued)

Wipe the governor pressure sensor and solenoid
valve with dry, lint free shop towels only. The O-rings
on the sensor and solenoid valve are the only service-
able components. Be sure the vent ports in the sole-
noid valve are open and not blocked by dirt or debris.
Replace the valve and/or sensor only when DRB scan
tool diagnosis indicates this is necessary. Or, if either
part has sustained physical damage (dented,
deformed, broken, etc.).
CAUTION: Do not turn the small screw at the end of
the solenoid valve for any reason. Turning the
screw in either direction will ruin solenoid calibra-
tion and result in solenoid failure. In addition, the
filter on the solenoid valve is NOT serviceable. Do
not try to remove the filter as this will damage the
valve housing.
INSPECTION
Inspect the throttle and manual valve levers and
shafts. Do not attempt to straighten a bent shaft or
correct a loose lever. Replace these components if
worn, bent, loose or damaged in any way.
Inspect all of the valve body mating surfaces for
scratches, nicks, burrs, or distortion. Use a straight-
edge to check surface flatness. Minor scratches may
be removed with crocus cloth using only very light
pressure.Minor distortion of a valve body mating surface
may be corrected by smoothing the surface with a
sheet of crocus cloth. Position the crocus cloth on a
surface plate, sheet of plate glass or equally flat sur-
face. If distortion is severe or any surfaces are
heavily scored, the valve body will have to be
replaced.
CAUTION: Many of the valves and plugs, such as
the throttle valve, shuttle valve plug, 1-2 shift valve
and 1-2 governor plug, are made of coated alumi-
num. Aluminum components are identified by the
dark color of the special coating applied to the sur-
face (or by testing with a magnet). Do not sand alu-
minum valves or plugs under any circumstances.
This practice could damage the special coating
causing the valves/plugs to stick and bind.
Inspect the valves and plugs for scratches, burrs,
nicks, or scores. Minor surface scratches on steel
valves and plugs can be removed with crocus cloth
butdo not round off the edges of the valve or
plug lands.Maintaining sharpness of these edges is
vitally important. The edges prevent foreign matter
from lodging between the valves and plugs and the
bore.
Inspect all the valve and plug bores in the valve
body. Use a penlight to view the bore interiors.
Replace the valve body if any bores are distorted or
scored. Inspect all of the valve body springs. The
springs must be free of distortion, warpage or broken
coils.
Check the two separator plates for distortion or
damage of any kind. Inspect the upper housing,
lower housing, 3-4 accumulator housing, and transfer
plate carefully. Be sure all fluid passages are clean
and clear. Check condition of the upper housing and
transfer plate check balls as well. The check balls
and ball seats must not be worn or damaged.
Trial fit each valve and plug in its bore to check
freedom of operation. When clean and dry, the valves
and plugs should drop freely into the bores.
Valve body bores do not change dimensionally with
use. If the valve body functioned correctly when new,
it will continue to operate properly after cleaning and
inspection. It should not be necessary to replace a
valve body assembly unless it is damaged in han-
dling.
The only serviceable valve body components are
listed below. The remaining valve body components
are serviced only as part of a complete valve body
assembly. Serviceable parts are:
²dual solenoid and harness assembly
²solenoid gasket
²solenoid case connector O-rings and shoulder
bolt
²switch valve and spring
Fig. 310 Accumulator Housing Components
1 - ACCUMULATOR PISTON
2 - 3-4 ACCUMULATOR HOUSING
3 - TEFLON SEALS
4 - PISTON SPRING
5 - COVER PLATE AND SCREWS
21 - 166 AUTOMATIC TRANSMISSION - 42REWJ
VALVE BODY (Continued)

