8W-12 JUNCTION BLOCK
Component PageA/C Compressor Clutch Relay................8W-12-18
Accessory Delay Relay.....................8W-12-25
Adjustable Pedals Module..................8W-12-11
Airbag Control Module....................8W-12-25
Auto Shut Down Relay....................8W-12-18
Automatic Day/Night Mirror.................8W-12-23
Automatic Headlamp Light Sensor/VTSS LED......8W-12-15
Automatic Zone Control Module..........8W-12-15, 17, 22
Back-Up Lamp Relay.....................8W-12-22
Body Control Module . . . 8W-12-10, 12, 13, 15, 17, 20, 23, 24, 25,
26, 27, 28, 29, 30, 31, 35, 36
Brake Lamp Switch......................8W-12-24
Cargo Lamp......................8W-12-16, 24, 27
Cigar Lighter..........................8W-12-17
Cigar Lighter Relay....................8W-12-17, 26
Circuit Breaker No. 1...................8W-12-28, 29
Circuit Breaker No. 2......................8W-12-9
Clockspring...........................8W-12-31
Combination Flasher............8W-12-10, 22, 27, 32, 35
Controller Antilock Brake..................8W-12-21
Data Link Connector.....................8W-12-10
Driver Door Module......................8W-12-34
Driver Heated Seat Switch..................8W-12-22
Driver Lumbar Switch.....................8W-12-9
Driver Power Seat Switch...................8W-12-9
Electric Brake..........................8W-12-21
Engine Control Module....................8W-12-19
Engine Starter Motor Relay.................8W-12-26
EVAP/Purge Solenoid.....................8W-12-18
Fog Lamp Relay........................8W-12-24
Front Power Outlet......................8W-12-11
Front Wiper Motor....................8W-12-28, 29
Fuel Pump Relay........................8W-12-18
Fuse 2..............................8W-12-17
Fuse 3............................8W-12-10, 20
Fuse 4..............................8W-12-10
Fuse 5..............................8W-12-11
Fuse 6............................8W-12-12, 13
Fuse 7..............................8W-12-15
Fuse 8..............................8W-12-16
Fuse 9..............................8W-12-11
Fuse 10..............................8W-12-11
Fuse 11..............................8W-12-17
Fuse 12.......................8W-12-18, 19, 21, 34
Fuse 14..............................8W-12-20
Fuse 15.........................8W-12-11, 15, 20
Fuse 16..............................8W-12-10
Fuse 17..............................8W-12-10
Fuse 18...........................8W-12-21, 34
Fuse 19..............................8W-12-21
Fuse 20..............................8W-12-22
Fuse 21...........................8W-12-18, 19
Fuse 22..............................8W-12-23
Fuse 23..............................8W-12-24
Fuse 24..............................8W-12-24
Fuse 25..............................8W-12-25
Fuse 26..............................8W-12-17
Fuse 27..............................8W-12-36
Fuse 28..............................8W-12-26
Fuse 29..............................8W-12-26
Fuse 30..............................8W-12-26
Fuse 31..............................8W-12-26
Fuse 32..............................8W-12-25
Fuse 33..............................8W-12-25
G200...............................8W-12-35
Glove Box Lamp........................8W-12-16
Headlamp Leveling Switch...............8W-12-12, 13
High Beam Relay........................8W-12-10
Horn Relay...........................8W-12-31
Horn Switch...........................8W-12-31
Instrument Cluster..................8W-12-10, 23, 32
Intrusion Transceiver Module................8W-12-16
Junction Block.........8W-12-2, 3, 9, 10, 11, 12, 13, 15, 16,
17, 18, 19, 20, 21, 22, 23, 24, 25,
26, 27, 28, 29, 30, 31, 32, 34, 35, 36Component PageLeft Courtesy Lamp......................8W-12-16
