Jeep Wrangler TJ. Manual — part 446
NOTE: It is not advisable to attempt to replace cam-
shaft bearings unless special removal and installa-
tion tools are available, such as recommended tool
8544 Camshaft Bushing Remover Installer.
(2) Using Special tool 8544 Camshaft Bushing
Remover Installer, remove the camshaft bearings.
REMOVAL - CAMSHAFT
WARNING: THE COOLANT IN A RECENTLY OPER-
ATED
ENGINE
IS
HOT
AND
PRESSURIZED.
RELEASE THE PRESSURE BEFORE REMOVING
THE DRAIN COCK, CAP AND DRAIN PLUGS.
(1) Disconnect negative cable from battery.
(2) Drain the cooling system (Refer to 7 - COOL-
ING - STANDARD PROCEDURE).
(3) Remove the radiator (Refer to 7 - COOLING/
ENGINE/RADIATOR - REMOVAL) and condenser
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING/A/C
CONDENSER
-
REMOVAL),
if
equipped with A/C.
(4) Remove the engine cylinder head cover (Refer
to
9
-
ENGINE/CYLINDER
HEAD/CYLINDER
HEAD COVER(S) - REMOVAL).
(5) Remove the rocker arms, bridges and pivots
(Refer to 9 - ENGINE/CYLINDER HEAD/ROCKER
ARM / ADJUSTER ASSY - REMOVAL).
(6) Remove the push rods.
(7) Remove the engine cylinder head and gasket
(Refer
to
9
-
ENGINE/CYLINDER
HEAD
-
REMOVAL).
(8) Remove the hydraulic valve tappets from the
engine cylinder block (Refer to 9 - ENGINE/ENGINE
BLOCK/HYDRAULIC LIFTERS (CAM IN BLOCK) -
REMOVAL).
(9) Remove the vibration damper (Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
REMOVAL).
(10) Remove the timing case cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - REMOVAL).
(11) Rotate the crankshaft until the crankshaft
sprocket timing mark is aligned on centerline with
the camshaft sprocket timing mark (Fig. 33).
(12) Remove the timing chain and sprockets (Refer
to 9 - ENGINE/VALVE TIMING/TIMING BELT/
CHAIN AND SPROCKETS - REMOVAL).
(13) Remove the front bumper and/or grille, as
required.
(14) Remove the two thrust plate retaining screws,
thrust plate and camshaft (Fig. 32).
Fig. 32 Camshaft Removal
1 - CAMSHAFT
2 - CRANKSHAFT
Fig. 33 Crankshaft / Camshaft Sprocket Timing Mark
Alignment
1 - CAMSHAFT SPROCKET
2 - TIMING MARKS
3 - CRANKSHAFT SPROCKET
TJ
ENGINE 4.0L
9 - 99
CAMSHAFT & BEARINGS (IN BLOCK) (Continued)
INSTALLATION
INSTALLATION - CAMSHAFT BEARINGS
CAUTION: Make sure outside diameter of number 1
bearing is clean. Make sure that the bearing is
properly installed in the engine block, align the oil
hole in the bearing with the oil gallery in the bear-
ing bore. Failure to do so will cause inadequate oil
supply for the sprockets and timing chain.
(1) Using recommended special tool 8544 Cam-
shaft Bearing Remover/Installer, install new cam-
shaft bearings.
INSTALLATION - CAMSHAFT
(1) Lubricate the camshaft with Mopar
t Engine
Oil Supplement, or equivalent.
(2) Carefully install the camshaft to prevent dam-
age to the camshaft bearings.
(3) Position thrust plate and install retaining
screws. Tighten screws to 24 N·m (18 ft. lbs.).
(4) Lubricate the camshaft with Mopar
t engine oil
supplement, or equivalent.
(5) Install
the
camshaft
sprocket,
crankshaft
sprocket and timing chain (Refer to 9 - ENGINE/
VALVE
TIMING/TIMING
BELT/CHAIN
AND
SPROCKETS - INSTALLATION).
