Jeep XJ. Manual — part 311
INSTALLATION
(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.
(3) Fill the oil pan with oil to the specified level.
TIMING CASE COVER OIL SEAL
This procedure is done with the timing case cover
installed.
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove the serpentine drive belt.
(3) Remove the vibration damper.
(4) Remove the radiator shroud.
(5) Carefully remove the oil seal. Make sure seal
bore is clean.
INSTALLATION
(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. 83). 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 Mopar Silicone Rubber Adhesive Sealant
to the keyway in the crankshaft and insert the key.
With the key inserted in the keyway in the crank-
shaft, install the vibration damper, washer and bolt.
Lubricate and tighten the bolt to 108 N·m (80 ft. lbs.)
torque.
(5) Install the serpentine belt and tighten to the
specified tension (refer to Group 7, Cooling Systems
for the proper specifications and procedures).
(6) Install the radiator shroud.
(7) Connect negative cable to battery.
DISASSEMBLY AND ASSEMBLY
CYLINDER BLOCK
DISASSEMBLY
Refer
to
the
applicable
sections
for
detailed
instructions.
(1) Drain the engine oil. Remove and discard the
oil filter.
(2) Remove the water pump from the cylinder
block.
(3) Remove the vibration damper.
(4) Remove the timing case cover and lay the cover
upside down.
(5) Position a drift punch into the slot in the back
of the cover and tap the old seal out.
(6) Remove the oil slinger from crankshaft.
(7) Remove
the
camshaft
retaining
bolt
and
remove the sprockets and chain as an assembly.
(8) Remove the camshaft.
(9) Remove the oil pan and gasket.
(10) Remove the front and rear oil galley plugs.
(11) Remove the oil pump.
(12) Remove the connecting rods and the pistons.
Remove the connecting rod and piston assemblies
through the top of the cylinder bores.
(13) Remove the crankshaft.
ASSEMBLY
Refer
to
the
applicable
sections
for
detailed
instructions.
(1) Install the crankshaft.
(2) Install the connecting rods and the pistons
through the top of the cylinder bores.
(3) Install the oil pump.
(4) Install the oil pan and gasket.
(5) Install the camshaft.
(6) Install the sprockets and chain as an assembly.
(7) Install the oil slinger from the crankshaft.
(8) Install the timing case cover seal.
(9) Install the timing case cover.
(10) Install the vibration damper.
(11) Install the water pump. Tighten the mounting
bolts to 31 N·m (23 ft. lbs.) torque.
Fig. 83 Timing Case Cover Oil Seal Installation
1 – SEAL INSTALLATION TOOL
2 – DRAW SCREW TOOL
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4.0L ENGINE
XJ
REMOVAL AND INSTALLATION (Continued)
(12) Lubricate the oil filter seal with clean engine
oil. Tighten oil filter to 18 N·m (156 in. lbs.) torque.
(13) Install the engine into the vehicle.
(14) Fill the engine with clean lubrication oil (refer
to Group 0, Lubrication and Maintenance).
(15) Fill the cooling system.
CLEANING AND INSPECTION
CYLINDER HEAD
CLEANING
Thoroughly clean the engine cylinder head and cyl-
inder block mating surfaces. Clean the intake and
engine exhaust manifold and engine cylinder head
mating surfaces. Remove all gasket material and car-
bon.
Check to ensure that no coolant or foreign material
has fallen into the tappet bore area.
Remove the carbon deposits from the combustion
chambers and top of the pistons.
INSPECTION
Use a straightedge and feeler gauge to check the
flatness of the engine cylinder head and block mating
surfaces.
CYLINDER HEAD COVER
CLEANING
Remove any original sealer from the cover sealing
surface of the engine cylinder head and clean the
surface using a fabric cleaner.
Remove all residue from the sealing surface using
a clean, dry cloth.
INSPECTION
Inspect the engine cylinder head cover for cracks.
Replace the cover, if cracked.
The original dark grey gasket material should
NOT be removed. If sections of the gasket material
are missing or are compressed, replace the engine
cylinder head cover. However, sections with minor
damage such as small cracks, cuts or chips may be
repaired with a hand held applicator. The new mate-
rial must be smoothed over to maintain gasket
height. Allow the gasket material to cure prior to
engine cylinder head cover installation.
ROCKER ARMS AND PUSH RODS
CLEANING
Clean all the components with cleaning solvent.
Use compressed air to blow out the oil passages in
the rocker arms and push rods.
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.
HYDRAULIC TAPPETS
CLEANING
Clean each tappet assembly in cleaning solvent to
remove all varnish, gum and sludge deposits.
INSPECTION
Inspect for indications of scuffing on the side and
base of each tappet body.
Inspect each tappet base for concave wear with a
straightedge positioned across the base. If the base is
concave, the corresponding lobe on the camshaft is
also worn. Replace the camshaft and defective tap-
pets.
