2003 JEEP GRAND CHEROKEE ACCESSORY DRIVE DRIVE BELTS

(12) Install the push rods, rocker arms, pivots and
bridges in the order they were removed (Refer to 9 -
ENGINE/CYLINDER HEAD/ROCKER ARM /
ADJUSTER ASSY - INSTALLATION).
(13) Install the engine cylinder head cover (Refer
to 9 - ENGINE/CYLINDER HEAD/CYLINDER
HEAD COVER(S) - INSTALLATION).
(14) Attach the air conditioner compressor mount-
ing bracket to the engine cylinder head and block.
Tighten the bolts to 40 N´m (30 ft. lbs.) torque.
(15) Attach the air conditioning compressor to the
bracket. Tighten the bolts to 27 N´m (20 ft. lbs.)
torque.
CAUTION: The serpentine drive belt must be routed
correctly. Incorrect routing can cause the water
pump to turn in the opposite direction causing the
engine to overheat.
(16) Install the serpentine drive belt. (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(17) Install the air cleaner and ducting.
(18) Connect the hoses to the engine thermostat
housing and fill the cooling system to the specified
level (Refer to 7 - COOLING - STANDARD PROCE-
DURE).
(19) The automatic transmission throttle linkage
and cable must be adjusted after completing the
engine cylinder head installation (Refer to 21 -
TRANSMISSION/TRANSAXLE/AUTOMATIC - AW4/
THROTTLE VALVE CABLE - ADJUSTMENTS).
(20) Install the temperature sending unit and con-
nect the wire connector.
(21) If equipped with air conditioning, install A/C
compressor (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING/A/C COMPRESSOR -
INSTALLATION) and charge A/C system (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE).
(22) Connect negative cable to battery.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN DIRECT
LINE WITH THE FAN. DO NOT PUT HANDS NEAR
THE PULLEYS, BELTS OR FAN. DO NOT WEAR
LOOSE CLOTHING.
(23) Operate the engine with the radiator cap off.
Inspect for leaks and continue operating the engine
until the engine thermostat opens. Add coolant, if
required.CYLINDER HEAD COVER(S)
DESCRIPTION
The cylinder head cover (Fig. 11) is made of
stamped steel and incorporates the Crankcase Venti-
lation (CCV) Hoses and the oil fill opening.
REMOVAL
The cylinder head cover is isolated from the cylin-
der head via grommets and a reusable molded rubber
gasket. The grommet and limiter are retained in the
cylinder head cover.
(1) Disconnect negative cable from battery.
(2) Disconnect the Crankcase Ventilation (CCV)
vacuum hose from engine cylinder head cover.
(3) Disconnect the fresh air inlet hose from the
engine cylinder head cover.
(4) Disconnect the accelerator, transmission, and
speed (if equipped) control cables from the throttle
body (Fig. 12).
(5) Remove the three bolts that fasten the control
cable bracket to the intake manifold.
(6) Remove control cables from cylinder head cover
clip.
(7) Position control cables and bracket away from
cylinder head cover secure with tie straps.
(8) Remove the engine cylinder head cover mount-
ing bolts.
(9) Remove the engine cylinder head cover and
gasket.
Fig. 11 Cylinder Head Cover
9 - 22 ENGINE - 4.0LWJ
CYLINDER HEAD (Continued)

(16) Install the serpentine drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
NOTE: During installation, lubricate the hydraulic
valve tappets and all valve components with
MoparTEngine Oil Supplement, or equivalent. TheMoparTEngine Oil Supplement, or equivalent must
remain with the engine oil for at least 1609 km
(1,000 miles). The oil supplement need not be
drained until the next scheduled oil change.
(17) Install the radiator (Refer to 7 - COOLING/
ENGINE/RADIATOR - INSTALLATION).
(18) Check the ignition timing and adjust as nec-
essary.
(19) Install the grille and bumper, if removed.
(20) Connect negative cable to battery.
CONNECTING ROD BEARINGS
STANDARD PROCEDURE - FITTING
CONNECTING ROD BEARINGS
Inspect the connecting rod bearings for scoring and
bent alignment tabs (Fig. 35) (Fig. 36). Check the
bearings for normal wear patterns, scoring, grooving,
fatigue and pitting (Fig. 37). Replace any bearing
that shows abnormal wear.
