1994 JEEP CHEROKEE transmission

SERVICE DIAGNOSIS
21 - 172 AW-4 TRANSMISSION DIAGNOSISJ

AW-4 IN-VEHICLE SERVICE
INDEX
page page
Accumulator Pistons and Springs........... 179
Adapter Housing Seal Replacement.......... 182
Checking Fluid Level and Condition.......... 173
Manual Valve Shaft Seal Replacement....... 178
Park Interlock Cable Adjustment............ 186
Park Rod and Pawl Service................ 181
Park/Neutral Position Switch............... 173
Second Coast Brake Servo................ 181
Shift Cable Adjustment................... 186
Speed Sensor.......................... 182Speed Sensor RotorÐSpeedometer Drive Gear . 183
Throttle Position Sensor (TPS) Service....... 184
Transmission Control Module (TCM) Service . . . 173
Transmission Cooler Line Fittings........... 187
Transmission Cooler Service............... 187
Transmission Throttle Cable Adjustment....... 185
Transmission Throttle Cable Replacement..... 184
Transmission Valve Body Installation......... 177
Transmission Valve Body Removal.......... 176
Transmission Valve Body Solenoids.......... 175
CHECKING FLUID LEVEL AND CONDITION
Recommended fluid for AW-4 transmissions is Mo-
par Dexron IIE/Mercon. Mopar Dexron II may be
used if Mercon fluid is not readily available.
CHECKING FLUID LEVEL
(1) Be sure transmission fluid is at normal operat-
ing temperature. Normal operating temperature is
reached after approximately 15 miles (25 km) of op-
eration.
(2) Position vehicle on level surface. This is impor-
tant for an accurate fluid level check.
(3) Shift transmission through all gear ranges and
back to Park.
(4) Apply parking brakes.
(5) Verify that transmission is in Park.
(6) Wipe off dipstick handle to prevent dirt from
entering fill tube. Then remove dipstick and check
fluid level and condition.
(7) Correct fluid level isto FULL mark on dip-
stick when fluid is at normal operating temper-
ature(Fig. 1).
(8) If fluid level is low, top off level with Mopar
Dexron IIE/Mercon. Mopar Dexron II may also be
used if Mercon is not available.Do not overfill
transmission. Add only enough fluid to bring
level to Full mark.
CHECKING FLUID CONDITION
Inspect the appearance of the fluid during the fluid
level check. The fluid should be clear and free of for-eign material or particles. If the fluid is dark brown
or black in color and smells burnt, the fluid has been
overheated and should be replaced.
Transmission operation should also be checked if
the fluid is severely discolored and contains quanti-
ties of foreign material, metal particles, or clutch disc
friction material.
A small quantity of friction material or metal
particles in the oil pan is normal. The particles
are usually generated during the break-in pe-
riod and indicate normal seating of the various
transmission components.
TRANSMISSION CONTROL MODULE (TCM)
SERVICE
Use the DRB II scan tool to diagnose transmission
control module function whenever a fault is sus-
pected. Replace the module only when actually faulty.
TRANSMISSION CONTROL MODULE
REPLACEMENT
The transmission control module is mounted under
the instrument panel. On left hand drive models, it is
at the driver side of the lower finish panel (Fig. 2).
On right hand drive models, it is at the passenger
side of the lower finish panel (Fig. 3).
To remove the module, disconnect the wire harness,
remove the mounting screws and remove the module
from the finish panel. Tighten the module mounting
screws securely after installation. Also be sure the
wire harness is not twisted, kinked or touching any
body panels.
PARK/NEUTRAL POSITION SWITCH
SWITCH TESTING
Test switch continuity with an ohmmeter. Discon-
nect the switch and check continuity at the connector
terminal positions and in the gear ranges indicated
in Figure 3. Switch continuity should be as follows:Fig. 1 Transmission Fluid Level
JAW-4 IN-VEHICLE SERVICE 21 - 173

