2002 JEEP GRAND CHEROKEE parts

CRANKSHAFT OIL SEAL -
REAR
REMOVAL
The crankshaft rear main bearing oil seal consists
of two half pieces of viton with a single lip that effec-
tively seals the rear of the crankshaft. Replace the
upper and lower seal halves as a unit to ensure leak-
free operation.
(1) Remove transmission inspection cover.
(2) Remove oil pan. (Refer to 9 - ENGINE/LUBRI-
CATION/OIL PAN - REMOVAL)
(3) Remove main bearing cap brace.
(4) Remove rear main bearing cap (No.7).
(5) Push upper seal out of the groove. Ensure that
the crankshaft and seal groove are not damaged.
(6) Remove lower half of the seal from the bearing
cap.
INSTALLATION
The crankshaft rear main bearing oil seal consists
of two half pieces of viton with a single lip that effec-
tively seals the rear of the crankshaft. Replace the
upper and lower seal halves as a unit to ensure leak-
free operation.
(1) Wipe the seal surface area of the crankshaft
until it is clean.
(2) Apply a thin coat of engine oil.
(3) Coat lip of the seal with engine oil.
(4) Carefully position the upper seal into the
groove in the cylinder block. The lip of the seal faces
toward the front of the engine.
(5) Apply MopartGasket Maker sealer on both
sides of cylinder block as shown in (Fig. 51). The dab
of sealer should be 3 mm (0.125 in.) in diameter.
(6) Apply MopartGasket Maker on the rear bear-
ing cap (Fig. 51). The bead should be 2.3 mm (0.09
in.) in diameter. DO NOT apply sealer to the lip of
the seal.
(7) Position the lower seal into the bearing cap
recess and seat it firmly. Be sure the seal is flush
with the cylinder block pan rail.
(8) Coat the outer curved surface of the lower seal
with soap and the lip of the seal with engine oil.
(9) Install the rear main bearing cap. DO NOT
strike the cap more than twice for proper engage-
ment.
(10) Tighten all main bearing bolts to 108 N´m (80
ft. lbs.) torque.
(11) Install the main bearing cap brace. Tighten
nuts to 47 N´m (35 ft. lbs.).
(12) Install the oil pan gasket and oil pan (Refer to
9 - ENGINE/LUBRICATION/OIL PAN - INSTALLA-
TION).(13) Apply MopartSilicone Rubber Adhesive Seal-
ant on cylinder block to rear main bearing cap cor-
ners and cylinder block to front cover joints (four
places) (Fig. 52)
(14) Install transmission inspection cover.
Fig. 51 Location of Sealer
1-DOWEL
2-SEALER LOCATIONS
3-CYLINDER BLOCK
4-HALFWAY BETWEEN
5-REAR FACE OF CYLINDER BLOCK
6-3mm (0.125 in.)
Fig. 52 Oil Pan
1 - SEALER LOCATIONS
9 - 42 ENGINE - 4.0LWJ

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)

(10) Place a piece of wood (2 x 2) between the jack
stand and the engine vibration damper.
(11) Remove the engine mount through bolts.
(12) Using the jack stand, raise the engine until
adequate clearance is obtained to remove the oil pan.
(13) Remove transmission oil cooling lines (if
equipped) and oxygen sensor wiring supports that
are attached to the oil pan studs.
(14) Remove the oil pan bolts and studs. Carefully
slide the oil pan and gasket to the rear. If equipped
with an oil level sensor, take care not to damage the
sensor.
INSTALLATION
(1) Clean the block and pan gasket surfaces.
(2) Fabricate 4 alignment dowels from 1 1/2 x 1/4
inch bolts. Cut the head off the bolts and cut a slot
into the top of the dowel. This will allow easier
installation and removal with a screwdriver (Fig. 78).
(3) Install two dowels in the timing case cover.
Install the other two dowels in the cylinder block
(Fig. 79).
(4) Apply MopartSilicone Rubber Adhesive Seal-
ant on cylinder block to rear main bearing cap cor-
ners and cylinder block to front cover joints (four
places) (Fig. 80).
(5) Slide the one-piece gasket over the dowels and
onto the block and timing case cover.
(6) Position the oil pan over the dowels and onto
the gasket. If equipped with an oil level sensor, take
care not to damage the sensor.
(7) Install the 1/4 inch oil pan bolts. Tighten these
bolts to 9.5 N´m (84 in. lbs.) torque. Install the 5/16
inch oil pan bolts (Fig. 81). Tighten these bolts to 15
N´m (132 in. lbs.) torque.
(8) Remove the dowels. Install the remaining 1/4
inch oil pan bolts. Tighten these bolts to 9.5 N´m (84
in. lbs.) torque.
Fig. 78 Fabrication of Alignment Dowels
1 - 1/488ý 1 1/288BOLT
2 - DOWEL
3 - SLOT
Fig. 79 Position of Dowels in Cylinder Block
1 - DOWEL HOLES
2 - CYLINDER BLOCK
3 - 5/1688HOLES
4 - 5/1688HOLES
Fig. 80 Oil Pan Sealer Location
1 - SEALER LOCATIONS
Fig. 81 Position of 5/16 inch Oil Pan Bolts
1 - OIL PAN
2 - OIL PAN DRAIN PLUG
WJENGINE - 4.0L 9 - 55
OIL PAN (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