²pressure adjusting screw and bracket assembly
²throttle lever
²manual lever and shaft seal
²throttle lever shaft seal, washer, and E-clip
²fluid filter and screws
²detent ball and spring
²valve body screws
²governor pressure solenoid
²governor pressure sensor and retaining clip
²park lock rod and E-clip
ASSEMBLY
CAUTION: Do not force valves or plugs into place
during reassembly. If the valve body bores, valves
and plugs are free of distortion or burrs, the valve
body components should all slide into place easily.
In addition, do not overtighten the transfer plate
and valve body screws during reassembly. Over-
tightening can distort the housings resulting in
valve sticking, cross leakage and unsatisfactory
operation. Tighten valve body screws to recom-
mended torque only.
LOWER HOUSING
(1) Lubricate valves, springs, and the housing
valve and plug bores with clean transmission fluid
(Fig. 309).
(2) Install 3-4 timing valve spring and valve in
lower housing.
(3) Install 3-4 quick fill valve in lower housing.
(4) Install 3-4 quick fill valve spring and plug in
housing.
(5) Install timing valve end plate. Tighten end
plate screws to 4 N´m (35 in. lbs.) torque.
3-4 ACCUMULATOR
(1) Lubricate accumulator piston, seals and hous-
ing piston bore with clean transmission fluid (Fig.
310).
(2) Install new seal rings on accumulator piston.
(3) Install piston and spring in housing.
(4) Install end plate on housing.
TRANSFER PLATE
(1) Install rear clutch and rear servo check balls in
transfer plate (Fig. 311).
(2) Install filter screen in upper housing separator
plate (Fig. 312).
(3) Align and position upper housing separator
plate on transfer plate (Fig. 313).
(4) Install brace plate (Fig. 313). Tighten brace
attaching screws to 4 N´m (35 in. lbs.) torque.
(5) Install remaining separator plate attaching
screws. Tighten screws to 4 N´m (35 in. lbs.) torque.
UPPER AND LOWER HOUSING
(1) Position upper housing so internal passages
and check ball seats are facing upward. Then install
check balls in housing (Fig. 314). Eight check balls
are used. The single large check ball is approxi-
mately 8.7 mm (11/32 in.) diameter. The single small
check ball is approximately 4.8 mm (3/16 in.) in
diameter. The remaining 6 check balls are approxi-
mately 6.3 mm (1/4 in.) in diameter.
(2) Position assembled transfer plate and upper
housing separator plate on upper housing (Fig. 315).
Be sure filter screen is seated in proper housing
recess.
Fig. 311 Rear Clutch And Rear Servo Check Ball
Locations
1 - REAR CLUTCH CHECK BALL
2 - REAR SERVO CHECK BALL
3 - TRANSFER PLATE
Fig. 312 Separator Plate Filter Screen Installation
1 - UPPER HOUSING SEPARATOR PLATE
2 - FILTER SCREEN
WJAUTOMATIC TRANSMISSION - 42RE 21 - 167
VALVE BODY (Continued)

