2003 JEEP GRAND CHEROKEE engine 4.7 HO

(1) Lubricate upper main bearing halves with
clean engine oil.
CAUTION: When installing crankshaft, use care not
to damage bearing surfaces on the crankshaft.
NOTE: Apply sealant to the target wheel retaining
screws prior to installation.
(2) Install the crankshaft target wheel. Torque the
mounting screws to 22 N´m (21 ft. lbs.).
(3) Position crankshaft in cylinder block.
(4) Install the thrust washers (Fig. 55).
CAUTION: The bedplate to cylinder block mateing
surface must be coated with sealant prior to instal-
lation. Failure to do so will cause severe oil leaks.
NOTE: The installation time to install the bedplate
after the sealant has been applied is critical.
NOTE: Make sure that the bedplate and cylinder
block sealing surfaces are clean and free of oil or
other contaminants. Contaminants on the sealing
surfaces may cause main bearing distortion and/or
oil leaks.
(5) Apply a 2.5mm (0.100 inch) (Fig. 56) bead of
MopartGen II Silicone Rubber Adhesive sealant to
the cylinder block-to-bedplate mating surface as
shown (Fig. 57).(6) Coat the crankshaft main bearing journals
with clean engine oil and position the bedplate onto
the cylinder block.
NOTE: Lubricate the bedplate retaining bolts with
clean engine oil prior to installation.
(7) Install the bedplate retaining bolts, making
sure to place the stud bolts in the correct location,
Torque the bolts in the sequence shown (Fig. 58).
²Tighten boltsA± Lto 54 N´m (40 ft. lbs.)
²Tighten bolts1±10to 2.8 N´m (25 in. lbs.)
²Turn bolts1±10an additional 90É.
Fig. 55 Crankshaft Thrust Washer Installation
1 - CRANKSHAFT THRUST WASHER
Fig. 56 Cutting Aplicator to Achieve 2.5mm (0.100
in.) Bead
1 - CUT HERE
Fig. 57 Cylinder Block-to-Bedplate Sealent Bead
Location
1 - CYLINDER BLOCK
2 - SEALANT BEAD LOCATION
WJENGINE - 4.7L 9 - 113
CRANKSHAFT (Continued)

²Tighten boltsA1± A6to 27 N´m (20 ft. lbs.)
(8) Measure crankshaft end play. (Refer to 9 -
ENGINE/ENGINE BLOCK/CRANKSHAFT - STAN-
DARD PROCEDURE).
(9) Install the connecting rods and measure side
clearance. (Refer to 9 - ENGINE/ENGINE BLOCK/
CONNECTING ROD BEARINGS - STANDARD
PROCEDURE).
(10) Position the oil pan gasket/windage tray,
using a new o-ring, install the oil pickup tube.
Torque the bolt to 28N´n (20 ft. lbs.) torque the nuts
to 28N´m (20 ft. lbs.).
(11)
Install the oil pan. Torque the retaining bolts to
15 N´m (11 ft. lbs.) in the sequence shown (Fig. 59).
(12) Install the engine (Refer to 9 - ENGINE -
INSTALLATION).
CRANKSHAFT MAIN
BEARINGS
STANDARD PROCEDUREÐCRANKSHAFT MAIN
BEARING - FITTING
MAIN BEARING JOURNAL DIAMETER
(CRANKSHAFT REMOVED)
Crankshaft removed from the cylinder block.
Clean the oil off the main bearing journal.
Determine the maximum diameter of the journal
with a micrometer. Measure at two locations 90É
apart at each end of the journal.
The maximum allowable taper is 0.008mm (0.0004
inch.) and maximum out of round is 0.005mm (0.002
inch). Compare the measured diameter with the jour-
nal diameter specification (Main Bearing Fitting
Chart). Select inserts required to obtain the specified
bearing-to-journal clearance.
Fig. 58 Bedplate Tightening Sequence
1 - BEDPLATE
2 - CYLINDER BLOCK
Fig. 59 Oil Pan Tightening Sequence
9 - 114 ENGINE - 4.7LWJ
CRANKSHAFT (Continued)

