2002 JEEP LIBERTY engine block

OPERATION
The crankshaft transfers force generated by com-
bustion within the cylinder to the flywheel or flex-
plate.
STANDARD PROCEDURE - CRANKSHAFT END
PLAY
(1) Using Dial Indicator C-3339 and Mounting
Post L-4438, attach to front of engine, locating probe
perpendicular on nose of crankshaft (Fig. 40).
(2) Move crankshaft all the way to the rear of its
travel.
(3) Zero the dial indicator.
(4) Move crankshaft all the way to the front and
read the dial indicator. Refer to Engine Specifica-
tions.
REMOVAL
NOTE: Crankshaft can not be removed when engine
is in vehicle.
(1) Remove engine assembly from vehicle. (Refer to
9 - ENGINE - REMOVAL)
(2) Remove flex plate and crankshaft rear oil seal.
(3) Mount engine on a repair stand.
(4) Drain engine oil and remove oil filter.
(5) Remove the oil pan. (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - REMOVAL)
(6) Remove the timing belt covers. (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - REMOVAL)(7) Remove the timing belt. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - REMOVAL)
(8) Remove the oil pump. (Refer to 9 - ENGINE/
LUBRICATION/OIL PUMP - REMOVAL)
(9) Remove balance shafts and housing assembly.
(Refer to 9 - ENGINE/VALVE TIMING/BALANCE
SHAFT - REMOVAL)
(10) Remove all bedplate bolts from the engine
block (Fig. 41).
(11) Using a mallet gently tap the bedplate loose
from the engine block dowel pins.
CAUTION: Do not pry up on one side of the bed-
plate. Damage may occur to cylinder block to bed-
plate alignment and thrust bearing.
(12) Bedplate should be removed evenly from the
cylinder block dowel pins to prevent damage to the
dowel pins and thrust bearing.
(13) Lift out crankshaft from cylinder block. Do
not damage the main bearings or journals when
removing the crankshaft.
Fig. 39 Crankshaft - Typical
1 - MAIN BEARING JOURNALS
2 - COUNTER BALANCE WEIGHTS
Fig. 40 CHECKING CRANKSHAFT END PLAY
Fig. 41 Bedplate Bolt Tightenening Sequence
KJENGINE9s-33
CRANKSHAFT (Continued)

INSPECTION
The crankshaft journals should be checked for
excessive wear, taper and scoring (Fig. 42). Limits of
taper or out of round on any crankshaft journals
should within specitifications. (Refer to 9 - ENGINE -
SPECIFICATIONS) Journal grinding should not
exceed 0.305 mm (0.012 in.) under the standard jour-
nal diameter. DO NOT grind thrust faces of No. 3
main bearing. DO NOT nick crank pin or bearing fil-
lets. After grinding, remove rough edges from crank-
shaft oil holes and clean out all passages.
CAUTION: With the nodular cast iron crankshafts, it
is important that the final paper or cloth polish be
in the same direction as normal rotation in the
engine.
INSTALLATION
(1) Install the main bearing shells with the lubri-
cation groove in the cylinder block (Fig. 43).
(2) Make certain oil holes in block line up with oil
hole in bearings and bearing tabs seat in the block
tab slots.
CAUTION: Do not get oil on the bedplate mating
surface. It will affect the sealer ability to seal the
bedplate to cylinder block.
(3) Oil the bearings and journals. Install crank-
shaft.
CAUTION: Use only the specified anaerobic sealer
on the bedplate or damage may occur to the
engine.
(4) Apply 1.5 to 2.0 mm (0.059 to 0.078 in.) bead of
MopartBed Plate Sealant to cylinder block as shown
in (Fig. 44).
(5) Install lower main bearings into main bearing
cap/bedplate. Make certain the bearing tabs areseated into the bedplate slots. Install the main bear-
ing/bedplate into engine block.
Fig. 42 Crankshaft Journal Measurements
Fig. 43 Installing Main Bearing Upper Shell
1 - LUBRICATION GROOVES
2 - OIL HOLES
Fig. 44 Bedplate Sealing
Fig. 45 Bedplate Bolt Torque Sequence
9s - 34 ENGINEKJ
CRANKSHAFT (Continued)