Left Door Handle Courtesy Lamp.........8W-12-16, 24, 30
Left Fog Lamp.........................8W-12-24
Left Front Park Lamp.....................8W-12-14
Left Front Park/Turn Signal Lamp...........8W-12-14, 33
Left Front Side Marker Lamp..............8W-12-14, 33
Left Front Turn Signal Lamp................8W-12-33
Left Headlamp Leveling Motor...............8W-12-14
Left High Beam Headlamp..................8W-12-10
Left Liftgate Ajar Switch...................8W-12-30
Left Low Beam Headlamp..................8W-12-20
Left Multi-Function Switch...............8W-12-10, 35
Left Rear Door Lock Motor/Ajar Switch..........8W-12-27
Left Rear Lamp Assembly...........8W-12-12, 13, 27, 36
Left Side Repeater Lamp...................8W-12-32
Left Visor/Vanity Lamp..................8W-12-16, 30
License Lamp No. 1....................8W-12-12, 13
License Lamp No. 2....................8W-12-12, 13
Liftgate Flip-Up Ajar Switch.................8W-12-30
Liftgate Flip-Up Push Button Switch...........8W-12-16
Liftgate Power Lock Motor..................8W-12-16
Low Beam Relay........................8W-12-20
Low Beam/Daytime Running Lamp Relay.........8W-12-20
Manual Temperature Control..............8W-12-17, 22
Overhead Map/Courtesy Lamp...........8W-12-16, 24, 30
Park Lamp Relay.....................8W-12-12, 13
Park/Neutral Position Switch................8W-12-22
Passenger Door Module....................8W-12-34
Passenger Heated Seat Switch...............8W-12-22
Passenger Lumbar Switch...................8W-12-9
Passenger Power Seat Switch.................8W-12-9
Power Amplifier.........................8W-12-11
Power Connector........................8W-12-11
Power Distribution Center....8W-12-10, 11, 15, 17, 20, 21, 34
Powertrain Control Module.................8W-12-18
Radio.............................8W-12-11, 26
Rain Sensor...........................8W-12-25
Rear Window Defogger....................8W-12-17
Rear Window Defogger Relay................8W-12-17
Rear Wiper Motor.....................8W-12-16, 30
Remote Keyless Module....................8W-12-15
Right Courtesy Lamp.....................8W-12-16
Right Door Handle Courtesy Lamp........8W-12-16, 24, 30
Right Fog Lamp........................8W-12-24
Right Front Park Lamp....................8W-12-14
Right Front Park/Turn Signal Lamp..........8W-12-14, 33
Right Front Side Marker Lamp.............8W-12-14, 33
Right Front Turn Signal Lamp...............8W-12-33
Right Headlamp Leveling Motor..............8W-12-14
Right High Beam Headlamp.................8W-12-10
Right Liftgate Ajar Switch..................8W-12-30
Right Low Beam Headlamp.................8W-12-20
Right Multi-Function Switch.................8W-12-26
Right Rear Lamp Assembly..........8W-12-12, 13, 32, 36
Right Side Repeater Lamp..................8W-12-32
Right Visor/Vanity Lamp.................8W-12-16, 30
Seat Module...........................8W-12-9
Sentry Key Immobilizer Module............8W-12-15, 23
Shifter Assembly......................8W-12-18, 19
Siren...............................8W-12-15
Sunroof Control Module....................8W-12-25
Temperature Valve Actuator.................8W-12-22
Trailer Tow Brake Lamp Relay...............8W-12-21
Trailer Tow Circuit Breaker.................8W-12-17
Trailer Tow Connector.....................8W-12-12
Trailer Tow Left Turn Relay.................8W-12-27
Trailer Tow Right Turn Relay................8W-12-32
Transmission Control Module..............8W-12-18, 26
Transmission Solenoid/TRS Assembly...........8W-12-22
Underhood Lamp........................8W-12-15
Vehicle Information Center...............8W-12-16, 23
Wiper High/Low Relay..................8W-12-28, 29
Wiper On/Off Relay....................8W-12-28, 29
WJ8W-12 JUNCTION BLOCK 8W - 12 - 1
ENGINE
