2002 JEEP GRAND CHEROKEE Time

ground at all times. If not OK, repair the open
ground circuit to ground as required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the steering column opening cover
from the instrument panel. Refer toSteering Col-
umn Opening Coverin Body for the procedure.
(3) The power outlet / cigar lighter relay is located
on the left side of the combination flasher in the
junction block.
(4) Remove the power outlet / cigar lighter relay
from the junction block.
INSTALLATION
(1) Position the power outlet / cigar lighter relay in
the proper receptacle in the junction block.
(2) Align the power outlet / cigar lighter relay ter-
minals with the terminal cavities in the junction
block receptacle.
(3) Push in firmly on the power outlet / cigar
lighter relay until the terminals are fully seated in
the terminal cavities in the junction block receptacle.
(4) Install the steering column opening cover onto
the instrument panel. Refer toSteering Column
Opening Coverin Body for the procedure.
(5) Reconnect the battery negative cable.
IOD WIRE HARNESS
CONNECTOR
DESCRIPTION
All vehicles are equipped with an Ignition-Off
Draw (IOD) connector that is located in a molded
connector receptacle on the lower rear surface of the
Junction Block (JB) housing (Fig. 17). The JB is con-
cealed above the molded plastic instrument panel
fuse cover. Integral latches molded into the fuse
cover secure it the JB, the Body Control Module
(BCM) and the 16-way data link connector tab of the
instrument panel steering column support bracket.
The fuse cover can be pulled downward to disengage
the latches and provide service access to all of the
fuses, relays and wire harness connectors of the JB.
Refer toInstrument Panel Fuse Coverin the
index of this service manual for the location of addi-
tional service information covering the fuse cover.
OPERATION
The term ignition-off draw identifies a normal con-
dition where power is being drained from the battery
with the ignition switch in the Off position. The IOD
connector feeds the memory and sleep mode func-
tions for some of the electronic modules in the vehicleas well as various other accessories that require bat-
tery current when the ignition switch is in the Off
position, including the clock.
The IOD connector can be used by the vehicle
owner as a convenient means of reducing battery
depletion when a vehicle is to be stored for periods
not to exceed about twenty days (short-term storage).
Simply disconnect the IOD connector from the JB
receptacle. However, it must be remembered that dis-
connecting the IOD connector will not eliminate IOD,
but only reduce this normal condition. When a vehi-
cle will not be used for more than twenty days, but
less than thirty days, remove the IOD fuse from the
Power Distribution Center (PDC). If a vehicle will be
stored for more than about thirty days, the battery
negative cable should be disconnected to eliminate
normal IOD; and, the battery should be tested and
recharged at regular intervals during the vehicle
storage period to prevent the battery from becoming
discharged or damaged. Refer toIgnition-Off Draw
Fig. 17 Ignition-Off Draw Connector
1 - SNAP CLIPS
2 - SCREW
3 - CONNECTOR
4 - LEFT BODY WIRE HARNESS
5 - IOD CONNECTOR
6 - FUSED B+ CONNECTOR
7 - RIGHT BODY WIRE HARNESS
8 - SCREW
9 - CONNECTOR
10 - JUNCTION BLOCK
WJ8W-97 POWER DISTRIBUTION 8W - 97 - 15
POWER OUTLET RELAY (Continued)

the vehicle. The power outlet base and mount are
secured by a snap fit within the quarter trim panel.
A plastic protective cap snaps into the power outlet
base when the power outlet is not being used, and
hangs from the power outlet base mount by an inte-
gral bail strap while the power outlet is in use. While
the power outlet is very similar to a cigar lighter
base unit, it does not include the two small spring-
clip retainers inside the bottom of the receptacle
shell that are used to secure the cigar lighter heating
element to the insulated contact.
The power outlet receptacle unit and the accessory
power outlet protective cap are available for service.
The power outlet receptacle cannot be repaired and,
if faulty or damaged, it must be replaced.
OPERATION - REAR POWER OUTLET
The power outlet base or receptacle shell is con-
nected to ground, and an insulated contact in the
bottom of the shell is connected to battery current.
The power outlet receives battery voltage from a fuse
in the Power Distribution Center (PDC) through a
fuse in the Junction Block (JB) at all times. Refer to
Horn/Cigar Lighter/Power Outletin Wiring Dia-
grams for the location of complete rear power outlet
circuit diagrams.
DIAGNOSIS AND TESTING - REAR POWER
OUTLET
Refer toHorn/Cigar Lighter/Power Outletin
Wiring Diagrams for the location of complete rear
power outlet circuit diagrams.