CRANKSHAFT MAIN BEARING SELECTION
The main bearings are ªselect fitº to achieve proper
oil clearances. For main bearing selection, the crank-
shaft position sensor target wheel has grade identifi-
cation marks stamped into it (Fig. 60). These marks
are read from left to right, corresponding with jour-
nal number 1, 2, 3, 4 and 5. The crankshaft position
sensor target wheel is mounted to the number 8
counter weight on the crankshaft.
NOTE: Service main bearings are coded. These
codes identify what size (grade) the bearing is.
MAIN BEARING SELECTION CHARTÐ4.7L
GRADE SIZE mm
(in.)FOR USE WITH
MARKING JOURNAL SIZE
A0.008 mm
U/S63.488±63.496 mm
(0.0004 in.)
U/S(2.4996±2.4999 in.)
BNOMINAL 63.496±63.504 mm
(2.4999±2.5002 in.)
C0.008 mm
O/S63.504±63.512 mm
(0.0004 in.)
O/S(2.5002±2.5005 in.)
INSPECTION
Wipe the inserts clean and inspect for abnormal
wear patterns and for metal or other foreign material
imbedded in the lining. Normal main bearing insert
wear patterns are illustrated (Fig. 61).
NOTE: If any of the crankshaft journals are scored,
the crankshaft must be repaired or replaced.
Inspect the back of the inserts for fractures, scrap-
ings or irregular wear patterns.
Inspect the upper insert locking tabs for damage.
Replace all damaged or worn bearing inserts.
CRANKSHAFT OIL SEAL -
FRONT
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(3) Remove A/C compressor mouning fasteners and
set aside.
(4) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(5) Remove upper radiator hose.
(6) Disconnect electrical connector for fan mounted
inside radiator shroud.
(7) Remove radiator shroud attaching fasteners.
NOTE: Transmission cooler line snaps into shroud
lower right hand corner.
Fig. 60 Main Bearing Markings on Target Wheel
1 - REARMOST CRANKSHAFT COUNTER WEIGHT
2 - TARGET WHEEL
3 - MAIN BEARING SELECT FIT MARKINGS
Fig. 61 Main Bearing Wear Patterns
1 - UPPER INSERT
2 - NO WEAR IN THIS AREA
3 - LOW AREA IN BEARING LINING
4 - LOWER INSERT
WJENGINE - 4.7L 9 - 115
CRANKSHAFT MAIN BEARINGS (Continued)

(8) Remove radiator cooling fan and shroud (Refer
to 7 - COOLING/ENGINE/RADIATOR FAN -
REMOVAL).
(9) Remove crankshaft damper bolt.
(10) Remove damper using Special Tools 8513
Insert and 1026 Three Jaw Puller (Fig. 62).
(11) Using Special Tool 8511, remove crankshaft
front seal (Fig. 63).
INSTALLATION
CAUTION: To prevent severe damage to the Crank-
shaft, Damper or Special Tool 8512, thoroughly
clean the damper bore and the crankshaft nose
before installing Damper.
(1) Using Special Tool 8348 and 8512, install
crankshaft front seal (Fig. 64).
(2) Install vibration damper (Refer to 9 - ENGINE/
ENGINE BLOCK/VIBRATION DAMPER - INSTAL-
LATION).
(3) Install radiator cooling fan and shroud (Refer
to 7 - COOLING/ENGINE/RADIATOR FAN -
INSTALLATION).
(4) Install upper radiator hose.
(5) Install A/C compressor and tighten fasteners to
54 N´m (40 ft. lbs.).
(6) Install accessory drive belt refer (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).(7) Refill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(8) Connect negative cable to battery.
Fig. 62 Crankshaft DamperÐRemoval
1 - SPECIAL TOOL 8513 INSERT
2 - SPECIAL TOOL 1026
Fig. 63 Crankshaft Front SealÐRemoval
1 - SPECIAL TOOL 8511
Fig. 64 Crankshaft Front SealÐInstallation
1 - TIMING CHAIN COVER
2 - SPECIAL TOOL 8348
3 - SPECIAL TOOL 8512
9 - 116 ENGINE - 4.7LWJ
CRANKSHAFT OIL SEAL - FRONT (Continued)

