2002 JEEP GRAND CHEROKEE clutch

3-4 SHIFT VALVE
The PCM energizes the overdrive solenoid during
the 3-4 upshift (Fig. 271). This causes the solenoid
check ball to close the vent port allowing line pres-
sure from the 2-3 shift valve to act directly on the 3-4
upshift valve. Line pressure on the 3-4 shift valve
overcomes valve spring pressure moving the valve to
the upshift position (Fig. 272). This action exposes
the feed passages to the 3-4 timing valve, 3-4 quick
fill valve, 3-4 accumulator, and ultimately to the
overdrive piston.
3-4 TIMING VALVE
The 3-4 timing valve is moved by line pressure
coming through the 3-4 shift valve (Fig. 272). After
the shift, the timing valve holds the 2-3 shift valve in
an upshift position. The purpose is to prevent the 2-3
valve from downshifting before the 3-4 valve (Fig.
271).
3-4 QUICK FILL VALVE
The 3-4 quick fill valve provides faster engagement
of the overdrive clutch during 3-4 upshifts. The valve
temporarily bypasses the clutch piston feed orifice at
the start of a 3-4 upshift (Fig. 271). This exposes a
larger passage into the piston retainer resulting in a
much faster clutch fill and apply sequence. The quick
fill valve does not bypass the regular clutch feed ori-
fice throughout the 3-4 upshift. Instead, once a pre-
determined pressure develops within the clutch, the
valve closes the bypass (Fig. 272). Clutch fill is then
completed through the regular feed orifice.
Fig. 271 3-4 Shift Valve Before Shift
Fig. 272 3-4 Shift Valve After Shift
WJAUTOMATIC TRANSMISSION - 42RE 21 - 149
VALVE BODY (Continued)

MANUAL VALVE
The manual valve (Fig. 276) is a relay valve. The
purpose of the manual valve is to direct fluid to the
correct circuit needed for a specific gear or driving
range. The manual valve, as the name implies, is
manually operated by the driver with a lever located
on the side of the valve body. The valve is connected
mechanically by either a cable or linkage to the gear-
shift mechanism. The valve is held in each of its
positions by a spring-loaded roller or ball that
engages the ªroostercombº of the manual valve lever.
CONVERTER CLUTCH LOCK-UP VALVE
The torque converter clutch (TCC) lock-up valve
controls the back (ON) side of the torque converter
clutch. When the PCM energizes the TCC solenoid to
engage the converter clutch piston, pressure is
applied to the TCC lock-up valve which moves to the
right and applies pressure to the torque converter
clutch.
CONVERTER CLUTCH LOCK-UP TIMING VALVE
The torque converter clutch (TCC) lock-up timing
valve is there to block any 4-3 downshift until the
TCC is completely unlocked and the clutch is disen-
gaged.
SHUTTLE VALVE
The assembly is contained in a bore in the valve
body above the shift valves. When the manual valve
is positioned in the Drive range, throttle pressure
acts on the throttle plug of the shuttle valve (Fig.
268) to move it against a spring, increasing the
spring force on the shuttle valve. During a part or
full throttle 1-2 upshift, the throttle plug is bottomed
by throttle pressure, holding the shuttle valve to the
right against governor pressure, and opening a
by±pass circuit. The shuttle valve controls the qual-
ity of the kickdown shift by restricting the rate of
fluid discharge from the front clutch and servo
release circuits. During a 3-2 kickdown, fluid dis-
charges through the shuttle by-pass circuit. When
the shuttle valve closes the by-pass circuit, fluid dis-
charge is restricted and controlled for the application
of the front band. During a 2-3 ªlift footº upshift, the
shuttle valve by-passes the restriction to allow full
fluid flow through the by-pass groove for a faster
release of the band.
Fig. 276 Manual Valve
WJAUTOMATIC TRANSMISSION - 42RE 21 - 153
VALVE BODY (Continued)

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)

(18) Remove adjusting screw bracket, line pressure
adjusting screw, pressure regulator valve spring and
switch valve spring (Fig. 293). Do not remove throttle
pressure adjusting screw from bracket and do not
disturb setting of either adjusting screw during
removal.
(19) Turn upper housing over and remove switch
valve, regulator valve and spring, and manual valve
(Fig. 294).
(20) Remove kickdown detent, kickdown valve, and
throttle valve and spring (Fig. 294).
(21) Loosen left-side 3-4 accumulator housing
attaching screw about 2-3 threads. Then remove cen-
ter and right-side housing attaching screws (Fig.
295).
(22) Carefully rotate 3-4 accumulator housing
upward and remove 3-4 shift valve spring and con-
verter clutch valve plug and spring (Fig. 296).
(23) Remove left-side screw and remove 3-4 accu-
mulator housing from valve body (Fig. 297).
(24) Bend back tabs on boost valve tube brace (Fig.
298).
Fig. 291 Detent Ball And Spring
1 - DETENT HOUSING
2 - DETENT SPRING
3 - DETENT BALL
4 - PENCIL MAGNET
Fig. 292 Adjusting Screw Bracket Fastener
1 - T25 TORXŸ BIT
2 - REMOVE THESE SCREWS FIRST
3 - BRACKET
4 - BRACKET
5 - REMOVE THIS SCREW LAST
Fig. 293 Adjusting Screw Bracket And Spring
1 - SWITCH VALVE SPRING
2 - LINE PRESSURE SCREW
3 - THROTTLE PRESSURE ADJUSTING SCREW
4 - ADJUSTING SCREW BRACKET
5 - PRESSURE REGULATOR VALVE SPRING
21 - 158 AUTOMATIC TRANSMISSION - 42REWJ
VALVE BODY (Continued)