(1) Check the fused B(+) fuse in the Junction
Block (JB). If OK, go to Step 2. If not OK, repair the
shorted circuit or component as required and replace
the faulty fuse.
(2) Check for battery voltage at the fused B(+) fuse
in the JB. If OK, go to Step 3. If not OK, repair the
open fused B(+) circuit to the Power Distribution
Center (PDC) as required.
(3) Remove the plastic protective cap from the rear
power outlet receptacle. Check for continuity between
the inside circumference of the rear power outlet
receptacle and a good ground. There should be conti-
nuity. If OK, go to Step 4. If not OK, go to Step 5.
(4) Check for battery voltage at the insulated con-
tact located at the back of the rear power outlet
receptacle. If not OK, go to Step 5.(5) Disconnect and isolate the battery negative
cable. Remove the rear power outlet from the right
quarter trim panel. Check for continuity between the
ground circuit cavity of the rear power outlet wire
harness connector and a good ground. There should
be continuity. If OK, go to Step 6. If not OK, repair
the open ground circuit to ground as required.
(6) Connect the battery negative cable. Check for
battery voltage at the fused B(+) circuit cavity of the
rear power outlet wire harness connector. If OK,
replace the faulty rear power outlet receptacle base.
If not OK, repair the open fused B(+) circuit to the
JB fuse as required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Pull the protective cap out of the rear power
outlet receptacle base (Fig. 20).
Fig. 20 Rear Power Outlet Remove/Install
1 - RIGHT QUARTER TRIM PANEL
2 - RIGHT BODY WIRE HARNESS CONNECTOR
3 - RECEPTACLE BASE
4 - PROTECTIVE CAP
5 - MOUNT
WJ8W-97 POWER DISTRIBUTION 8W - 97 - 17
REAR POWER OUTLET (Continued)

DIAGNOSIS AND TESTINGÐREAR SEAL AREA
LEAKS
Since it is sometimes difficult to determine the
source of an oil leak in the rear seal area of the
engine, a more involved inspection is necessary. The
following steps should be followed to help pinpoint
the source of the leak.
If the leakage occurs at the crankshaft rear oil seal
area:
(1) Disconnect the battery.
(2) Raise the vehicle.
(3) Remove torque converter or clutch housing
cover and inspect rear of block for evidence of oil.
Use a black light to check for the oil leak:
(a) Circular spray pattern generally indicates
seal leakage or crankshaft damage.
(b) Where leakage tends to run straight down,
possible causes are a porous block, distributor seal,
camshaft bore cup plugs, oil galley pipe plugs, oil
filter runoff, and main bearing cap to cylinder
block mating surfaces.
(4) If no leaks are detected, pressurized the crank-
case as outlined in (Refer to 9 - ENGINE/LUBRICA-
TION - DIAGNOSIS AND TESTING)
CAUTION: Do not exceed 20.6 kPa (3 psi).
(5) If the leak is not detected, very slowly turn the
crankshaft and watch for leakage. If a leak is
detected between the crankshaft and seal while
slowly turning the crankshaft, it is possible the
crankshaft seal surface is damaged. The seal area on
the crankshaft could have minor nicks or scratches
that can be polished out with emery cloth.
CAUTION: Use extreme caution when crankshaft
polishing is necessary to remove minor nicks or
scratches. The crankshaft seal flange is specially
machined to complement the function of the rear oil
seal.
(6) For bubbles that remain steady with shaft
rotation, no further inspection can be done until dis-
assembled. Refer to the service DiagnosisÐMechani-
cal, under the Oil Leak row, for components
inspections on possible causes and corrections.
(7) After the oil leak root cause and appropriate
corrective action have been identified, (Refer to 9 -
ENGINE/ENGINE BLOCK/CRANKSHAFT OIL
SEAL - REAR - REMOVAL), for proper replacement
procedures.
STANDARD PROCEDURE
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 air
when 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.
WJENGINE - 4.0L 9 - 9
ENGINE - 4.0L (Continued)

(2) Drain the coolant (Refer to 7 - COOLING -
STANDARD PROCEDURE) and disconnect the hoses
at the engine thermostat housing and the water
pump inlet. DO NOT waste reusable coolant. If the
solution is clean and is being drained only to service
the engine or cooling system, drain the coolant into a
clean container for reuse.
(3) Remove the air cleaner assembly (Refer to 9 -
ENGINE/AIR INTAKE SYSTEM/AIR CLEANER
HOUSING - REMOVAL).