CONDITION POSSIBLE CAUSES CORRECTIONS
MAIN BEARING NOISE 1. Insufficient oil supply. 1. (Refer to LUBRICATION &
MAINTENANCE/FLUID TYPES -
SPECIFICATIONS).
2. Low oil pressure. 2. Check oil pump, if Ok, check rod
and main bearings for excessive wear.
3. Thin or diluted oil. 3. Change oil and filter.
4. Excessive bearing clearance. 4. Replace as necessary.
5. Excessive end play. 5. Check thrust washers for wear.
6. Crankshaft journal out-of round. 6. Service or replace crankshaft.
7. Loose flywheel or torque
converter.7. Tighten to correct torque
DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - LUBRICATION
CONDITION POSSIBLE CAUSES CORRECTION
OIL LEAKS 1. Gaskets and O-Rings. 1.
(a) Misaligned or damaged. (a) Replace as necessary.
(b) Loose fasteners, broken or
porous metal parts.(b) Tighten fasteners, Repair or
replace metal parts.
2. Crankshaft rear seal 2. Replace as necessary (Refer to 9 -
ENGINE/ENGINE BLOCK/
CRANKSHAFT OIL SEAL - REAR -
REMOVAL).
3. Crankshaft seal flange.
Scratched, nicked or grooved.3. Polish or replace crankshaft.
4. Oil pan flange cracked. 4. Replace oil pan (Refer to 9 -
ENGINE/LUBRICATION/OIL PAN -
REMOVAL).
5. Timing chain cover seal, damaged
or misaligned.5. Replace seal (Refer to 9 -
ENGINE/ENGINE BLOCK/
CRANKSHAFT OIL SEAL - FRONT -
REMOVAL).
6. Scratched or damaged vibration
damper hub.6. Polish or replace damper.
WJENGINE - 4.7L 9 - 67
ENGINE - 4.7L (Continued)

STANDARD PROCEDURE
STANDARD PROCEDURE - REPAIR DAMAGED
OR WORN THREADS
CAUTION: Be sure that the tapped holes maintain
the original center line.
Damaged or worn threads can be repaired. Essen-
tially, this repair consists of:
²Drilling out worn or damaged threads.
²Tapping the hole with a special Heli-Coil Tap, or
equivalent.
²Installing an insert into the tapped hole to bring
the hole back to its original thread size.
STANDARD PROCEDURE - FORM-IN-PLACE
GASKETS AND SEALERS
There are numerous places where form-in-place
gaskets are used on the engine. Care must be taken
when applying form-in-place gaskets to assure
obtaining the desired results.Do not use form-in-
place gasket material unless specified.Bead size,
continuity, and location are of great importance. Too
thin a bead can result in leakage while too much can
result in spill-over which can break off and obstruct
fluid feed lines. A continuous bead of the proper
width is essential to obtain a leak-free gasket.
There are numerous types of form-in-place gasket
materials that are used in the engine area. Mopart
Engine RTV GEN II, MopartATF-RTV, and Mopart
Gasket Maker gasket materials, each have different
properties and can not be used in place of the other.
MOPARtENGINE RTV GEN II
MopartEngine RTV GEN II is used to seal com-
ponents exposed to engine oil. This material is a spe-
cially designed black silicone rubber RTV that
retains adhesion and sealing properties when
exposed to engine oil. Moisture in the air causes the
material to cure. This material is available in three
ounce tubes and has a shelf life of one year. After one
year this material will not properly cure. Always
inspect the package for the expiration date before
use.
MOPARtATF RTV
MopartATF RTV is a specifically designed black
silicone rubber RTV that retains adhesion and seal-
ing properties to seal components exposed to auto-
matic transmission fluid, engine coolants, and
moisture. This material is available in three ounce
tubes and has a shelf life of one year. After one year
this material will not properly cure. Always inspect
the package for the expiration date before use.
MOPARtGASKET MAKER
MopartGasket Maker is an anaerobic type gasket
material. The material cures in the absence of airwhen squeezed between two metallic surfaces. It will
not cure if left in the uncovered tube. The anaerobic
material is for use between two machined surfaces.
Do not use on flexible metal flanges.
MOPARtGASKET SEALANT
MopartGasket Sealant is a slow drying, perma-
nently soft sealer. This material is recommended for
sealing threaded fittings and gaskets against leakage
of oil and coolant. Can be used on threaded and
machined parts under all temperatures. This mate-
rial is used on engines with multi-layer steel (MLS)
cylinder head gaskets. This material also will pre-
vent corrosion. MopartGasket Sealant is available in
a 13 oz. aerosol can or 4oz./16 oz. can w/applicator.
FORM-IN-PLACE GASKET AND SEALER
APPLICATION
Assembling parts using a form-in-place gasket
requires care but it's easier then using precut gas-
kets.
MopartGasket Maker material should be applied
sparingly 1 mm (0.040 in.) diameter or less of sealant
to one gasket surface. Be certain the material sur-
rounds each mounting hole. Excess material can eas-
ily be wiped off. Components should be torqued in
place within 15 minutes. The use of a locating dowel
is recommended during assembly to prevent smear-
ing material off the location.
MopartEngine RTV GEN II or ATF RTV gasket
material should be applied in a continuous bead
approximately 3 mm (0.120 in.) in diameter. All
mounting holes must be circled. For corner sealing, a
3.17 or 6.35 mm (1/8 or 1/4 in.) drop is placed in the
center of the gasket contact area. Uncured sealant
may be removed with a shop towel. Components
should be torqued in place while the sealant is still
wet to the touch (within 10 minutes). The usage of a
locating dowel is recommended during assembly to
prevent smearing material off the location.
MopartGasket Sealant in an aerosol can should be
applied using a thin, even coat sprayed completely
over both surfaces to be joined, and both sides of a
gasket. Then proceed with assembly. Material in a
can w/applicator can be brushed on evenly over the
sealing surfaces. Material in an aerosol can should be
used on engines with multi-layer steel gaskets.
STANDARD PROCEDURE - ENGINE GASKET
SURFACE PREPARATION
To ensure engine gasket sealing, proper surface
preparation must be performed, especially with the
use of aluminum engine components and multi-layer
steel cylinder head gaskets.
Neveruse the following to clean gasket surfaces:
²Metal scraper
9 - 70 ENGINE - 4.7LWJ
ENGINE - 4.7L (Continued)