(6) Tighten the camshaft sprocket bolt and washer
to 68 N·m (50 ft. lbs.).
(7) To verify correct installation of the timing
chain, turn the crankshaft two full revolutions then
position the camshaft sprocket timing mark as shown
in (Fig. 34).
(8) Install the timing case cover with a replace-
ment oil seal (Fig. 35). (Refer to 9 - ENGINE/VALVE
TIMING/TIMING
BELT
/
CHAIN
COVER(S)
-
INSTALLATION).
(9) Install the vibration damper (Fig. 35) (Refer to
9
-
ENGINE/ENGINE
BLOCK/VIBRATION
DAMPER - INSTALLATION).
(10) Install the hydraulic valve tappets (Refer to 9
- ENGINE/ENGINE BLOCK/HYDRAULIC LIFTERS
(CAM IN BLOCK) - INSTALLATION).
(11) Install the cylinder head gasket with the
numbers facing up.
(12) Install
the
cylinder
head
(Refer
to
9
-
ENGINE/CYLINDER HEAD - INSTALLATION).
(13) Install the push rods.
(14) Install the rocker arms and pivot and bridge
assemblies (Refer to 9 - ENGINE/CYLINDER HEAD/
ROCKER ARM / ADJUSTER ASSY - INSTALLA-
TION).
(15) Install the engine cylinder head cover (Refer
to
9
-
ENGINE/CYLINDER
HEAD/CYLINDER
HEAD COVER(S) - INSTALLATION).
(16) Install the serpentine drive belt (Refer to 7 -
COOLING/ACCESSORY
DRIVE/DRIVE
BELTS
-
INSTALLATION).
Fig. 34 Crankshaft / Camshaft Chain Drive
Installation—Typical
1 - CAMSHAFT SPROCKET
2 - TIMING MARKS
3 - CRANKSHAFT SPROCKET
Fig. 35 Timing Case Cover Components
1 - TIMING CASE COVER
2 - OIL SLINGER
3 - CRANKSHAFT OIL SEAL
4 - VIBRATION DAMPER PULLEY
9 - 100
ENGINE 4.0L
TJ
CAMSHAFT & BEARINGS (IN BLOCK) (Continued)
NOTE: During installation, lubricate the hydraulic
valve
tappets
and
all
valve
components
with
Mopar
T
Engine Oil Supplement, or equivalent. The
Mopar
T
Engine Oil Supplement, or equivalent must
remain with the engine oil for at least 1609 km
(1,000 miles). The oil supplement need not be
drained until the next scheduled oil change.
(17) Install the radiator (Refer to 7 - COOLING/
ENGINE/RADIATOR - INSTALLATION).
(18) Check the ignition timing and adjust as nec-
essary.
(19) Install the grille and bumper, if removed.
(20) Connect negative cable to battery.
CONNECTING ROD BEARINGS
STANDARD PROCEDURE - FITTING
CONNECTING ROD BEARINGS
Inspect the connecting rod bearings for scoring and
bent alignment tabs (Fig. 36) (Fig. 37). Check the
bearings for normal wear patterns, scoring, grooving,
fatigue and pitting (Fig. 38). Replace any bearing
that shows abnormal wear.
Inspect the connecting rod journals for signs of
scoring, nicks and burrs.
Misaligned or bent connecting rods can cause
abnormal wear on pistons, piston rings, cylinder
walls, connecting rod bearings and crankshaft con-
necting rod journals. If wear patterns or damage to
any of these components indicate the probability of a
misaligned connecting rod, inspect it for correct rod
alignment. Replace misaligned, bent or twisted con-
necting rods.
BEARING-TO-JOURNAL CLEARANCE
(1) Wipe the oil from the connecting rod journal.
(2) Use short rubber hose sections over rod bolts
during installation.
(3) Lubricate the upper bearing insert and install
in connecting rod.
(4) Use piston ring compressor to install the rod
and piston assemblies. The oil squirt holes in the
rods must face the camshaft. The arrow on the piston
crown should point to the front of the engine (Fig.
