2002 JEEP GRAND CHEROKEE cli

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)

(12) Secure detent ball and spring with Retainer
Tool 6583 (Fig. 287).
(13) Remove park rod E-clip and separate rod from
manual lever (Fig. 288).
(14) Remove E-clip and washer that retains throt-
tle lever shaft in manual lever (Fig. 289).
(15) Remove manual lever and throttle lever (Fig.
290). Rotate and lift manual lever off valve body and
throttle lever shaft. Then slide throttle lever out of
valve body.
Fig. 283 Solenoid Assembly Screws
1 - OVERDRIVE/CONVERTER CLUTCH SOLENOID ASSEMBLY
2 - HARNESS
Fig. 284 Solenoid Assembly
1 - GOVERNOR SOLENOID WIRES
2 - CONVERTER CLUTCH SOLENOID
3 - SOLENOID SCREWS
4 - GOVERNOR SENSOR WIRES
5 - OVERDRIVE SOLENOID
6 - HARNESS
7 - CASE CONNECTOR
Fig. 285 Boost Valve
1 - BOOST VALVE HOUSING AND COVER
2 - BOOST VALVE TUBE
Fig. 286 Boost Valve Components
1 - SPRING AND VALVE RETAINER
2 - COVER SCREWS
3 - BOOST VALVE COVER
4 - BOOST VALVE PLUG
5 - BOOST VALVE
6 - BOOST VALVE SPRING
21 - 156 AUTOMATIC TRANSMISSION - 42REWJ
VALVE BODY (Continued)

(16) Position pencil magnet next to detent housing
to catch detent ball and spring. Then carefully
remove Retainer Tool 6583 and remove detent ball
and spring (Fig. 291).
(17) Remove screws attaching pressure adjusting
screw bracket to valve body and transfer plate (Fig.
292). Hold bracket firmly against spring tension
while removing last screw.
Fig. 287 Detent Ball And Spring
1 - SPECIAL TOOL 6583 POSITIONED ON DETENT HOUSING
Fig. 288 Park Rod
1 - MANUAL LEVER
2 - E-CLIP
3 - PARK ROD
Fig. 289 Throttle Lever E-Clip And Washer
1 - THROTTLE LEVER SHAFT
2 - E-CLIP AND WASHER
3 - MANUAL SHAFT
Fig. 290 Manual And Throttle Lever
1 - PARK ROD
2 - MANUAL LEVER ASSEMBLY
3 - THROTTLE LEVER
WJAUTOMATIC TRANSMISSION - 42RE 21 - 157
VALVE BODY (Continued)

VALVE BODY UPPER HOUSING
(1) Note location of check balls in valve body upper
housing (Fig. 305). Then remove the one large diam-
eter and the six smaller diameter check balls.
(2) Remove governor plug and shuttle valve covers
(Fig. 307).
(3) Remove E-clip that secures shuttle valve sec-
ondary spring on valve stem (Fig. 306).
(4) Remove throttle plug, primary spring, shuttle
valve, secondary spring, and spring guides (Fig. 307).
(5) Remove boost valve retainer, spring and valve
if not previously removed.
(6) Remove throttle plug and 1-2 and 2-3 governor
plugs (Fig. 294).
(7) Turn upper housing around and remove limit
valve and shift valve covers (Fig. 308).
(8) Remove limit valve housing. Then remove
retainer, spring, limit valve, and 2-3 throttle plug
from limit valve housing (Fig. 308).(9) Remove 1-2 shift control valve and spring (Fig.
308).
(10) Remove 1-2 shift valve and spring (Fig. 308).
(11) Remove 2-3 shift valve and spring from valve
body (Fig. 308).
(12) Remove pressure plug cover (Fig. 308).
(13) Remove line pressure plug, sleeve, throttle
pressure plug and spring (Fig. 308).
Fig. 305 Check Ball Locations In Upper Housing
1 - SMALL DIAMETER CHECK BALLS (6)
2 - LARGE DIAMETER CHECK BALL (1)
Fig. 306 Shuttle Valve E-Clip And Secondary Spring
Location
1 - E-CLIP
2 - SECONDARY SPRING AND GUIDES
3 - SHUTTLE VALVE
21 - 162 AUTOMATIC TRANSMISSION - 42REWJ
VALVE BODY (Continued)

Fig. 307 Shuttle And Boost Valve Components
1 - SPRING 8 - SHUTTLE VALVE COVER
2 - RETAINER 9 - SHUTTLE VALVE
3 - BOOST VALVE 10 - SHUTTLE VALVE PRIMARY SPRING
4 - BOOST VALVE PLUG 11 - GOVERNOR PLUG COVER
5 - SPRING GUIDES 12 - THROTTLE PLUG
6 - E-CLIP 13 - UPPER HOUSING
7 - SHUTTLE VALVE SECONDARY SPRING 14 - BOOST VALVE COVER
WJAUTOMATIC TRANSMISSION - 42RE 21 - 163
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)

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)

UPPER HOUSING VALVE AND PLUG
Refer to (Fig. 318), (Fig. 319) and (Fig. 320) to per-
form the following steps.
(1) Lubricate valves, plugs, springs with clean
transmission fluid.
(2) Assemble regulator valve line pressure plug,
sleeve, throttle plug and spring. Insert assembly in
upper housing and install cover plate. Tighten cover
plate screws to 4 N´m (35 in. lbs.) torque.
(3) Install 1-2 and 2-3 shift valves and springs.
(4) Install 1-2 shift control valve and spring.
(5) Install retainer, spring, limit valve, and 2-3
throttle plug from limit valve housing.
Fig. 318 Shuttle And Boost Valve Components
1 - SPRING 8 - SHUTTLE VALVE COVER
2 - RETAINER 9 - SHUTTLE VALVE
3 - BOOST VALVE 10 - SHUTTLE VALVE PRIMARY SPRING
4 - BOOST VALVE PLUG 11 - GOVERNOR PLUG COVER
5 - SPRING GUIDES 12 - THROTTLE PLUG
6 - E-CLIP 13 - UPPER HOUSING
7 - SHUTTLE VALVE SECONDARY SPRING 14 - BOOST VALVE COVER
Fig. 317 Installing Lower Housing On Transfer Plate
And Upper Housing
1 - VALVE BODY SCREWS (13)
2 - LOWER HOUSING
3 - UPPER HOUSING
4 - TRANSFER PLATE
WJAUTOMATIC TRANSMISSION - 42RE 21 - 169
VALVE BODY (Continued)