2002 JEEP LIBERTY CRANK SHAFT

INSTALLATION
CAUTION: If burr or scratch is present on the
crankshaft edge (chamfer), cleanup with 400 grit
sand paper to prevent seal damage during installa-
tion of new seal.
NOTE: When installing seal, no lube on seal is
needed.
(1) Place Special Tool 6926-1 Seal Guide on crank-
shaft (Fig. 57).
(2) Position seal over guide tool (Fig. 57). Guide
tool should remain on crankshaft during installation
of seal. Ensure that the lip of the seal is facing
towards the crankcase during installation.
CAUTION: If the seal is driven into the block past
flush, this may cause an oil leak.
(3) Drive the seal into the block using Special Tool
6926-2 and handle C-4171 (Fig. 58) until the tool bot-
toms out against the block (Fig. 59).
Fig. 56 Rear Crankshaft Oil SealÐRemoval
1 - REAR CRANKSHAFT SEAL
2 - ENGINE BLOCK
3 - ENGINE BLOCK
4 - REAR CRANKSHAFT SEAL METAL CASE
5 - PRY IN THIS DIRECTION
6 - CRANKSHAFT
7 - SCREWDRIVER
8 - REAR CRANKSHAFT SEAL DUST LIP
9 - SCREWDRIVER
Fig. 57 Rear Crankshaft Seal and Special Tool
6926-1
1 - SPECIAL TOOL 6926±1 PILOT
2 - SEAL
Fig. 58 Crankshaft Seal and Special Tools 6926-2 &
C-4171
1 - SPECIAL TOOL 6926±1 PILOT
2 - SEAL
3 - SPECIAL TOOL 6926±2 INSTALLER
4 - SPECIAL TOOL C-4171
KJENGINE9s-39
CRANKSHAFT OIL SEAL - REAR (Continued)

(4) Install flex plate. Apply MopartLock & Seal
Adhesive to bolt threads and tighten bolts to 95 N´m
(70 ft. lbs.).
(5) Install the transmission.
PISTON & CONNECTING ROD
DESCRIPTION
The pistons are made of a cast aluminum alloy.
The pistons have pressed-in pins attached to forged
powdered metal connecting rods. The pistons pin is
offset 1 mm (0.0394 in.) towards the thrust side of
the piston. The connecting rods are a cracked cap
design and are not repairable. Hex head cap screws
are used to provide alignment and durability in the
assembly. The pistons and connecting rods are ser-
viced as an assembly.
OPERATION
The piston and connecting rod is the link between
the combustion force to the crankshaft.
REMOVAL
NOTE: Cylinder Head must be removed before Pis-
tons and Rods. Refer to Cylinder Head Removal in
this section.
(1) Remove top ridge of cylinder bores with a reli-
able ridge reamer before removing pistons from cyl-
inder block.Be sure to keep tops of pistons
covered during this operation. Mark piston with
matching cylinder number (Fig. 60).
(2) Remove oil pan. Scribe the cylinder number on
the side of the rod and cap (Fig. 61) for identification.
(3) Pistons have a directional stamping in the
front half of the piston facing towards thefrontof
engine.
(4) Pistons and connecting rods must be removed
from top of cylinder block. Rotate crankshaft so that
each connecting rod is centered in cylinder bore.
(5) Remove Balance Shaft Assembly. Refer to Bal-
ance Shaft Removal in this section.
(6) Remove connecting rod cap bolts. Push each
piston and rod assembly out of cylinder bore.
NOTE: Be careful not to nick crankshaft journals.
(7) After removal, install bearing cap on the mat-
ing rod.
(8) Piston and Rods are serviced as an assembly.
Fig. 59 Rear Crankshaft SealÐInstallation
1 - SPECIAL TOOL 6926±2 INSTALLER
Fig. 60 Piston Markings
1 - DIRECTIONAL ARROW WILL BE IMPRINTED IN THIS AREA
9s - 40 ENGINEKJ
CRANKSHAFT OIL SEAL - REAR (Continued)

INSTALLATION
(1) Before installing pistons and connecting rod
assemblies into the bore, be sure that compression
ring gaps are staggered so that neither is in line with
oil ring rail gap.
(2) Before installing the ring compressor, make
sure the oil ring expander ends are butted and the
rail gaps located as shown in (Fig. 62). As viewed
from top.
(3) Immerse the piston head and rings in clean
engine oil, slide the ring compressor, over the piston
(Fig. 63).Be sure position of rings does not
change during this operation.
(4) The directional stamp on the piston should face
toward the front of the engine.
(5) Rotate crankshaft so that the connecting rod
journal is on the center of the cylinder bore. Insert
rod and piston assembly into cylinder bore and guide
rod over the crankshaft journal.(6) Tap the piston down in cylinder bore, using a
hammer handle. At the same time, guide connecting
rod into position on connecting rod journal.
NOTE: The connecting rod cap bolts should not be
reused.
(7) Before installing theNEWbolts the threads
should be coated with clean engine oil.
(8) Install each bolt finger tight than alternately
torque each bolt to assemble the cap properly.
CAUTION: Do not use a torque wrench for second
part of last step.
(9) Tighten the bolts to 54 N´m PLUS 1/4 turn (40
ft. lbs. PLUS 1/4 turn).
(10) Using a feeler gauge, check connecting rod
side clearance (Fig. 64).
Fig. 61 Identify Connecting Rod to Cylinder
Fig. 62 Piston Ring End Gap Position
1 - GAP OF LOWER SIDE RAIL
2 - NO. 1 RING GAP
3 - GAP OF UPPER SIDE RAIL
4 - NO. 2 RING GAP AND SPACER EXPANDER GAP
Fig. 63 PistonÐInstallation
Fig. 64 Checking Connecting Rod Side Clearance
KJENGINE9s-41
PISTON & CONNECTING ROD (Continued)