²Continuity should exist between terminals B and
C with the transmission in Park and Neutral only
(Fig. 4).
²Continuity should exist between terminals A and E
with the transmission in Reverse (Fig. 4).
²Continuity should exist between terminals A and
G with the transmission in third gear (Fig. 4).
²Continuity should exist between terminals A and
H with the transmission in first and/or second gear
(Fig. 4).
²Continuity should not exist in D position.
PARK/NEUTRAL POSITION SWITCH REMOVAL
(1) Raise vehicle.
(2) Disconnect switch wire harness connector.
(3) Pry washer lock tabs upward and remove
switch attaching nut and tabbed washer (Fig. 5).
(4) Remove switch adjusting bolt (Fig. 5).
(5) Slide switch off manual valve shaft.
PARK/NEUTRAL POSITION SWITCH
INSTALLATION AND ADJUSTMENT
(1) Disconnect shift linkage rod from shift lever on
left side of transmission.
(2) Rotate manual shift lever all the way rearward.
Then rotate lever forward two detent positions to
Neutral.
(3) Install switch on manual valve shaft and in-
stall switch adjusting bolt finger tight. Do not tighten
bolt at this time.(4) Install tabbed washer on manual valve shaft
and install switch attaching nut. Tighten nut to 6.9
Nzm (61 in. lbs.) torque but do not bend washer lock
tabs over nut at this time.
(5) Verify that transmission is in Neutral.
(6) Rotate switch to align neutral standard line
with vertical groove on manual valve shaft (Fig. 6).
(7) Align switch standard line with groove or flat
on manual valve shaft.
Fig. 2 Transmission Control Module Location And
Mounting (Left Hand Drive)
Fig. 3 Transmission Control Module Location And
Mounting (Right Hand Drive)
Fig. 4 Park/Neutral Position Switch Terminals And
Testing
Fig. 5 Park/Neutral Position Switch Removal/
Installation
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(8) Tighten switch adjusting bolt to 13 Nzm(9ft.
lbs.) torque.
(9) Bend at least two washer lock tabs over switch
attaching nut to secure it.
(10) Connect shift linkage rod to shift lever on left
side of case.
(11) Connect switch wires to harness and lower ve-
hicle.
(12) Check switch operation. Engine should start
in Park and Neutral only.
TRANSMISSION VALVE BODY SOLENOIDS
SOLENOID REMOVAL
(1) Remove transmission oil pan drain plug and
drain fluid.
(2) Remove pan bolts and remove oil pan.
(3) Remove oil screen bolts and remove screen (Fig.
7) and gasket. Discard the gasket.(4) Disconnect solenoid wire connector (Fig. 8).
(5) If all solenoids are being removed, mark or tag
wires for assembly reference before disconnecting
them.
(6) Remove bolt attaching solenoids to valve body
and remove solenoids (Fig. 9). Do not allow any valve
body components to fall out when solenoids are re-
moved.
(7) Clean oil filter and pan with solvent and dry
with compressed air.
(8) Remove old sealer material from oil pan and
transmission case.
Solenoid Testing
Test solenoid resistance with an ohmmeter. Con-
nect the ohmmeter leads to the solenoid mounting
bracket and to the solenoid wire terminal (Fig. 10).
Fig. 8 Solenoid Wire Connectors
Fig. 9 Transmission Valve Body Solenoids
Fig. 6 Park/Neutral Position Switch Adjustment
Fig. 7 Oil Screen Removal/Installation
JAW-4 IN-VEHICLE SERVICE 21 - 175

Solenoid resistance should be 11-15 ohms. Replace
the solenoid if resistance is above or below the spec-
ified range.
SOLENOID INSTALLATION
(1) Position solenoids on valve body and install so-
lenoid bolts. Tighten bolts to 10 Nzm (7 ft. lbs.)
torque.
(2) Connect feed wires to solenoids.
(3) Install new gaskets on oil screen and install
screen. Tighten screen bolts to 10 Nzm (7 ft. lbs.)
torque.
(4) Apply bead of Three-Bond TB 1281 or equiva-
lent sealer to oil pan sealing surface. Sealer bead
should be at least 3.0 mm (1/8 in.) wide.
(5) Install oil pan on transmission. Tighten pan
bolts to 7 Nzm (65 in. lbs.) torque.
(6) Install and tighten oil pan drain plug to 20 Nzm
(15 ft. lbs.) torque.
(7) Fill transmission with Mopar Mercon or Dexron
II.
SOLENOID HARNESS ADAPTER SEAL
REPLACEMENT
(1) Remove oil pan and oil screen. Refer to Sole-
noid Removal procedure.
(2) Disconnect solenoid wire connectors (Fig. 8).
(3) Remove bracket securing solenoid harness
adaptor (Fig. 11) to case.
(4) Pull harness adapter and wires out of case.
(5) Remove and discard adapter O-ring.
(6) Lubricate new O-ring and install it on adapter.
(7) Install solenoid wire harness and adapter in
case.
(8) Install adapter bracket and bracket bolt.
(9) Connect wires to solenoids.
(10) Install oil screen and oil pan.
TRANSMISSION VALVE BODY REMOVAL
Removal and installation are the only valve body
service procedures covered in this section. Refer to
the transmission overhaul section for valve body dis-
assembly, cleaning, inspection and reassembly.
(1) Remove oil pan plug and drain transmission
fluid.
(2) Remove oil pan and oil screen. Clean pan and
screen in solvent and dry them with compressed air.
(3) Disconnect solenoid wire connectors (Fig. 8).
Mark wires for assembly reference.
(4) Remove valve body oil tubes (Fig. 12). Carefully
pry tubes out of valve body with screwdriver.
Fig. 11 Harness Adapter Removal/Installation
Fig. 12 Removing Transmission Valve Body Oil
Tubes
Fig. 10 Testing Transmission Valve Body Solenoid
21 - 176 AW-4 IN-VEHICLE SERVICEJ