39). Verify that the oil squirt holes in the rods face
the camshaft and that the arrows on the pistons face
the front of the engine.
(5) Install the lower bearing insert in the bearing
cap. The lower insert must be dry. Place strip of Plas-
tigage across full width of the lower insert at the cen-
ter of bearing cap. Plastigage must not crumble in
use. If brittle, obtain fresh stock.
(6) Install bearing cap and connecting rod on the
journal and tighten nuts to 45 N·m (33 ft. lbs.)
torque. DO NOT rotate crankshaft. Plastigage will
smear, resulting in inaccurate indication.
Fig. 36 Connecting Rod Bearing Inspection
1 - UPPER BEARING HALF
2 - MATING EDGES
3 - GROOVES CAUSED BY ROD BOLTS SCRATCHING JOURNAL
DURING INSTALLATION
4 - WEAR PATTERN - ALWAYS GREATER ON UPPER BEARING
5 - LOWER BEARING HALF
Fig. 37 Locking Tab Inspection
1 - ABNORMAL CONTACT AREA CAUSED BY LOCKING TABS
NOT FULLY SEATED OR BEING BENT
Fig. 38 Scoring Caused by Insufficient Lubrication
or Damaged Crankshaft Journal
TJ
ENGINE 4.0L
9 - 101
CAMSHAFT & BEARINGS (IN BLOCK) (Continued)
(7) Remove the bearing cap and determine amount
of bearing-to- journal clearance by measuring the
width of compressed Plastigage (Fig. 40). Plastigage
should indicate the same clearance across the
entire width of the insert. If the clearance var-
ies, it may be caused by either a tapered jour-
nal, bent connecting rod or foreign material
trapped between the insert and cap or rod.
(8) If the correct clearance is indicated, replace-
ment of the bearing inserts is not necessary. Remove
the Plastigage from crankshaft journal and bearing
insert. Proceed with installation.
(9) If
bearing-to-journal
clearance
exceeds
the
specification, install a pair of 0.0254 mm (0.001 inch)
undersize bearing inserts. All the odd size inserts
must be on the bottom. The sizes of the service
replacement bearing inserts are stamped on the
backs of the inserts. Measure the clearance as
described in the previous steps.
(10) The clearance is measured with a pair of
0.0254 mm (0.001 inch) undersize bearing inserts
installed. This will determine if two 0.0254 mm
(0.001 inch) undersize inserts or another combination
is needed to provide the correct clearance. Refer to
CONNECTING ROD BEARING FITTING CHART.
CONNECTING ROD BEARING FITTING CHART
CRANKSHAFT JOURNAL
CORRESPONDING ROD BEARING INSERT
Color Code
Diameter
Upper Insert Size
Lower Insert Size
Yellow
53.2257 - 53.2079 mm
Yellow - Standard
Yellow - Standard
(2.0955 - 2.0948 in.)
Orange
53.2079 - 53.1901 mm
Yellow - Standard
Blue - Undersize
(2.0948 - 2.0941 in.)
0.0178 mm (0.0007 in.)
0.025 mm (0.001 in.)
Undersize
Blue
53.1901 - 53.1724 mm
Blue - Undersize
Blue - Undersize
(2.0941 - 2.0934 in.)
0.0356 mm (0.0014 in.)
0.025 mm (0.001 in.)
0.025 mm (0.001 in.)
Undersize
Red
52.9717 - 52.9539 mm
Red - Undersize
Red - Undersize
(2.0855 - 2.0848 in.)
0.254 mm (0.010 in.)
0.254 mm (0.010 in.)
0.254 mm (0.010 in.)
Undersize
Fig. 39 Rod and Piston Assembly Installation
Fig. 40 Measuring Bearing Clearance with
Plastigage
1 - PLASTIGAGE SCALE
2 - COMPRESSED PLASTIGAGE
9 - 102
ENGINE 4.0L
TJ
CONNECTING ROD BEARINGS (Continued)
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