CRANKSHAFT OIL SEAL -
REAR
REMOVAL
NOTE: This procedure can be performed in vehicle.
(1) If being preformed in vehicle, remove the
transmission.
(2) Remove the flexplate (Refer to 9 - ENGINE/
ENGINE BLOCK/FLEX PLATE - REMOVAL).
NOTE: The crankshaft oil seal CAN NOT be reused
after removal.
NOTE: The crankshaft rear oil seal remover Special
Tool 8506 must be installed deeply into the seal.
Continue to tighten the removal tool into the seal
until the tool can not be turned farther. Failure to
install tool correctly the first time will cause tool to
pull free of seal without removing seal from engine.
(3) Using Special Tool 8506 (Fig. 65), remove the
crankshaft rear oil seal.
INSTALLATION
(1) Position the magnetic seal guide Special Tool
8349±2 (Fig. 66) onto the crankshaft rear face. Then
position the crankshaft rear oil seal onto the guide.
(2) Using Special Tools 8349 Crankshaft Rear Oil
Seal Installer and C-4171 Driver Handle (Fig. 67),
with a hammer, tap the seal into place. Continue totap on the driver handle until the seal installer seats
against the cylinder block crankshaft bore.
(3) Install the flexplate.
(4) Install the transmission.
Fig. 65 Crankshaft Rear Oil Seal Removal
1 - REAR CRANKSHAFT SEAL
2 - SPECIAL TOOL 8506
Fig. 66 Crankshaft Rear Oil Seal Guide Special Tool
8349±2 and Oil
1 - REAR CRANKSHAFT SEAL
2 - SPECIAL TOOL 8349±2 GUIDE
Fig. 67 Crankshaft Rear Oil Seal Installation
1 - REAR CRANKSHAFT SEAL
2 - SPECIAL TOOL 8349±1 INSTALLER
3 - SPECIAL TOOL C-4171 HANDLE
WJENGINE - 4.7L 9 - 117

FLEX PLATE
REMOVAL
(1) Remove the transmission.
(2) Remove the bolts and flexplate.
INSTALLATION
(1) Position the flexplate onto the crankshaft and
install the bolts hand tight.
(2) Tighten the flexplate retaining bolts to 60 N´m
(45 ft. lbs.) in the sequence shown (Fig. 68).
(3) Install the transmission.
PISTON & CONNECTING ROD
DESCRIPTION
CAUTION: Do not use a metal stamp to mark con-
necting rods as damage may result, instead use ink
or a scratch awl.
The pistons are made of a high strength aluminum
alloy. The anodized top ring groove and crown has
been replaced with a coated top ring that is blue in
color on the bottom surface. Piston skirts are coated
with a solid lubricant (Molykote) to reduce friction
and provide scuff resistance. The connecting rods are
made of forged powdered metal, with a ªfractured
capº design. A pressed fit piston pin is used to attach
the piston and connecting rod on the 4.7L. The 4.7L
HO uses a full floating piston pin.
STANDARD PROCEDUREÐPISTON FITTING
(1) To correctly select the proper size piston, a cyl-
inder bore gauge, capable of reading in 0.003 mm (
.0001 in.) INCREMENTS is required. If a bore gauge
is not available, do not use an inside micrometer.
(2) Measure the inside diameter of the cylinder
bore at a point 38.0 mm (1.5 inches) below top of
bore. Start perpendicular (across or at 90 degrees) to
the axis of the crankshaft at point A and then take
an additional bore reading 90 degrees to that at point
B (Fig. 70).
(3) The coated pistons will be serviced with the
piston pin and connecting rod pre-assembled.
(4) The coating material is applied to the piston
after the final piston machining process. Measuring
the outside diameter of a coated piston will not pro-
vide accurate results (Fig. 69). Therefore measuring
the inside diameter of the cylinder bore with a dial
Bore Gauge isMANDATORY. To correctly select the
proper size piston, a cylinder bore gauge capable of
reading in 0.003 mm (.0001 in.) increments is
required.
(5) Piston installation into the cylinder bore
requires slightly more pressure than that required
for non-coated pistons. The bonded coating on the
piston will give the appearance of a line-to-line fit
with the cylinder bore.
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove the following components:
²Oil pan and gasket/windage tray (Refer to 9 -
ENGINE/LUBRICATION/OIL PAN - REMOVAL).
²Cylinder head covers (Refer to 9 - ENGINE/
CYLINDER HEAD/CYLINDER HEAD COVER(S) -
Fig. 68 Flexplate Tightening Sequence
1 - FLEXPLATE
Fig. 69 Moly Coated PistonÐTypical
1 - MOLY COATED
2 - MOLY COATED
9 - 118 ENGINE - 4.7LWJ