VIBRATION DAMPER
REMOVAL
(1) Remove accesory drive belts. (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL)
(2) Remove crankshaft damper bolt.
(3) Remove damper using Special Tool 3-Jaw
Puller 1026 and Insert 6827±A (Fig. 70).
INSTALLATION
(1) Install crankshaft vibration damper using M12
1.75 x 150 mm bolt, washer, thrust bearing and nut
from Special Tool 6792 (Fig. 71).
(2) Install crankshaft vibration damper bolt and
tighten to 142 N´m (105 ft. lbs.).
(3) Install accessory drive belts. (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION)
Fig. 68 Installing Side Rail - Typical
1 - SIDE RAIL END
Fig. 69 Piston
1 - GAP OF LOWER SIDE RAIL
2 - NO. 1 RING GAP
3 - GAP OF UPPER SIDE RAIL
4 - NO. 2 RING GAP AND SPACER EXPANDER GAP
Fig. 70 Crankshaft Vibration Damper - Removal -
Typical
1 - SPECIAL TOOL 1026 3-JAW PULLER
2 - SPECIAL TOOL 6827±A INSERT
Fig. 71 Crankshaft Vibration Damper - Installation -
Typical
1 - M12±1.75 ý 150 MM BOLT, WASHER AND THRUST BEARING
FROM SPECIAL TOOL 6792
KJENGINE9s-43
PISTON RINGS (Continued)

LUBRICATION
DESCRIPTION
The lubrication system is a full-flow filtration,
pressure feed type. The oil pump is mounted in the
front engine cover and driven by the crankshaft.
OPERATION
Engine oil drawn up through the pickup tube and
is pressurized by the oil pump and routed through
the full-flow filter to the main oil gallery running the
length of the cylinder block. A diagonal hole in each
bulkhead feeds oil to each main bearing. Drilled pas-
sages within the crankshaft route oil from main bear-
ing journals to connecting rod journals. Balance shaft
lubrication is provided through an oil passage from
the number one main bearing cap through the bal-
ance shaft carrier support leg. This passage directly
supplies oil to the front bearings and internal
machined passages in the shafts that routes oil from
front to the rear shaft bearing journals. A vertical
hole at the number five bulkhead routes pressurized
oil through a restrictor (integral to the cylinder head
gasket) up past a cylinder head bolt to an oil gallery
running the length of the cylinder head. The cam-
shaft journals are partially slotted to allow a prede-
termined amount of pressurized oil to pass into the
bearing cap cavities. Lubrication of the camshaft
lobes are provided by small holes in the camshaft
bearing caps that are directed towards each lobe. Oil
returning to the pan from pressurized components
supplies lubrication to the valve stems. Cylinder
bores and wrist pins are splash lubricated from
directed slots on the connecting rod thrust collars.
DIAGNOSIS AND TESTING - ENGINE OIL
PRESSURE CHECKING
(1) Disconnect and remove oil pressure switch.
(Refer to 9 - ENGINE/LUBRICATION/OIL PRES-
SURE SENSOR/SWITCH - REMOVAL)
(2) Install Special Tools C-3292 Gauge with 8406
Adaptor fitting.
(3) Start engine and record oil pressure. Refer to
Specifications for correct oil pressure requirements.
(Refer to 9 - ENGINE - SPECIFICATIONS)
CAUTION: If oil pressure is 0 at idle, do not perform
the 3000 RPM test
(4) If oil pressure is 0 at idle. Shut off engine,
check for pressure relief valve stuck open, a clogged
oil pick-up screen or a damaged oil pick-up tube
O-ring.
(5) After test is complete, remove test gauge and
fitting.
Fig. 76 TRANSMISSION MOUNT 3.7L 2WD AUTO
TRANS
1 - BOLT
2 - MOUNT
Fig. 77 TRANSMISSION MOUNT 3.7L 4WD AUTO
TRANS
1 - MOUNT
2 - BOLT
9s - 46 ENGINEKJ
LUBRICATION (Continued)