(4) Remove the cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(5) Remove the capscrews, bridge and pivot assem-
blies and rocker arms (Refer to 9 - ENGINE/CYLIN-
DER HEAD/ROCKER ARM / ADJUSTER ASSY -
REMOVAL).
(6) Remove the push rods.Retain the push rods,
bridges, pivots and rocker arms in the same
order as removed.
(7) Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(8) Remove the A/C compressor mounting bolts
and secure the compressor to the side.
(9) Remove the power steering pump and bracket
from the intake manifold and water pump. Set the
pump and bracket aside. DO NOT disconnect the
hoses.
(10) Perform the Fuel System Pressure Release
procedure. (Refer to 14 - FUEL SYSTEM/FUEL
DELIVERY - STANDARD PROCEDURE).
(11) Disconnect the fuel supply line at the fuel rail.(12) Remove the intake and exhaust manifolds
from the engine cylinder head (Refer to 9 - ENGINE/
MANIFOLDS/INTAKE MANIFOLD - REMOVAL).
(13) Remove the coil rail (Refer to 8 - ELECTRI-
CAL/IGNITION CONTROL/COIL RAIL - REMOV-
AL).
(14) Remove spark plugs (Refer to 8 - ELECTRI-
CAL/IGNITION CONTROL/SPARK PLUG - REMOV-
AL).
(15) Disconnect the temperature sending unit wire
connector.
(16) Remove the engine cylinder head bolts. Bolt
No.14 cannot be removed until the head is moved for-
ward (Fig. 9). Pull bolt No.14 out as far as it will go
and then suspend the bolt in this position (tape
around the bolt).
(17) Remove the engine cylinder head and gasket
(Fig. 9).
(18) If this was the first time the bolts were
removed, put a paint dab on the top of the bolt. If the
bolts have a paint dab on the top of the bolt or it
isn't known if they were used before, discard the
bolts.
(19) Stuff clean lint free shop towels into the cyl-
inder bores.
NOTE: If the valves, springs, or seals are to be
inspected/replaced at this time, (Refer to 9 -
ENGINE/CYLINDER HEAD/INTAKE/EXHAUST
VALVES & SEATS - STANDARD PROCEDURE) for
proper inspection procedures.
Fig. 8 Cylinder Head 4.0L Engine
1 - CYLINDER HEAD BOLTS
2 - CYLINDER HEAD GASKET
3 - CYLINDER HEAD
Fig. 9 Engine Cylinder
1 - CYLINDER HEAD BOLTS
2 - CYLINDER HEAD GASKET
3 - CYLINDER HEAD
9 - 20 ENGINE - 4.0LWJ
CYLINDER HEAD (Continued)

(5) Position the valve spring and retainer on the
engine cylinder head and compress the valve spring
with Valve Spring Compressor Tool MD-998772A.
(6) Install the valve locks and release the tool.
(7) Tap the valve spring from side to side with a
hammer to ensure that the spring is properly seated
at the engine cylinder head. Also tap the top of the
retainer to seat the valve locks.
(8) Install the engine cylinder head (Refer to 9 -
ENGINE/CYLINDER HEAD - INSTALLATION).
ROCKER ARM / ADJUSTER
ASSEMBLY
DESCRIPTION
The rocker arms are made of stamped steel and
have a operational ratio of 1.6:1 (Fig. 21).
OPERATION
When the push rods are forced upward by the cam-
shaft lobes the push rod presses upward on the
rocker arms, the rocker arms pivot, forcing down-
ward pressure on the valves forcing the valves to
move downward and off from their seats.
REMOVAL
NOTE: This procedure can be done with the engine
in or out of the vehicle.
(1) Remove the cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(2) Check for rocker arm bridges which are caus-
ing misalignment of the rocker arm to valve tip area.
(3) Remove the capscrews at each bridge and pivot
assembly (Fig. 22). Alternately loosen the capscrews
one turn at a time to avoid damaging the bridges.
(4) Remove the bridges, pivots and corresponding
pairs of rocker arms (Fig. 22). Place them on a bench
in the same order as removed.
(5) Remove the push rods and place them on a
bench in the same order as removed.
CLEANING
Clean all the components with cleaning solvent.
Use compressed air to blow out the oil passages in
the rocker arms and push rods.