Inspect the connecting rod journals for signs of
scoring, nicks and burrs.
Misaligned or bent connecting rods can cause
abnormal wear on pistons, piston rings, cylinder
walls, connecting rod bearings and crankshaft con-
necting rod journals. If wear patterns or damage to
any of these components indicate the probability of a
misaligned connecting rod, inspect it for correct rod
alignment. Replace misaligned, bent or twisted con-
necting rods.
Fig. 33 Crankshaft / Camshaft Chain Drive
InstallationÐTypical
1 - CAMSHAFT SPROCKET
2 - TIMING MARKS
3 - CRANKSHAFT SPROCKET
Fig. 34 Timing Case Cover Components
1 - TIMING CASE COVER
2 - OIL SLINGER
3 - CRANKSHAFT OIL SEAL
4 - VIBRATION DAMPER PULLEY
Fig. 35 Connecting Rod Bearing Inspection
1 - UPPER BEARING HALF
2 - MATING EDGES
3 - GROOVES CAUSED BY ROD BOLTS SCRATCHING
JOURNAL DURING INSTALLATION
4 - WEAR PATTERN - ALWAYS GREATER ON UPPER BEARING
5 - LOWER BEARING HALF
WJENGINE - 4.0L 9 - 33
CAMSHAFT & BEARINGS (Continued)

(e) If end play is not within specification, inspect
crankshaft thrust faces for wear. If no wear is
apparent, replace the thrust bearing and measure
end play. If end play is still not within specifica-
tion, replace the crankshaft.
(11) If the crankshaft was removed, install the
crankshaft into the cylinder block.
(12) Install main bearing cap brace tighten nuts to
47 N´m (35 ft. lbs.) torque.
(13) Install oil pump assy. and tighten attaching
bolts to 23 N´m (17 ft. lbs.)
(14) Install the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - INSTALLATION).
(15) Install the drain plug. Tighten the plug to 34
N´m (25 ft. lbs.) torque.
(16) Lower the vehicle.
(17) Install the spark plugs. Tighten the plugs to
37 N´m (27 ft. lbs.) torque.
(18) Fill the oil pan with engine oil to the full
mark on the dipstick level.
(19) Connect negative cable to battery.
CRANKSHAFT OIL SEAL -
FRONT
REMOVAL
This procedure is done with the timing case cover
installed.
(1) Disconnect negative cable from battery.
(2) Remove the serpentine drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).(3) Remove the vibration damper (Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
REMOVAL).
(4) Remove the radiator shroud.
(5) Carefully remove the oil seal. Make sure seal
bore is clean.
INSTALLATION
This procedure is done with the timing case cover
installed.
(1) Position the replacement oil seal on Timing
Case Cover Alignment and Seal Installation Tool
6139 with seal open end facing inward. Apply a light
film of Perfect Seal, or equivalent, on the outside
diameter of the seal. Lightly coat the crankshaft with
engine oil.
(2) Position the tool and seal over the end of the
crankshaft and insert a draw screw tool into Seal
Installation Tool 6139 (Fig. 50). Tighten the nut
against the tool until it contacts the cover.
(3) Remove the tools. Apply a light film of engine
oil on the vibration damper hub contact surface of
the seal.
(4) Apply MopartSilicone Rubber Adhesive Seal-
ant to the keyway in the crankshaft and insert the
key. With the key inserted in the keyway in the
crankshaft, install the vibration damper (Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
INSTALLATION).
(5) Install the serpentine belt (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - INSTAL-
LATION).
(6) Install the radiator shroud.
(7) Connect negative cable to battery.
Fig. 49 Crankshaft End Play Measurement
1 - DIAL INDICATOR
2 - CRANKSHAFT
Fig. 50 Timing Case Cover Oil Seal Installation
1 - SEAL INSTALLATION TOOL
2 - DRAW SCREW TOOL
WJENGINE - 4.0L 9 - 41
CRANKSHAFT MAIN BEARINGS (Continued)

VIBRATION DAMPER
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove the serpentine drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL) and fan shroud.
(3) Remove the vibration damper retaining bolt
and washer.
(4) Use Vibration Damper Removal Tool 7697 to
remove the damper from the crankshaft (Fig. 70).