Fig. 294 Upper Housing Control Valve Locations
1 - UPPER HOUSING 8 - MANUAL VALVE
2 - REGULATOR VALVE 9 - 1-2 GOVERNOR PLUG
3 - SWITCH VALVE 10 - GOVERNOR PLUG COVER
4 - REGULATOR VALVE SPRING 11 - THROTTLE PLUG
5 - KICKDOWN VALVE 12 - 2-3 GOVERNOR PLUG
6 - KICKDOWN DETENT 13 - SHUTTLE VALVE PRIMARY SPRING
7 - THROTTLE VALVE AND SPRING
Fig. 295 Accumulator Housing Screw Locations
1 - LOOSEN THIS SCREW
2 - REMOVE THESE SCREWS
3 - 3-4 ACCUMULATOR HOUSINGFig. 296 3-4 Shift And Converter Clutch Valve
Springs And Plug
1 - ACCUMULATOR HOUSING
2 - CONVERTER CLUTCH VALVE SPRING
3 - CLUTCH VALVE PLUG
4 - 3-4 SHIFT VALVE SPRING
WJAUTOMATIC TRANSMISSION - 42RE 21 - 159
VALVE BODY (Continued)

(25) Remove boost valve connecting tube (Fig.
299). Disengage tube from upper housing port first.
Then rock opposite end of tube back and forth to
work it out of lower housing.
CAUTION: Do not use tools to loosen or pry the
connecting tube out of the valve body housings.
Loosen and remove the tube by hand only.
(26) Turn valve body over so lower housing is fac-
ing upward (Fig. 300). In this position, the two check
balls in upper housing will remain in place and not
fall out when lower housing and separator plate are
removed.
(27) Remove screws attaching valve body lower
housing to upper housing and transfer plate (Fig.300). Note position of boost valve tube brace for
assembly reference.
(28) Remove lower housing and overdrive separa-
tor plate from transfer plate (Fig. 300).
(29) Remove the ECE check ball from the transfer
plate (Fig. 301). The ECE check ball is approximately
4.8 mm (3/16 in.) in diameter.
(30) Remove transfer plate from upper housing
(Fig. 302).
(31) Turn transfer plate over so upper housing sep-
arator plate is facing upward.
(32) Remove upper housing separator plate from
transfer plate (Fig. 303). Note position of filter in
separator plate for assembly reference.
(33) Remove rear clutch and rear servo check balls
from transfer plate. Note check ball location for
assembly reference (Fig. 304).
Fig. 297 Accumulator Housing, Valve Springs And
Plug
1 - 3-4 SHIFT VALVE SPRING
2 - CONVERTER CLUTCH VALVE SPRING AND PLUG
3 - 3-4 ACCUMULATOR HOUSING
Fig. 298 Boost Valve Tube Brace
1 - BOOST VALVE TUBE
2 - TUBE BRACE (DOUBLE TAB)
Fig. 299 Boost Valve Tube
1 - BOOST VALVE TUBE
2 - LOWER HOUSING
3 - DISENGAGE THIS END OF TUBE FIRST
4 - UPPER HOUSING
Fig. 300 Lower Housing
1 - LOWER HOUSING
2 - OVERDRIVE SEPARATOR PLATE
3 - TRANSFER PLATE AND UPPER HOUSING
21 - 160 AUTOMATIC TRANSMISSION - 42REWJ
VALVE BODY (Continued)

Fig. 301 ECE Check Ball
1 - ECE CHECK BALL (3/169)
Fig. 302 Transfer Plate
1 - UPPER HOUSING
2 - TRANSFER PLATE
Fig. 303 Upper Housing Separator Plate
1 - TRANSFER PLATE
2 - UPPER HOUSING SEPARATOR PLATE
3 - FILTER SCREEN
4 - BRACE
Fig. 304 Rear Clutch And Rear Servo Check Ball
1 - REAR CLUTCH CHECK BALL
2 - REAR SERVO CHECK BALL
3 - TRANSFER PLATE
WJAUTOMATIC TRANSMISSION - 42RE 21 - 161
VALVE BODY (Continued)