Fig. 20 Valve and Valve Components
1 - VALVE LOCKS (3±BEAD)
2 - RETAINER
3 - VALVE STEM OIL SEAL
4 - INTAKE VALVE
5 - EXHAUST VALVE
6 - VALVE SPRING
Fig. 21 Rocker ArmsÐTypical
1 - CAPSCREWS
2 - BRIDGE
3 - PIVOT ASSEMBLY
4 - PUSH RODS
5 - ROCKER ARMS
9 - 26 ENGINE - 4.0LWJ
INTAKE/EXHAUST VALVES & SEATS (Continued)

INSPECTION
Inspect the pivot surface area of each rocker arm.
Replace any that are scuffed, pitted, cracked or
excessively worn.
Inspect the valve stem tip contact surface of each
rocker arm and replace any rocker arm that is deeply
pitted.
Inspect each push rod end for excessive wear and
replace as required. If any push rod is excessively
worn because of lack of oil, replace it and inspect the
corresponding hydraulic tappet for excessive wear.
Inspect the push rods for straightness by rolling
them on a flat surface or by shining a light between
the push rod and the flat surface.
A wear pattern along the length of the push rod is
not normal. Inspect the engine cylinder head for
obstruction if this condition exists.
INSTALLATION
NOTE: This procedure can be done with the engine
in or out of the vehicle.
(1) Lubricate the ball ends of the push rods with
MopartEngine Oil Supplement, or equivalent and
install push rods in their original locations. Ensurethat the bottom end of each push rod is centered in
the tappet plunger cap seat.
(2) Using MopartEngine Oil Supplement, or
equivalent, lubricate the area of the rocker arm that
the pivot contacts. Install rocker arms, pivots and
bridge above each cylinder in their originally position
(Fig. 23).
(3) Loosely install the capscrews through each
bridge.
(4) At each bridge, tighten the capscrews alter-
nately, one turn at a time, to avoid damaging the
bridge. Tighten the capscrews to 28 N´m (21 ft. lbs.)
torque.
(5) Install the engine cylinder head cover (Refer to
9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
VALVE STEM SEALS
DESCRIPTION
The valve stem seals (Fig. 24) are made of rubber
and incorporate a garter spring to maintain consis-
tent lubrication control.
Fig. 22 Rocker Arm
1 - CAPSCREWS
2 - BRIDGE
3 - PIVOT ASSEMBLY
4 - PUSH RODS
5 - ROCKER ARMS
Fig. 23 Rocker Arm
1 - CAPSCREWS
2 - BRIDGE
3 - PIVOT ASSEMBLY
4 - PUSH RODS
5 - ROCKER ARMS
WJENGINE - 4.0L 9 - 27
ROCKER ARM / ADJUSTER ASSEMBLY (Continued)

ENGINE BLOCK
CLEANING
Thoroughly clean the oil pan and engine block gas-
ket surfaces.
Use compressed air to clean out:
²The galley at the oil filter adaptor hole.
²The front and rear oil galley holes.
²The feed holes for the crankshaft main bearings.
Once the block has been completely cleaned, apply
Loctite PST pipe sealant with Teflon 592 to the
threads of the front and rear oil galley plugs. Tighten
the plugs to 34 N´m (25 ft. lbs.) torque.
INSPECTION
(1) It is mandatory to use a dial bore gauge to
measure each cylinder bore diameter (Fig. 29). To
correctly select the proper size piston, a cylinder 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 three levels below top of bore. Start perpen-
dicular (across or at 90 degrees) to the axis of the
crankshaft and then take two additional reading.(3) Measure the cylinder bore diameter crosswise
to the cylinder block near the top of the bore. Repeat
the measurement near the middle of the bore, then
repeat the measurement near the bottom of the bore.
(4) Determine taper by subtracting the smaller
diameter from the larger diameter.
(5) Rotate measuring device 90É and repeat steps
above.
(6) Determine out-of-roundness by comparing the
difference between each measurement.
(7) If cylinder bore taper does not exceed 0.025
mm (0.001 inch) and out-of-roundness does not
exceed 0.025 mm (0.001 inch), the cylinder bore can
be honed. If the cylinder bore taper or out- of-round
condition exceeds these maximum limits, the cylinder
must be bored and then honed to accept an oversize
piston. A slight amount of taper always exists in the
cylinder bore after the engine has been in use for a
period of time.
CAMSHAFT & BEARINGS
DESCRIPTION
The camshaft is made of gray cast iron with twelve
machined lobes and four bearing journals (Fig. 30).
When the camshaft rotates the lobes actuate the tap-
pets and push rods, forcing upward on the rocker
arms which applies downward force on the valves.