INSTALLATION
(1) Apply MopartSilicone Rubber Adhesive Seal-
ant to the keyway in the crankshaft and insert the
key. With the key in position, align the keyway on
the vibration damper hub with the crankshaft key
and tap the damper onto the crankshaft.
(2) Install the vibration damper retaining bolt and
washer.
(3) Tighten the damper retaining bolt to 108 N´m
(80 ft. lbs.) torque.
(4) Install the serpentine drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION) and fan shroud.
(5) Connect negative cable to battery.
STRUCTURAL SUPPORT
REMOVAL
The engine bending braces are used to add
strength to the powertrain and to address some
minor NVH concerns.
Fig. 68 Compression Ring Installation
1 - COMPRESSION RING
2 - RING EXPANDER RECOMMENDED
Fig. 69 Ring Gap Orientation
1 - TOP COMPRESSION RING
2 - BOTTOM COMPRESSION RING
3 - TOP OIL CONTROL RAIL
4 - OIL RAIL SPACER
5 - BOTTOM OIL CONTROL RAIL
6 - IMAGINARY LINE PARALLEL TO PISTON PIN
7 - IMAGINARY LINE THROUGH CENTER OF PISTON SKIRT
Fig. 70 Vibration Damper Removal Tool 7697
1 - VIBRATION DAMPER REMOVAL TOOL
2 - WRENCH
WJENGINE - 4.0L 9 - 49
PISTON RINGS (Continued)

INSTALLATION
A gear-type oil pump is mounted at the underside
of the cylinder block opposite the No.4 main bearing.
(1) Install the oil pump on the cylinder block using
a replacement gasket. Tighten the bolts to 23 N´m
(17 ft. lbs.) torque.
(2) Install the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - INSTALLATION).
(3) Fill the oil pan with oil to the specified level.
INTAKE MANIFOLD
DESCRIPTION
The intake manifold (Fig. 83) is made of cast alu-
minum and uses eleven bolts to mount to the cylin-
der head. This mounting style improves sealing and
reduces the chance of leaks.
DIAGNOSIS AND TESTING - INTAKE
MANIFOLD LEAKAGE
An intake manifold air leak is characterized by
lower than normal manifold vacuum. Also, one or
more cylinders may not be functioning.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS OR THE FAN.
DO NOT WEAR LOOSE CLOTHING.
(1) Start the engine.
(2) Spray a small stream of water at the suspected
leak area.
(3) If a change in RPM is observed the area of the
suspected leak has been found.
(4) Repair as required.
REMOVAL
NOTE: THE ENGINE INTAKE AND EXHAUST MANI-
FOLD MUST BE REMOVED AND INSTALLED
TOGETHER. THE MANIFOLDS USE A COMMON
GASKET AT THE CYLINDER HEAD.
(1) Disconnect the battery negative cable.
(2) Remove air cleaner inlet hose from the resona-
tor assembly.
(3) Remove the air cleaner assembly.
(4) Remove the throttle cable, vehicle speed control
cable (if equipped) and the transmission line pres-
sure cable (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - AW4/THROTTLE VALVE
CABLE - REMOVAL).
(5) Disconnect the following electrical connections
and secure their harness out of the way:
²Throttle Position Sensor
²Idle Air Control Motor
²Coolant Temperature Sensor (at thermostat
housing)
²Intake Air Temperature Sensor
²Oxygen Sensor
²Crank Position Sensor
²Six (6) Fuel Injector Connectors
²Manifold Absolute Pressure (MAP) Sensor.
(6) Disconnect HVAC, and Brake Booster vacuum
supply hoses at the intake manifold.
(7) Perform the fuel pressure release procedure.
(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY -
STANDARD PROCEDURE).
(8) Disconnect and remove the fuel system supply
line from the fuel rail assembly.
(9) Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(10) Remove the power steering pump from the
intake manifold and set aside.
(11) Raise the vehicle.
(12) Disconnect the exhaust pipes from the engine
exhaust manifolds.
(13) Lower the vehicle.
(14) Remove the intake manifold and exhaust
manifold bolts and manifolds (Fig. 84).
INSTALLATION
If the manifold is being replaced, ensure all the fit-
ting, etc. are transferred to the replacement mani-
fold.
(1) Install a new engine exhaust/intake manifold
gasket over the alignment dowels on the cylinder
head.
(2) Position the engine exhaust manifolds to the
cylinder head. Install fastener Number 3 and finger
tighten at this time (Fig. 84).