TABLE OF CONTENTS
page page
ENGINE - 4.0L............................ 1ENGINE - 4.7L........................... 61
ENGINE - 4.0L
TABLE OF CONTENTS
page page
ENGINE - 4.0L
DESCRIPTION..........................2
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - INTRODUCTION............3
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - PERFORMANCE............4
DIAGNOSIS AND TESTINGÐ ENGINE
DIAGNOSIS - MECHANICAL..............6
DIAGNOSIS AND TESTINGÐCYLINDER
COMPRESSION PRESSURE..............8
DIAGNOSIS AND TESTING - CYLINDER
COMBUSTION PRESSURE LEAKAGE.......8
DIAGNOSIS AND TESTINGÐREAR SEAL
AREA LEAKS..........................9
STANDARD PROCEDURE
STANDARD PROCEDURE - FORM-IN-
PLACE GASKETS AND SEALERS..........9
STANDARD PROCEDURE - REPAIR
DAMAGED OR WORN THREADS.........10
STANDARD PROCEDUREÐHYDROSTATIC
LOCK...............................10
STANDARD PROCEDURE - CYLINDER
BORE HONING.......................10
STANDARD PROCEDURE - ENGINE CORE
AND OIL GALLERY PLUGS..............11
REMOVAL.............................11
INSTALLATION.........................13
SPECIFICATIONS
ENGINE - 4.0L........................14
TORQUE - 4.0L ENGINE................17
AIR CLEANER ELEMENT
REMOVAL - 4.0L........................18
INSTALLATION - 4.0L....................19
AIR CLEANER HOUSING
REMOVAL - 4.0L........................19
INSTALLATION - 4.0L....................19CYLINDER HEAD
DESCRIPTION.........................19
REMOVAL.............................19
CLEANING............................21
INSPECTION..........................21
INSTALLATION.........................21
CYLINDER HEAD COVER(S)
DESCRIPTION.........................22
REMOVAL.............................22
CLEANING............................23
INSPECTION..........................23
INSTALLATION.........................23
INTAKE/EXHAUST VALVES & SEATS
DESCRIPTION.........................23
STANDARD PROCEDURE - VALVE SERVICE . . 23
REMOVAL.............................25
INSTALLATION.........................25
ROCKER ARM / ADJUSTER ASSEMBLY
DESCRIPTION.........................26
OPERATION...........................26
REMOVAL.............................26
CLEANING............................26
INSPECTION..........................27
INSTALLATION.........................27
VALVE STEM SEALS
DESCRIPTION.........................27
VALVE SPRINGS
DESCRIPTION.........................28
STANDARD PROCEDURE - VALVE SPRING
TENSION TEST.......................28
REMOVAL.............................28
INSTALLATION.........................29
ENGINE BLOCK
CLEANING............................30
INSPECTION..........................30
CAMSHAFT & BEARINGS
DESCRIPTION.........................30
WJENGINE 9 - 1
DESCRIPTION SPECIFICATION
Valve Stem-to-Guide 0.025 to 0.076 mm
Clearance (0.001 to 0.003 in.)
Valve Seat Angle
Intake 44.5É
Exhaust 44.5É
Valve Seat Width 1.02 to 1.52 mm
(0.040 to 0.060 in.)
Valve Seat Runout 0.064 mm (0.0025 in.)
Flatness 0.03 mm per 25 mm
(0.001 in. per 1 in.)
0.05 mm per 152 mm
(0.002 in. per 6 in.)
Flatness Max. 0.20 mm - max. for total
length
(0.008 in. max. for total
length)
ROCKER ARMS, PUSH RODS & TAPPETS
Rocker Arm Ratio 1.6:1
Push Rod Length 244.856 to 245.364 mm
(Pink) (9.640 to 9.660 in.)
Push Rod Diameter 7.92 to 8.00 mm
(0.312 to 0.315 in.)
Hydraulic Tappet
Diameter22.962 to 22.974 mm
(0.904 to 0.9045 in.)
Tappet-to-Bore Clearance 0.025 to 0.063 mm
(0.001 to 0.0025 in.)
VA LV E S
Valve Length (Overall)
Intake 122.479 to 122.860 mm
(4.822 to 4.837 in.)
Exhaust 122.860 to 123.241 mm
(4.837 to 4.852 in.)
Valve Stem Diameter 7.899 to 7.925 mm
(0.311 to 0.312 in.)
Stem-to-Guide Clearance 0.025 to 0.076 mm
(0.001 to 0.003 in.)DESCRIPTION SPECIFICATION
Valve Head Diameter
Intake 48.387 to 48.641 mm
(1.905 to 1.915 in.)