Fig. 28 Valve and Valve
1 - VALVE LOCKS (3±BEAD)
2 - RETAINER
3 - VALVE STEM OIL SEAL
4 - INTAKE VALVE
5 - EXHAUST VALVE
6 - VALVE SPRINGFig. 29 Cylinder Bore Measurement
9 - 30 ENGINE - 4.0LWJ
VALVE SPRINGS (Continued)

CRANKSHAFT MAIN
BEARINGS
STANDARD PROCEDURE - FITTING
CRANKSHAFT MAIN BEARINGS
FITTING BEARINGS (CRANKSHAFT INSTALLED)
The main bearing caps, numbered (front to rear)
from 1 through 7 have an arrow to indicate the for-
ward position. The upper main bearing inserts are
grooved to provide oil channels while the lower
inserts are smooth.
Each bearing insert pair is selectively fitted to its
respective journal to obtain the specified operating
clearance. In production, the select fit is obtained by
using various-sized color-coded bearing insert pairs
as listed in the Main Bearing Fitting Chart. The
bearing color code appears on the edge of the insert.
The size is not stamped on bearing inserts used
for engine production.
The main bearing journal size (diameter) is identi-
fied by a color-coded paint mark (Fig. 42)on the adja-
cent cheek or counterweight towards the rear of the
crankshaft (flange end). The rear main journal, is
identified by a color-coded paint mark on the crank-
shaft rear flange.
When required, upper and lower bearing inserts of
different sizes may be used as a pair. A standard size
insert is sometimes used in combination with a 0.025
mm (0.001 inch) undersize insert to reduce the clear-
ance by 0.013 mm (0.0005 inch).Never use a pair
of bearing inserts with greater than a 0.025 mm
(0.001 inch) difference in size. Refer to the
Bearing Insert Pair Chart.NOTE: When replacing inserts, the odd size inserts
must be either all on the top (in cylinder block) or
all on the bottom (in main bearing cap).
Once the bearings have been properly fitted, (Refer
to 9 - ENGINE/ENGINE BLOCK/CRANKSHAFT
MAIN BEARINGS - INSTALLATION).
BEARING-TO-JOURNAL CLEARANCE (CRANKSHAFT
INSTALLED)
When using Plastigage, check only one bearing
clearance at a time.
Install the grooved main bearings into the cylinder
block and the non-grooved bearings into the bearing
caps.
Install the crankshaft into the upper bearings dry.
Place a strip of Plastigage across full width of the
crankshaft journal to be checked.
Install the bearing cap and tighten the bolts to 108
N´m (80 ft. lbs.) torque.
NOTE: DO NOT rotate the crankshaft. This will
cause the Plastigage to shift, resulting in an inaccu-
rate reading. Plastigage must not be permitted to
crumble. If brittle, obtain fresh stock.
Remove the bearing cap. Determine the amount of
clearance by measuring the width of the compressed
Plastigage with the scale on the Plastigage envelope
(Fig. 43). (Refer to 9 - ENGINE - SPECIFICATIONS)
for the proper clearance.
Plastigage should indicate the same clearance
across the entire width of the insert. If clearance var-
ies, it may indicate a tapered journal or foreign
material trapped behind the insert.
If the specified clearance is indicated and there are
no abnormal wear patterns, replacement of the bear-
ing inserts is not necessary. Remove the Plastigage
from the crankshaft journal and bearing insert. Pro-
ceed to (Refer to 9 - ENGINE/ENGINE BLOCK/
CRANKSHAFT MAIN BEARINGS -
INSTALLATION).
If the clearance exceeds specification, install a pair
of 0.025 mm (0.001 inch) undersize bearing inserts
and measure the clearance as described in the previ-
ous steps.
The clearance indicate with the 0.025 mm (0.001
inch) undersize insert pair installed will determine if
this insert size or some other combination will pro-
vide the specified clearance.FOR EXAMPLE:If the
clearance was 0.0762 mm (0.003 inch) originally, a
pair of 0.0254 mm (0.001 inch) undersize inserts
would reduce the clearance by 0.0254 mm (0.001
inch). The clearance would then be 0.0508 mm (0.002
inch) and within the specification. A 0.051 mm (0.002
inch) undersize bearing insert and a 0.0254 mm
(0.001 inch) undersize insert would reduce the origi-
Fig. 41 Crankshaft with Select Fit Marking Location
1 - 1/4º LETTERS
2 - (ROD)
3 - (MAIN)
9 - 36 ENGINE - 4.0LWJ
CRANKSHAFT (Continued)