(5) Disconnect throttle cable from throttle cam
(Fig. 13).
(6) Remove valve body bolts. Bolt locations are out-
lined in Figure 14.
(7) Lower valve body and remove overdrive clutch
accumulator springs, direct clutch accumulator
springs and second brake accumulator spring (Fig.
15)
(8) Remove valve body and check ball and spring
(Fig. 16).
TRANSMISSION VALVE BODY INSTALLATION
(1) Connect cable to throttle cam (Fig. 13).
(2) Install check ball and spring (Fig. 16).
(3) Position accumulator springs and spacers on
valve body.(4) Align valve body manual valve with shift sector
(Fig. 17) and carefully position valve body on case.
(5) Install valve body bolts (Fig. 14). Tighten bolts
evenly to 10 Nzm (7 ft. lbs.) torque.
(6) Install valve body oil tubes. Be sure tube ends
(L) and (M) are installed as shown in Figure 18.
(7) Remove old sealer material from oil pan and
transmission case.
(8) Clean oil screen and oil pan with solvent (if not
done previously). Dry both components with com-
pressed air only. Do not use shop towels.
(9) Install new gaskets on oil screen and install
screen on case. Tighten screen attaching bolts to 10
Nzm (7 ft. lbs.) torque.
Fig. 13 Removing/Installing Throttle Cable
Fig. 14 Transmission Valve Body Bolt Locations
Fig. 15 Accumulator Springs
Fig. 16 Removing/Installing Check Ball And Spring
JAW-4 IN-VEHICLE SERVICE 21 - 177

(10) Apply bead of Mopar or Loctite 599 sealer to
sealing surface of oil pan. Sealer bead should be at
least 3 mm (1/8 in.) wide. Then install oil pan and
tighten pan bolts to 7.4 Nzm (65 in. lbs.) torque.
(11) Install new gasket on oil pan drain plug and
install plug in pan. Tighten plug to 20 Nzm (15 ft.
lbs.) torque.
(12) Fill transmission with Mopar MerconŸ fluid.
MANUAL VALVE SHAFT SEAL REPLACEMENT
(1) Remove park/neutral position switch and dis-
connect transmission shift lever.
(2) Remove oil pan and valve body.(3) Remove bolts attaching park rod bracket to
case (Fig. 20).
(4) Remove park rod from shift sector (Fig. 21).
(5) Cut spacer sleeve with chisel and remove it
from manual valve shaft (Fig. 22).
(6) Remove pin from shaft and sector with pin
punch.
(7) Remove shaft and sector from case.
(8) Pry shaft seals out of case (Fig. 23).
(9) Inspect the manual valve shaft and sector. Re-
place either component if worn or damaged.
Fig. 19 Manual Valve Shaft And Seals
Fig. 20 Removing/Installing Park Rod Bracket
Fig. 17 Shift Sector And Manual Valve Alignment
Fig. 18 Installing Transmission Valve Body Oil
Tubes
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(2) Remove accumulator pistons with compressed
air (Fig. 27). Apply air through small feed hole next
to each piston bore. Catch each piston in a shop
towel as it exits bore.
CAUTION: Use only enough air pressure to ease
each piston out of the bore. In addition, remove the
pistons one at a time and tag the pistons and
springs for assembly reference. Do not intermix
them.
(3) Remove and discard piston O-ring seals. Then
clean pistons and springs with solvent.(4) Inspect pistons, springs and piston bores. Re-
place worn damaged pistons. Replace broken, col-
lapsed or distorted springs. Replace case if piston
bores are damaged.
(5) If small cushion spring in any piston must be
replaced, remove spring retainer clip and remove
spring from piston (Fig. 28). A small hooked tool or
small thin blade screwdriver can be used to remove
clip. A thin wall, deep socket, or pin punch can be
used to reseat clip after spring replacement.
(6) Install new O-ring seals on pistons. Lubricate
seals and pistons and piston bores with transmission
fluid.
(7) Install pistons and springs (Fig. 29).
(8) Install valve body, oil screen and oil pan. Use
Mopar or Loctite 599 on oil pan sealing surface.
Fig. 25 Installing Spacer Sleeve On Sector
Fig. 26 Installing Park Rod Bracket
Fig. 27 Accumulator Piston Removal
Fig. 28 Small Cushion Spring Retention
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