Fig. 83 Intake Manifold 4.0L Engine
WJENGINE - 4.0L 9 - 57
OIL PUMP (Continued)

(3) Install intake manifold on the cylinder head
dowels.
(4) Install washer and fastener Numbers 1, 2, 4, 5,
8, 9, 10 and 11 (Fig. 84).
(5) Install washer and fastener Numbers 6 and 7
(Fig. 84).
(6) Tighten the fasteners in sequence and to the
specified torque (Fig. 84).
²Fastener Numbers 1 through 5ÐTighten to 33
N´m (24 ft. lbs.) torque.
²Fastener Numbers 6 and 7ÐTighten to 31 N´m
(23 ft. lbs.) torque.
²Fastener Numbers 8 through 11ÐTighten to 33
N´m (24 ft. lbs.) torque.
(7) Install the power steering pump to the intake
manifold.
(8) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(9) Install the fuel system supply line to the fuel
rail assembly.
(10) Connect all electrical connections on the
intake manifold.
(11) Connect the vacuum hoses previously
removed.
(12) Install throttle cable, vehicle speed control
cable (if equipped).
(13) Install the transmission line pressure cable (if
equipped) (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - AW4/THROTTLE VALVE
CABLE - INSTALLATION).
(14) Install air cleaner assembly.
(15) Connect air inlet hose to the resonator assem-
bly.
(16) Raise the vehicle.
(17) Connect the exhaust pipes to the engine
exhaust manifolds. Tighten the bolts to 31 N´m (23
ft. lbs.)
(18) Lower the vehicle.(19) Connect the battery negative cable.
(20) Start the engine and check for leaks.
EXHAUST MANIFOLD
DESCRIPTION
The two exhaust manifolds (Fig. 85) are log style
and are made of high silicon molybdenum cast iron.
The exhaust manifolds share a common gasket with
the intake manifold. The exhaust manifolds also
incorporate ball flange outlets for improved sealing
and strain free connections.
REMOVAL
The intake and engine exhaust manifolds on the
4.0L engine must be removed together. The manifolds
use a common gasket at the cylinder head.
(Refer to 9 - ENGINE/MANIFOLDS/INTAKE
MANIFOLD - REMOVAL).
INSTALLATION
(1) The exhaust manifold and the intake manifold
must be installed together using a common gasket.
(2) (Refer to 9 - ENGINE/MANIFOLDS/INTAKE
MANIFOLD - INSTALLATION).
TIMING BELT / CHAIN
COVER(S)
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove the vibration damper (Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
REMOVAL).
(3) Remove the fan, hub assembly and fan shroud
(Refer to 7 - COOLING/ENGINE/RADIATOR FAN -
REMOVAL).
(4) Remove the accessory drive brackets that are
attached to the timing case cover.
(5) Remove the A/C compressor (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/A/C
COMPRESSOR - REMOVAL) (if equipped) and gen-
erator bracket assembly from the engine cylinder
head and move to one side.
(6) Remove the oil pan-to-timing case cover bolts
and timing case cover-to-cylinder block bolts.
(7) Remove the timing case cover and gasket from
the engine.
(8) Pry the crankshaft oil seal from the front of the
timing case cover (Fig. 86).
INSTALLATION
Clean the timing case cover, oil pan and cylinder
block gasket surfaces.
Fig. 84 Intake and Exhaust Manifolds Installation
9 - 58 ENGINE - 4.0LWJ
INTAKE MANIFOLD (Continued)

(1) Install a new crankshaft oil seal in the timing
case cover. The open end of the seal should be toward
the inside of the cover. Support the cover at the seal
area while installing the seal. Force it into position
with Seal Installation Tool 6139.
(2) Position the gasket on the cylinder block.
(3) Position the timing case cover on the oil pan
gasket and the cylinder block.
(4) Insert Timing Case Cover Alignment and Seal
Installation Tool 6139 in the crankshaft opening in
the cover (Fig. 87).
(5) Install the timing case cover-to-cylinder block
and the oil pan-to-timing case cover bolts.
(6) Tighten the 1/4 inch cover-to-block bolts to 7
N´m (60 in. lbs.) torque. Tighten the 5/16 inch front
cover-to-block bolts to 22 N´m (192 in. lbs.) torque.