instrument panel on either a CCD or PCI bus circuit
(depending on vehicle line) to operate the oil pressure
gauge and the check gauges lamp. Ground for the
sensor is provided by the PCM through a low-noise
sensor return.
OIL PUMP
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove timing belt. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - REMOVAL)
(3) Remove timing belt rear cover. (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - REMOVAL)
(4) Remove oil pan. (Refer to 9 - ENGINE/LUBRI-
CATION/OIL PAN - REMOVAL)
(5) Remove crankshaft sprocket using Special
Tools 6793 and C-4685-C2 (Fig. 81).
(6) Remove crankshaft key (Fig. 82).
(7) Remove oil pick-up tube.
(8) Remove oil pump (Fig. 83) and front crankshaft
seal.
DISASSEMBLY
(1) To remove the relief valve, proceed as follows:
(a) Remove the threaded plug and gasket from
the oil pump.
(b) Remove spring and relief valve.
(2) Remove oil pump cover fasteners, and lift off
cover.
(3) Remove pump rotors.
(4) Wash all parts in a suitable solvent and
inspect carefully for damage or wear.
CLEANING
(1) Clean all parts thoroughly in a suitable sol-
vent.
Fig. 81 Crankshaft Sprocket - Removal
1 - SPECIAL TOOL 6793
2 - SPECIAL TOOL C-4685±C2
3 - CRANKSHAFT SPROCKET
Fig. 82 Crankshaft Key
1 - CRANKSHAFT KEY
Fig. 83 2.4L OIL PUMP
1 - BOLTS
2 - BOLTS
KJENGINE9s-49
OIL PRESSURE SENSOR/SWITCH (Continued)

INSPECTION
(1) Inspect the mating surface of the oil pump.
Surface should be smooth. Replace pump cover if
scratched or grooved.
(2) Lay a straightedge across the pump cover sur-
face (Fig. 84). If a 0.025 mm (0.001 in.) feeler gauge
can be inserted between cover and straight edge,
cover should be replaced.
(3) Measure thickness and diameter of outer rotor.
If outer rotor thickness measures 9.40 mm (0.370 in.)
or less (Fig. 85), or if the diameter is 79.95 mm
(3.148 in.) or less, replace outer rotor.
(4) If inner rotor measures 9.40 mm (0.370 in.) or
less replace inner rotor (Fig. 86).
ASSEMBLY
(1) Assemble pump, using new parts as required.
Install the inner rotor with chamfer facing the
cast iron oil pump cover.
(2) Prime oil pump before installation by filling
rotor cavity with engine oil.
(3) Install cover and tighten fasteners to 12 N´m
(105 in. lbs.).
CAUTION: Oil pump pressure relief valve must be
installed correctly or serious engine damage may
occur.
(4) Install relief valve, spring, gasket and cap.
Tighten cap to 41 N´m (30 ft. lbs.).
INSTALLATION
(1) Make sure all surfaces are clean and free of oil
and dirt.
(2) Apply MopartGasket Maker to oil pump as
shown in (Fig. 87). Install O-ring into oil pump body
discharge passage.
(3) Prime oil pump with engine oil before installa-
tion.
(4) Align oil pump rotor flats with flats on crank-
shaft. Install the oil pump to the block.
CAUTION: To align, the front crankshaft seal MUST
be out of pump, or damage may result.
(5) Install new front crankshaft seal using Special
Tool 6780 (Fig. 88).
(6) Install crankshaft key (Fig. 82).
CAUTION: The crankshaft sprocket is set to a pre-
determined depth from the factory for correct tim-
ing belt tracking. If removed, use of Special Tool
6792 is required to set the sprocket to original
installation depth. An incorrectly installed sprocket
will result in timing belt and engine damage.
Fig. 84 Checking Oil Pump Cover Flatness
1 - STRAIGHT EDGE
2 - FEELER GAUGE
3 - OIL PUMP COVER
Fig. 85 Measuring Outer Rotor Thickness
Fig. 86 Measuring Inner Rotor Thickness
9s - 50 ENGINEKJ
OIL PUMP (Continued)

(7) Install crankshaft sprocket using Special Tool
6792 (Fig. 89).
(8) Install oil pump pick-up tube.(9) Install oil pan. (Refer to 9 - ENGINE/LUBRI-
CATION/OIL PAN - INSTALLATION)
(10) Install timing belt rear cover. (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION)
(11) Install timing belt. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - INSTALLATION)
INTAKE MANIFOLD
DESCRIPTION
The intake manifold is a one piece composite mod-
ule that attaches to the cylinder head with fasteners.
The manifold is a long branch design to enhance low
and mid-range torque
OPERATION
The intake manifold delivers air to the combustion
chambers. This air allows the fuel delivered by the
fuel injectors to ignite when the spark plug fire.
DIAGNOSIS AND TESTING - INTAKE
MANIFOLD LEAKS
An intake manifold air leak is characterized by
lower than normal manifold vacuum. Also, one or
more cylinders may not be functioning.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS OR THE FAN.
DO NOT WEAR LOOSE CLOTHING.
(1) Start the engine.
Fig. 87 Oil Pump Sealing - Typical
1 - O-RING
2 - SEALER LOCATION
Fig. 88 Front Crankshaft Seal - Installation
1 - PROTECTOR
2 - SEAL
3 - SPECIAL TOOL 6780
Fig. 89 Crankshaft Sprocket - Installation
1 - SPECIAL TOOL 6792
2 - TIGHTEN NUT TO INSTALL
KJENGINE9s-51
OIL PUMP (Continued)