REMOVAL) and (Refer to 9 - ENGINE/CYLINDER
HEAD/CYLINDER HEAD COVER(S) - REMOVAL).
²Timing chain cover (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT / CHAIN COVER(S)
- REMOVAL).
²Cylinder head(s) (Refer to 9 - ENGINE/CYLIN-
DER HEAD - REMOVAL) and (Refer to 9 - ENGINE/
CYLINDER HEAD - REMOVAL).
(3) If necessary, remove top ridge of cylinder bores
with a reliable ridge reamer before removing pistons
from cylinder block.Be sure to keep tops of pis-
tons covered during this operation.Pistons and
connecting rods must be removed from top of cylinder
block. When removing piston and connecting rod
assemblies from the engine, rotate crankshaft so the
each connecting rod is centered in cylinder bore.
CAUTION: DO NOT use a number stamp or a punch
to mark connecting rods or caps, as damage to
connecting rods could occur
NOTE: Connecting rods and bearing caps are not
interchangeable and should be marked before
removing to ensure correct reassembly.(4) Mark connecting rod and bearing cap positions
using a permanent ink marker or scribe tool (Fig.
71).
CAUTION: Care must be taken not to damage the
fractured rod and cap joint face surfaces, as engine
damage may occur.
(5) Remove connecting rod cap. Install Special Tool
8507 Connecting Rod Guides into the connecting rod
being removed. Remove piston from cylinder bore.
Repeat this procedure for each piston being removed.
CAUTION: Care must be taken not to nick crank-
shaft journals, as engine damage may occur
(6) Immediately after piston and connecting rod
removal, install bearing cap on the mating connect-
ing rod to prevent damage to the fractured cap and
rod surfaces.
(7) Carefully remove piston rings from piston(s),
starting from the top ring down.
CLEANING
CAUTION: DO NOT use a wire wheel or other abra-
sive cleaning devise to clean the pistons or con-
necting rods. The pistons have a Moly coating, this
coating must not be damaged.
(1) Using a suitable cleaning solvent clean the pis-
tons in warm water and towel dry.
(2) Use a wood or plastic scraper to clean the ring
land grooves.
CAUTION: DO NOT remove the piston pin from the
piston and connecting rod assembly.
INSPECTION
Check the connecting rod journal for excessive
wear, taper and scoring (Refer to 9 - ENGINE/EN-
GINE BLOCK/CONNECTING ROD BEARINGS -
STANDARD PROCEDURE).
Fig. 70 Bore GaugeÐTypical
1 - FRONT
2 - BORE GAUGE
3 - CYLINDER BORE
4-38MM
(1.5 in)
Fig. 71 Identify Connecting Rod to Cylinder
PositionÐTypical
WJENGINE - 4.7L 9 - 119
PISTON & CONNECTING ROD (Continued)

Check the connecting rod for signs of twist or bend-
ing.
Check the piston for taper and elliptical shape
before it is fitted into the cylinder bore (Refer to 9 -
ENGINE/ENGINE BLOCK/PISTON & CONNECT-
ING ROD - STANDARD PROCEDURE).
Check the piston for scoring, or scraping marks in
the piston skirts. Check the ring lands for cracks
and/or deterioration.
INSTALLATION
(1) Before installing piston and connecting rod
assemblies into the bore, install the piston rings.
(2)
Immerse the piston head and rings in clean
engine oil. Position a ring compressor over the piston
and rings. Tighten ring compressor.Ensure position
of rings do not change during this operation.
(3)Position bearing onto connecting rod. Ensure that
hole in bearing shell aligns with hole in connecting rod.
Lubricate bearing surface with clean engine oil.
(4) Install Special Tool 8507 Connecting Rod
Guides into connecting rod bolt threads (Fig. 72).(5) The pistons are marked on the piston pin bore
surface with an raised ªFº indicating installation
position. This mark must be pointing toward the
front of engine on both cylinder banks. The connect-
ing rod oil slinger slot faces the front of the engine
(Fig. 73).
(6) Wipe cylinder bore clean and lubricate with
engine oil.
(7) Rotate crankshaft until connecting rod journal
is on the center of cylinder bore. Insert rod and pis-
ton into cylinder bore and carefully position connect-
ing rod guides over crankshaft journal.
(8) Tap piston down in cylinder bore using a ham-
mer handle. While at the same time, guide connect-
ing rod into position on rod journal.
CAUTION: Connecting Rod Bolts are Torque to
Yield Bolts and Must Not Be Reused. Always
replace the Rod Bolts whenever they are loosened
or removed.
(9) Lubricate rod bolts and bearing surfaces with
engine oil. Install connecting rod cap and bearing.
Tighten bolts to 27 N´m (20 ft. lbs.) plus 90É.
(10) Install the following components:
²Cylinder head(s). (Refer to 9 - ENGINE/CYLIN-
DER HEAD - INSTALLATION).
²Timing chain and cover. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT / CHAIN COVER(S)
- INSTALLATION).
Fig. 72 Piston and Connecting RodÐInstallation
1 - ªFº TOWARD FRONT OF ENGINE
2 - OIL SLINGER SLOT
3 - RING COMPRESSOR
4 - SPECIAL TOOL 8507
Fig. 73 Piston and Connecting Rod Orientation
1 - MAJOR THRUST SIDE OF PISTON
2 - OIL SLINGER SLOT
9 - 120 ENGINE - 4.7LWJ
PISTON & CONNECTING ROD (Continued)