(4) For rocker arm installation on cylinders 1 and
7 Rotate the crankshaft until cylinder #2 is at TDC
compression stroke.
(5) Using special tool 8516 press downward on the
valve spring, install rocker arm (Fig. 44).
(6) Install the cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
VALVE SPRINGS
DESCRIPTION
The valve springs are made from high strength
chrome silicon steel. The springs are common for
intake and exhaust applications. The valve spring
seat is integral with the valve stem seal, which is a
positive type seal to control lubrication.
VALVE STEM SEALS
DESCRIPTION
The valve stem seals are made of rubber and incor-
porate an integral steel valve spring seat. The inte-
gral garter spring maintains consistent lubrication
control to the valve stems.
ENGINE BLOCK
DESCRIPTION
The cylinder block is made of cast iron. The block
is a closed deck design with the left bank forward. To
provide high rigidity and improved NVH an
enhanced compacted graphite bedplate is bolted to
the block. The block design allows coolant flow
between the cylinders bores, and an internal coolant
bypass to a single poppet inlet thermostat is included
in the cast aluminum front cover.
STANDARD PROCEDUREÐCYLINDER BORE
HONING
Before honing, stuff plenty of clean shop towels
under the bores and over the crankshaft to keep
abrasive materials from entering the crankshaft
area.
(1) Used carefully, the Cylinder Bore Sizing Hone
C-823, equipped with 220 grit stones, is the best tool
for this job. In addition to deglazing, it will reduce
taper and out-of-round, as well as removing light
scuffing, scoring and scratches. Usually, a few strokes
will clean up a bore and maintain the required lim-
its.CAUTION: DO NOT use rigid type hones to remove
cylinder wall glaze.
(2) Deglazing of the cylinder walls may be done if
the cylinder bore is straight and round. Use a cylin-
der surfacing hone, Honing Tool C-3501, equipped
with 280 grit stones (C-3501-3810). about 20-60
strokes, depending on the bore condition, will be suf-
ficient to provide a satisfactory surface. Using honing
oil C-3501-3880, or a light honing oil, available from
major oil distributors.
CAUTION: DO NOT use engine or transmission oil,
mineral spirits, or kerosene.
(3) Honing should be done by moving the hone up
and down fast enough to get a crosshatch pattern.
The hone marks should INTERSECT at 50É to 60É
for proper seating of rings (Fig. 45).
(4) A controlled hone motor speed between 200 and
300 RPM is necessary to obtain the proper cross-
hatch angle. The number of up and down strokes per
minute can be regulated to get the desired 50É to 60É
angle. Faster up and down strokes increase the cross-
hatch angle.
(5) After honing, it is necessary that the block be
cleaned to remove all traces of abrasive. Use a brush
to wash parts with a solution of hot water and deter-
gent. Dry parts thoroughly. Use a clean, white, lint-
Fig. 45 Cylinder Bore Crosshatch Pattern
1 - CROSSHATCH PATTERN
2 - INTERSECT ANGLE
9 - 108 ENGINE - 4.7LWJ
ROCKER ARM / ADJUSTER ASSEMBLY (Continued)