Exhaust 37.973 to 38.227 mm
(1.495 to 1.505 in.)
Valve Face Angle
Intake 46.5É
Exhaust 46.5É
Tip Refinishing (Max.
Allowable)0.25 mm (0.010 in.)
VALVE SPRINGS
Free Length (Approx.) 47.65 mm (1.876 in.)
Spring Load
Valve Closed 316 to 351 N @ 41.656
mm
(71 to 79 lbf. @ 1.64 in.)
Valve Open 898.6 to 969.7 N @
30.89 mm
(202 to 218 lbf @ 1.216
in.)
Inside Diameter 21.0 mm to 21.51 mm
(0.827 to 0.847 in.)
Installed Height 41.656 mm (1.64 in.)
PISTONS
Weight (Less Pin) 417 to 429 grams
(14.7 to 15.1 oz.)
Piston Pin Bore
(Centerline40.61 to 40.72 mm
to Piston Top) (1.599 to 1.603 in.)
Piston-to-Bore Clearance 0.018 to 0.038 mm
(0.0008 to 0.0015 in.)
Ring Gap Clearance
Top Compression Ring 0.229 to 0.610 mm
(0.0090 to 0.0240 in.)
2nd Compression Ring 0.483 to 0.965 mm
(0.0190 to 0.0380 in.)
Oil Control Steel Rails 0.254 to 1.500 mm
(0.010 to 0.060 in.)
9 - 16 ENGINE - 4.0LWJ
ENGINE - 4.0L (Continued)
(2) Lift cover up and position to the side.
(3) Remove air cleaner element.
INSTALLATION - 4.0L
(1) Clean inside of air cleaner housing before
installing new element.
(2) Install air cleaner element into housing.
(3) Latch clips and clamp cover down to secure. Be
sure air cleaner cover is properly seated to air
cleaner housing.
AIR CLEANER HOUSING
REMOVAL - 4.0L
(1) Disconnect air cleaner cover-to-air duct clamp
(Fig. 6).
(2) Disconnect air duct at housing.
(3)Each of the 3 air cleaner housing mount-
ing bolts is attached with 2 nuts (an upper nut
and lower nut). DO NOT REMOVE BOLTS. To
prevent stripping bolts, only remove lower
nuts. The lower housing nuts are located under
left front inner fender (Fig. 6).
(a) To gain access to lower nuts, raise vehicle.
(b) Remove clips retaining rubber inner fender
shield.
(c) Pry back shield enough to gain access to
lower nuts.
(d) Remove 3 nuts.
(e) Remove air cleaner assembly from vehicle.
(4) If resonator is to be removed, disconnect
breather tube at resonator, disconnect air duct clamp
at resonator (Fig. 6)and remove 1 resonator mount-
ing bolt. Remove resonator from throttle body by
loosening clamp (Fig. 7).
INSTALLATION - 4.0L
(1) Position air cleaner assembly to body and
install 3 nuts. Tighten nuts to 10 N´m (93 in. lbs.)
torque.To prevent excessive vibration transmit-
ted through housing, the nuts must be properly
torqued. Do not overtighten nuts.
(2) If resonator was removed: Install resonator and
bolts. Tighten bolts to 4 N´m (35 in. lbs.) torque.
Tighten clamp at throttle body to 4 N´m (35 in. lbs.)
torque.
(3) Position fender liner and install clips.
(4) Connect air duct at housing (Fig. 6).
(5) Tighten air duct clamp.
CYLINDER HEAD
DESCRIPTION
The cylinder head is made of cast iron containing
twelve valves made of chrome plated heat resistant
steel, valve stem seals, springs, retainers and keep-
ers. The cylinder head and valve seats can be resur-
faced for service purposes.
The valve guides are integral to the cylinder head,
They are not replaceable. However, they are service-
able.
The cylinder head uses dual quench-type design
combustion chambers which cause turbulence in the
cylinders allowing faster burning of the air/fuel mix-
ture, resulting in better fuel economy (Fig. 8).
REMOVAL
NOTE: This procedure can be done with the engine
in or out of the vehicle.
(1) Disconnect the battery negative cable.