GOVERNOR BODY, SENSOR AND SOLENOID
(1) Turn valve body assembly over so accumulator
side of transfer plate is facing down.
(2) Install new O-rings on governor pressure sole-
noid and sensor.
(3) Lubricate solenoid and sensor O-rings with
clean transmission fluid.
(4) Install governor pressure sensor in governor
body.
(5) Install governor pressure solenoid in governor
body. Push solenoid in until it snaps into place in
body.
(6) Position governor body gasket on transfer
plate.
(7) Install retainer plate on governor body and
around solenoid. Be sure solenoid connector is posi-
tioned in retainer cutout.
(8) Align screw holes in governor body and trans-
fer plate. Then install and tighten governor body
screws to 4 N´m (35 in. lbs.) torque.
(9) Connect harness wires to governor pressure
solenoid and governor pressure sensor.
(10) Install fluid filter and pan.
(11) Lower vehicle.
(12) Fill transmission with recommended fluid and
road test vehicle to verify repair.
INSTALLATION
(1) Check condition of O-ring seals on valve body
harness connector (Fig. 330). Replace seals on con-
nector body if cut or worn.
(2) Check condition of manual lever shaft seal in
transmission case. Replace seal if lip is cut or worn.
Install new seal with 15/16 deep well socket (Fig.
331).
(3) Check condition of seals on accumulator piston
(Fig. 332). Install new piston seals, if necessary.
(4) Place valve body manual lever in low (1 posi-
tion) so ball on park lock rod will be easier to install
in sprag.
(5) Lubricate shaft of manual lever with petroleum
jelly. This will ease inserting shaft through seal in
case.
(6) Lubricate seal rings on valve body harness con-
nector with petroleum jelly.
(7) Position valve body in case and work end of
park lock rod into and through pawl sprag. Turn pro-
peller shaft to align sprag and park lock teeth if nec-
essary. The rod will click as it enters pawl. Move rod
to check engagement.
CAUTION: It is possible for the park rod to displace
into a cavity just above the pawl sprag during
installation. Make sure the rod is actually engaged
in the pawl and has not displaced into this cavity.(8) Install accumulator springs and piston into
case. Then swing valve body over piston and outer
spring to hold it in place.
(9) Align accumulator piston and outer spring,
manual lever shaft and electrical connector in case.
(10) Then seat valve body in case and install one
or two bolts to hold valve body in place.
(11) Tighten valve body bolts alternately and
evenly to 11 N´m (100 in. lbs.) torque.
(12) Install new fluid filter on valve body. Tighten
filter screws to 4 N´m (35 in. lbs.) torque.
(13) Install throttle and gearshift levers on valve
body manual lever shaft.
(14) Check and adjust front and rear bands if nec-
essary.
(15) Connect solenoid case connector wires.
(16) Install oil pan and new gasket. Tighten pan
bolts to 13.6 N´m (125 in. lbs.) torque.
(17) Lower vehicle and fill transmission with
MopartATF +4, type 9602, fluid.
(18) Check and adjust gearshift and throttle valve
cables, if necessary.
ADJUSTMENTS - VALVE BODY
CONTROL PRESSURE ADJUSTMENTS
There are two control pressure adjustments on the
valve body;
²Line Pressure
²Throttle Pressure
Line and throttle pressures are interdependent
because each affects shift quality and timing. As a
result, both adjustments must be performed properly
and in the correct sequence. Adjust line pressure first
and throttle pressure last.
Fig. 330 Valve Body Harness Connector O-Ring Seal
1 - CONNECTOR O-RINGS
2 - VALVE BODY HARNESS CONNECTOR
3 - HARNESS
WJAUTOMATIC TRANSMISSION - 42RE 21 - 175
VALVE BODY (Continued)

LINE PRESSURE ADJUSTMENT
Measure distance from the valve body to the inner
edge of the adjusting screw with an accurate steel
scale (Fig. 333).
Distance should be 33.4 mm (1-5/16 in.).
If adjustment is required, turn the adjusting screw
in, or out, to obtain required distance setting.
NOTE: The 33.4 mm (1-5/16 in.) setting is an
approximate setting. Manufacturing tolerances may
make it necessary to vary from this dimension to
obtain desired pressure.
One complete turn of the adjusting screw changes
line pressure approximately 1-2/3 psi (9 kPa).
Turning the adjusting screw counterclockwise
increases pressure while turning the screw clockwise
decreases pressure.THROTTLE PRESSURE ADJUSTMENT
Insert Gauge Tool C-3763 between the throttle
lever cam and the kickdown valve stem (Fig. 334).
Push the gauge tool inward to compress the kick-
down valve against the spring and bottom the throt-
tle valve.
Maintain pressure against kickdown valve spring.
Turn throttle lever stop screw until the screw head
touches throttle lever tang and the throttle lever cam
touches gauge tool.
NOTE: The kickdown valve spring must be fully
compressed and the kickdown valve completely
bottomed to obtain correct adjustment.
Fig. 331 Manual Lever Shaft Seal
1 - 15/1688SOCKET
2 - SEAL
Fig. 332 Accumulator Piston Components
1 - INNER SPRING
2 - ACCUMULATOR PISTON
3 - OUTER SPRING
4 - SEAL RINGS
Fig. 333 Line Pressure Adjustment
1 - WRENCH
2 - 1±5/16 INCH
Fig. 334 Throttle Pressure Adjustment
1 - HEX WRENCH (IN THROTTLE LEVER ADJUSTING SCREW)
2 - SPECIAL TOOL C-3763 (POSITIONED BETWEEN THROTTLE
LEVER AND KICKDOWN VALVE)
21 - 176 AUTOMATIC TRANSMISSION - 42REWJ
VALVE BODY (Continued)

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)