2003 JEEP GRAND CHEROKEE service automatic transmission

REAR OUTPUT SHAFT/YOKE/DRIVE CHAIN
Check condition of the seal contact surfaces of the
yoke slinger (Fig. 49). This surface must be clean and
smooth to ensure proper seal life. Replace the yoke
nut and seal washer as neither part should be
reused.
Inspect the shaft threads, sprocket teeth, and bear-
ing surfaces. Minor nicks on the teeth can be
smoothed with an oilstone. Use 320-400 grit emery to
smooth minor scratches on the shaft bearing sur-
faces. Rough threads on the shaft can be chased if
necessary. Replace the shaft if the threads are dam-
aged, bearing surfaces are scored, or if any sprocket
teeth are cracked or broken.
Examine the drive chain and shaft bearings.
Replace the chain and both sprockets if the chain is
stretched, distorted, or if any of the links bind.
Replace the bearings if rough, or noisy.
LOW RANGE ANNULUS GEAR
Inspect annulus gear condition carefully. The gear
is only serviced as part of the front case. If the gear
is damaged, it will be necessary to replace the gear
and front case as an assembly. Do not attempt to
remove the gear (Fig. 50)
FRONT-REAR CASES AND FRONT RETAINER
Inspect the cases and retainer for wear and dam-
age. Clean the sealing surfaces with a scraper and
3M all purpose cleaner. This will ensure proper
sealer adhesion at assembly. Replace the input
retainer seal; do not reuse it.Check case condition. If leaks were a problem, look
for gouges and severe scoring of case sealing sur-
faces. Also make sure the front case mounting studs
are in good condition.
Check the front case mounting studs and vent
tube. The tube can be secured with LoctiteŸ 271 or
680 if loose. The stud threads can be cleaned up with
a die if necessary. Also check condition of the fill/
drain plug threads in the rear case. The threads can
be repaired with a thread chaser or tap if necessary.
Or the threads can be repaired with HelicoilŸ stain-
less steel inserts if required.
OIL PUMP/OIL PICKUP
Examine the oil pump pickup parts. Replace the
pump if any part appears to be worn or damaged. Do
not disassemble the pump as individual parts are not
available. The pump is only available as a complete
assembly. The pickup screen, hose, and tube are the
only serviceable parts and are available separately.
ASSEMBLY
Lubricate transfer case components with automatic
transmission fluid or petroleum jelly (where indi-
cated) during assembly.
CAUTION: The bearing bores in various transfer
case components contain oil feed holes. Make sure
replacement bearings do not block the holes.
Fig. 49 Seal Contact Surface Of Yoke Slinger
1 - FRONT SLINGER (PART OF YOKE)
2 - SEAL CONTACT SURFACE MUST BE CLEAN AND SMOOTH
Fig. 50 Low Range Annulus Gear
1 - FRONT CASE
2 - LOW RANGE ANNULUS GEAR
WJTRANSFER CASE - NV242 21 - 295
TRANSFER CASE - NV242 (Continued)

BLEND DOOR ACTUATOR
DESCRIPTION
The blend door for all models is actuated by an
electric actuator, while the AZC system uses 2 sepa-
rate actuators to allow the driver and passenger to
select individual comfort levels. In the following pro-
cedures, service for both types of actuators is cov-
ered.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
The blend door actuator is used on all models,
whether equipped with manual or Automatic Zone
Control (AZC). This actuator is located on the front of
the HVAC housing to the right of the floor panel
transmission tunnel, and can be removed from the
passenger compartment without instrument panel or
HVAC housing removal.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the glove box door. Refer to Instrument
Panel System for the procedures.
(3) Remove the lower I/P glove box door surround
panel. Refer to Instrument Panel System for the pro-
cedures.
(4) Unplug the wire harness connector from the
blend door actuator (Fig. 17).
(5) Remove the 2 screws that secure the blend
door actuator to the HVAC housing.
(6) Remove the blend door actuator from the
HVAC housing.
INSTALLATION
(1) Install the blend door actuator on the HVAC
housing and tighten the two mounting screws to 2.2
N´m (20 in. lbs.).
(2) Plug in the wire harness connector to the blend
door actuator.
(3) Install the glove box door. Refer to Instrument
Panel System for the procedures.
(4) Install the lower I/P glove box door surround
panel. Refer to Instrument Panel System for the pro-
cedures.
(5) Connect and the battery negative cable.
MODE DOOR ACTUATOR
DESCRIPTION
The mode door actuators for vehicles equipped with
the standard equipment manual temperature control
system are vacuum controlled. The optional Auto-
matic Zone Control (AZC) system uses electric motors
to actuate all mode doors. The service procedures for
both types of actuators are covered by the following
procedures.
Fig. 17 BLEND DOOR ACTUATOR
1 - BLEND DOOR ACTUATOR
2 - ELECTRICAL CONNECTOR
24 - 30 CONTROLSWJ

REMOVAL
REMOVAL - HEAT/DEFROST - PANEL/DEFROST
DOOR ELECTRIC ACTUATOR
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
These actuators are used only on models equipped
with the optional Automatic Zone Control (AZC) sys-
tem.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the two bolts that secure the center
instrument panel support bracket to the left side of
the floor panel transmission tunnel.
(3) Remove the two bolts that secure the center
instrument panel support bracket to the instrument
panel.
(4) Remove the center instrument panel support
bracket from the vehicle.
(5) Unplug the wire harness connector from the
heat/defrost - panel/defrost door actuator (Fig. 18).
(6) Remove the three screws that secure the heat/
defrost-panel/defrost door motor to the HVAC hous-
ing.
(7) Remove the heat/defrost-panel/defrost door
motor from the HVAC housing.
REMOVAL - HEAT/DEFROST DOOR VACUUM
ACTUATOR
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRECAU-
TIONS COULD RESULT IN AN ACCIDENTAL AIRBAG
DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
This actuator is used only on models equipped with
the standard manual temperature control system.
(1) Remove the HVAC housing from the vehicle.
(Refer to 24 - HEATING & AIR CONDITIONING/
DISTRIBUTION/HVAC HOUSING - REMOVAL)
(2) Unplug the vacuum harness connector from the
heat/defrost door vacuum actuator (Fig. 19).
(3) Disengage the heat/defrost door pivot connec-
tion from the heat/defrost door pivot pin.
(4) Remove the screws that secure the heat/defrost
door vacuum actuator to the HVAC housing.
(5) Remove the heat/defrost door vacuum actuator
from the HVAC housing.
Fig. 18 HEAT/DEFROST - PANEL/DEFROST DOOR
ACTUATOR
1 - LEVER ASSEMBLY
2 - LINKAGE
3 - ELECTRIC ACTUATOR
WJCONTROLS 24 - 31
MODE DOOR ACTUATOR (Continued)