WARNING: DO NOT REMOVE THE CYLINDER
BLOCK DRAIN PLUGS OR LOOSEN THE RADIATOR
DRAIN COCK WITH THE SYSTEM HOT AND PRES-
SURIZED BECAUSE SERIOUS BURNS FROM THE
COOLANT CAN OCCUR.
Fig. 7 RESONATOR CLAMP - 4.0L
1 - RESONATOR
2 - AIR DUCT
3 - CLAMP
WJENGINE - 4.0L 9 - 19
AIR CLEANER ELEMENT (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)
(3) Control valve seat runout to a maximum of
0.0635 mm (0.0025 in.) (Fig. 16).
VALVE STEM-TO-GUIDE CLEARANCE
MEASUREMENT
PREFERRED METHOD
(1) Remove the valve from the head.
(2) Clean the valve stem guide bore with solvent
and a bristle brush.
(3) Insert a telescoping gauge into the valve stem
guide bore approximately 9.525 mm (.375 inch) from
the valve spring side of the head (Fig. 17).
(4) Remove and measure telescoping gauge with a
micrometer.
(5) Repeat the measurement with contacts length-
wise to engine cylinder head.
(6) Compare the crosswise to lengthwise measure-
ments to determine out-of-roundness. If the measure-
ments differ by more than 0.0635 mm (0.0025 in.),
ream the guide bore to accommodate an oversize
valve stem.
(7) Compare the measured valve guide bore diam-
eter with specifications (7.95-7.97 mm or 0.313-0.314
inch). If the measurement differs from specification
by more than 0.076 mm (0.003 inch), ream the guide
bore to accommodate an oversize valve stem.
ALTERNATIVE METHOD
(1) Use a dial indicator to measure the lateral
movement of the valve stem (stem-to-guide clear-
ance). This must be done with the valve installed in
its guide and just off the valve seat (Fig. 18).
(2) Correct clearance is 0.025-0.0762 mm
(0.001-0.003 inch). If indicated movement exceeds the
specification ream the valve guide to accommodate
an oversize valve stem.
Fig. 14 VALVE AND KEEPER CONFIGURATION 4.0L
1 - VALVE LOCKS (3±BEAD)
2 - RETAINER
3 - VALVE STEM OIL SEAL
4 - INTAKE VALVE
5 - EXHAUST VALVE
6 - VALVE SPRING
Fig. 15 Valve Facing
1 - VALVE MARGIN
2 - NO MARGIN
Fig. 16 Measurement of Valve Seat Runout
1 - DIAL INDICATOR
9 - 24 ENGINE - 4.0LWJ
INTAKE/EXHAUST VALVES & SEATS (Continued)
NOTE: Valve seats must be ground after reaming
the valve guides to ensure that the valve seat is
concentric to the valve guide.
REMOVAL
NOTE: This procedure is done with the engine cyl-
inder head removed from the block.(1) Remove the engine cylinder head (Refer to 9 -
ENGINE/CYLINDER HEAD - REMOVAL) from the
cylinder block.
(2) Use Valve Spring Compressor Tool
MD-998772A and compress each valve spring.
(3) Remove the valve locks, retainers, springs and
valve stem oil seals. Discard the oil seals (Fig. 19).
(4) Use a smooth stone or a jewelers file to remove
any burrs on the top of the valve stem, especially
around the groove for the locks.
(5) Remove the valves, and place them in a rack in
the same order as removed.
INSTALLATION
NOTE: This procedure is done with the engine cyl-
inder head removed from the block.
(1) Thoroughly clean the valve stems and the valve
guide bores.
(2) Lightly lubricate the stem.
(3) Install the valve in the original valve guide
bore.
(4) Install the replacement valve stem oil seals on
the valve stems (Fig. 20). If the 0.381 mm (0.015
inch) oversize valve stems are used, oversize oil seals
are required.
Fig. 17 Measurement of Valve Guide Bore Diameter
1 - GAUGE
2 - 9.525 MM (3/8 INCH)
3 - VALVE STEM GUIDE
4 - CYLINDER HEAD
Fig. 18 Measurement of Lateral Movement Of Valve
Stem
1 - DIAL INDICATOR
Fig. 19 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
WJENGINE - 4.0L 9 - 25
INTAKE/EXHAUST VALVES & SEATS (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)