After cleaning and inspection, test each tappet for
specified leak-down rate tolerance to ensure zero-lash
operation (Fig. 84).
Swing the weighted arm of the hydraulic valve tap-
pet tester away from the ram of the Leak-Down
Tester.
(1) Place a 7.925-7.950 mm (0.312-0.313 inch)
diameter ball bearing on the plunger cap of the tap-
pet.
(2) Lift the ram and position the tappet (with the
ball bearing) inside the tester cup.
(3) Lower the ram, then adjust the nose of the ram
until it contacts the ball bearing. DO NOT tighten
the hex nut on the ram.
(4) Fill the tester cup with hydraulic valve tappet
test oil until the tappet is completely submerged.
(5) Swing the weighted arm onto the push rod and
pump the tappet plunger up and down to remove air.
When the air bubbles cease, swing the weighted arm
away and allow the plunger to rise to the normal
position.
(6) Adjust the nose of the ram to align the pointer
with the SET mark on the scale of the tester and
tighten the hex nut.
XJ
4.0L ENGINE
9 - 113
DISASSEMBLY AND ASSEMBLY (Continued)
(7) Slowly swing the weighted arm onto the push
rod.
(8) Rotate the cup by turning the handle at the
base of the tester clockwise one revolution every 2
seconds.
(9) Observe the leak-down time interval from the
instant the pointer aligns with the START mark on
the scale until the pointer aligns with the 0.125
mark. A normally functioning tappet will require
20-110 seconds to leak-down. Discard tappets with
leak-down time interval not within this specification.
CYLINDER BLOCK
CLEANING
Thoroughly clean the oil pan and engine block gas-
ket surfaces.
Use compressed air to clean out:
• The galley at the oil filter adaptor hole.
• The front and rear oil galley holes.
• The 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. 85). 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 90° 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.
Fig. 84 Leak-Down Tester
1 – POINTER
2 – WEIGHTED ARM
3 – RAM
4 – CUP
5 – HANDLE
6 – PUSH ROD
Fig. 85 Cylinder Bore Measurement
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4.0L ENGINE
XJ
CLEANING AND INSPECTION (Continued)
SPECIFICATIONS
SPECIFICATIONS
4.0L ENGINE
DESCRIPTION
SPECIFICATION
Engine Type
In-line 6 Cylinder
Bore and Stroke
98.4 x 86.69 mm
(3.88 x 3.413 in.)
Displacement
4.0L (242 cu. in.)
Compression Ratio
8.8:1
Firing Order
1–5–3–6–2–4
Lubrication
Pressure Feed–Full Flow
Filtration
Cooling System
Liquid Cooled–Forced
Circulation
Cylinder Block
Cast Iron
Crankshaft
Cast Nodular Iron
Cylinder Head
Cast Iron
Camshaft
Cast Iron
Pistons
Aluminum Alloy
Combustion Chamber
Dual-Quench
Connecting Rods
Cast Malleable Iron
CAMSHAFT
Hydraulic Tappet
Clearance
Zero Lash
Bearing Clearance
0.025 to 0.076 mm
(0.001 to 0.003 in.)
Bearing Journal Diameter
No. 1
51.54 to 51.56 mm
(2.029 to 2.030 in.)
No. 2
51.28 to 51.31 mm
(2.019 to 2.020 in.)
No. 3
51.03 to 51.05 mm
(2.009 to 2.010 in.)
No. 4
50.78 to 50.80 mm
(1.999 to 2.000 in.)
DESCRIPTION
SPECIFICATION
Base Circle Runout
(MAX)
0.03 mm
(0.001 in.)
Valve Lift
Intake
10.350 mm (0.4075 in.)
Exhaust
10.528 mm (0.4145 in.)
Valve Timing
Intake
Opens
12.4° BTDC
Closes
60.9° ABDC
Exhaust
Opens
49.8 BBDC
Closes
29.2° ATDC
Valve Overlap
41.6°
Intake Duration
253.3°
Exhaust Duration
259.°
CRANKSHAFT
End Play
0.038 to 0.165 mm
(0.0015 to 0.0065 in.)
Main Bearing Journal
Diameter
No. 1-6
63.489 to 63.502 mm
(2.4996 to 2.5001 in.)
No. 7
63.449 to 63.487 mm
(2.4980 to 2.4995 in.)
Main Bearing Journal
Width
No. 1
27.58 to 27.89 mm
(1.086 to 1.098 in.)
No. 3
32.28 to 32.33 mm
(1.271 to 1.273 in.)
No. 2-4-5-6-7
30.02 to 30.18 mm
(1.182 to 1.188 in.)
Main Bearing Clearance
0.03 to 0.06 mm
(0.001 to 0.0025 in.)
Preferred
0.051 mm (0.002 in.)
XJ
4.0L ENGINE
9 - 115
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