Tighten the oil pan-to-cover 1/4 inch bolts to 9.5 N´m
(84 in. lbs.) torque.(7) Remove the cover alignment tool.
(8) Apply a light film of engine oil on the vibration
damper hub contact surface of the seal.
(9) Apply MopartSilicone Rubber Adhesive Seal-
ant to the keyway in the crankshaft and insert the
key. With the key inserted in the keyway in the
crankshaft, install the vibration damper (Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
INSTALLATION).
(10) Install the A/C compressor (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/A/C
COMPRESSOR - INSTALLATION) (if equipped) and
generator bracket assembly.
(11) Install the engine fan, hub assembly and
shroud (Refer to 7 - COOLING/ENGINE/RADIATOR
FAN - INSTALLATION).
(12) Install the serpentine drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(13) Connect negative cable to battery.
Fig. 85 EXHAUST MANIFOLDS 4.0L ENGINE
Fig. 86 Timing Case Cover Components
1 - TIMING CASE COVER
2 - OIL SLINGER
3 - CRANKSHAFT OIL SEAL
4 - VIBRATION DAMPER PULLEYFig. 87 Timing Case Cover Alignment
1 - TIMING CASE COVER ALIGNMENT AND SEAL
INSTALLATION TOOL
WJENGINE - 4.0L 9 - 59
TIMING BELT / CHAIN COVER(S) (Continued)

TIMING BELT/CHAIN AND
SPROCKETS
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove the fan and shroud (Refer to 7 -
COOLING/ENGINE/RADIATOR FAN - REMOVAL).
(3) Remove the serpentine drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(4) Remove the crankshaft vibration damper (Refer
to 9 - ENGINE/ENGINE BLOCK/VIBRATION
DAMPER - REMOVAL).
(5) Remove the timing case cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - REMOVAL).
(6) Rotate crankshaft until the ª0º timing mark is
closest to and on the center line with camshaft
sprocket timing mark (Fig. 88).
(7) Remove the oil slinger from the crankshaft.
(8) Remove the camshaft sprocket bolt and washer
(Fig. 89).
(9) Remove the crankshaft sprocket, camshaft
sprocket and timing chain as an assembly.
(10) Installation of the timing chain with the tim-
ing marks on the crankshaft and camshaft sprockets
properly aligned ensures correct valve timing. A worn
or stretched timing chain will adversely affect valvetiming. If the timing chain deflects more than 12.7
mm (1/2 inch) replace it.
INSTALLATION
Assemble the timing chain, crankshaft sprocket
and camshaft sprocket with the timing marks
aligned (Fig. 88).
(1) Apply MopartSilicone Rubber Adhesive Seal-
ant to the keyway in the crankshaft and insert the
key. With the key in the keyway on the crankshaft,
install the assembly on the crankshaft and camshaft.
(2)
Install the camshaft sprocket bolt and washer
(Fig. 89). Tighten the bolt to 68 N´m (50 ft. lbs.) torque.
(3) To verify correct installation of the timing
chain, rotate the crankshaft 2 revolutions. The cam-
shaft and crankshaft sprocket timing mark should
align (Fig. 88).
(4) Install the crankshaft oil slinger.
(5) Replace the oil seal in the timing case cover
(Refer to 9 - ENGINE/ENGINE BLOCK/CRANK-
SHAFT OIL SEAL - FRONT - REMOVAL).
(6) Install the timing case cover and gasket (Refer
to 9 - ENGINE/VALVE TIMING/TIMING BELT /
CHAIN COVER(S) - INSTALLATION).
(7) With the key installed in the crankshaft key-
way, install the vibration damper (Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
INSTALLATION).
(8) Install the serpentine drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(9) Install the fan, hub assembly and shroud
(Refer to 7 - COOLING/ENGINE/RADIATOR FAN -
INSTALLATION).
(10) Connect negative cable to battery.
Fig. 88 CrankshaftÐCamshaft Alignment
1 - CAMSHAFT SPROCKET
2 - TIMING MARKS
3 - CRANKSHAFT SPROCKET
Fig. 89 Camshaft Sprocket and Thrust Plate
1 - CAMSHAFT
2 - CAMSHAFT SPROCKET W/INTEGRAL KEY
3 - BOLT AND WASHER
4 - THRUST PLATE
9 - 60 ENGINE - 4.0LWJ