(6) Before installing the bolts the threads should
be oiled with clean engine oil, wipe off any excess oil.
(7) Install main bearing bedplate to engine block
bolts 11, 17, and 20 finger tight. Tighten these bolts
down together until the bedplate contacts the cylin-
der block.
(8) To ensure correct thrust bearing alignment,
perform the following steps:
²Step 1: Rotate crankshaft until number 4 piston
is at TDC.
²Step 2: Move crankshaft rearward to limits of
travel.
²Step 3: Then, move crankshaft forward to limits
of travel.
²Step 4: Wedge an appropriate tool between the
rear of the cylinder block(NOT BED PLATE)and
the rear crankshaft counterweight. This will hold the
crankshaft in it's furthest forward position.
²Step 5: Install and tighten bolts (1±10) in
sequence shown in (Fig. 45) to 41 N´m (30 ft. lbs.).
²Step 6: Remove wedge tool used to hold crank-
shaft.
(9) Tighten bolts (1±10) again to 41 N´m (30 ft.
lbs.) +1/4 turn in sequence shown in (Fig. 45).
(10) Install main bearing bedplate to engine block
bolts (11±20), and torque each bolt to 28 N´m (20 ft.
lbs.) in sequence shown in (Fig. 45).
(11) After the main bearing bedplate is installed,
check the crankshaft turning torque. The turning
torque should not exceed 5.6 N´m (50 in. lbs.).
(12) Install balance shafts and housing assembly.
(Refer to 9 - ENGINE/VALVE TIMING/BALANCE
SHAFT - INSTALLATION)
(13) Install the oil pump and pickup tube. (Refer
to 9 - ENGINE/LUBRICATION/OIL PUMP -
INSTALLATION)
(14) Install the timing belt rear cover. (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION)
(15) Install the timing belt. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - INSTALLATION)
(16) Install the timing belt front covers. (Refer to 9
- ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION)
(17) Install engine support bracket.
(18) Install the oil pan. (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - INSTALLATION)
(19) Install the oil filter.
(20) Install crankshaft rear oil seal. (Refer to 9 -
ENGINE/ENGINE BLOCK/CRANKSHAFT OIL
SEAL - REAR - INSTALLATION)
(21) Install flex plate. Apply MopartLock & Seal
Adhesive to bolt threads and tighten to 95 N´m (70
ft. lbs.).(22) Install the engine assembly. (Refer to 9 -
ENGINE - INSTALLATION)
CRANKSHAFT MAIN
BEARINGS
STANDARD PROCEDURE - MAIN BEARING -
FITTING
For crankshaft specifications (Refer to 9 - ENGINE
- SPECIFICATIONS).
CRANKSHAFT MAIN BEARINGS
The crankshaft is supported in five main bearings.
All upper and lower bearing shells in the crankcase
have oil grooves. Crankshaft end play is controlled by
a flanged bearing on the number three main bearing
journal (Fig. 46).
Upper and lower Number 3 bearing halves are
flanged to carry the crankshaft thrust loads and are
NOT interchangeable with any other bearing halves
in the engine (Fig. 46). All bearing cap bolts removed
during service procedures are to be cleaned and oiled
before installation. Bearing shells are available in
standard and the following undersized: 0.025 mm
(0.001 in.) and 0.250 mm (0.010 in.). Never install an
undersize bearing that will reduce clearance below
specifications. Replace or machine the crankshaft as
necessary to obtain proper bearing clearances.
MAIN BEARING INSTALLATION
(1) Install the main bearing shells with the lubri-
cation groove in the cylinder block (Fig. 47).
Fig. 46 Main Bearing Identification
1 - OIL GROOVE
2 - MAIN BEARINGS
3 - OIL HOLE
KJENGINE9s-35
CRANKSHAFT (Continued)

(2) Make certain oil holes in block line up with oil
holes in bearings. Bearing tabs must seat in the
block tab slots.
CAUTION: Do not get oil on the bedplate mating
surface. It will may effect the sealer ability to seal
the bedplate to cylinder block.
(3) Oil the bearings and journals and install
crankshaft.
CAUTION: Use only the specified anaerobic sealer
on the bedplate or damage may occur to the
engine. Ensure that both cylinder block and bed-
plate surfaces are clean.
(4) Apply 1.5 to 2.0 mm (0.059 to 0.078 in.) bead
of anaerobic sealer MopartBed Plate Sealant to cyl-
inder block as shown in (Fig. 48).(5) Install lower main bearings into main bearing
cap/bedplate. Make certain the bearing tabs are
seated into the bedplate slots.
(6) Position the main bearing/bedplate onto the
engine block.
(7) Before installing bolts, lubricate the threads
with clean engine oil, wipe off any excess oil.
(8) Install main bearing bedplate to engine block
bolts 11, 17 and 20 finger tight. Tighten these bolts
down together until the bedplate contacts the cylin-
der block.
(9) To ensure correct thrust bearing alignment,
perform the following steps:
²Step 1: Rotate crankshaft until number 4 piston
is at TDC.
²Step 2: Move crankshaft rearward to limits of
travel.
²Step 3: Then, move crankshaft forward to limits
of travel.
²Step 4: Wedge an appropriate tool between the
rear of the cylinder block(NOT BED PLATE)and
the rear crankshaft counterweight. This will hold the
crankshaft in it's furthest forward position.
²Step 5: Install and tighten bolts (1±10) in
sequence shown in (Fig. 49) to 41 N´m (30 ft. lbs.).
²Step 6: Remove wedge tool used to hold crank-
shaft.
(10) Tighten bolts (1±10) again to 41 N´m (30 ft.
lbs.)PLUS1/4 turn in sequence shown in (Fig. 49).
(11) Install main bearing bedplate to engine block
bolts (11±20), and torque each bolt to 28 N´m (20 ft.
lbs.) in sequence shown in (Fig. 49).
(12) After the main bearing bedplate is installed,
check the crankshaft turning torque. The turning
torque should not exceed 5.6 N´m (50 in. lbs.).
Fig. 47 Installing Main Bearing Upper Shell
1 - LUBRICATION GROOVES
2 - OIL HOLES
Fig. 48 Main Bearing Caps/Bedplate Sealing
Fig. 49 Main Bearing Caps/Bedplate Tightening
Sequence
9s - 36 ENGINEKJ
CRANKSHAFT MAIN BEARINGS (Continued)

CRANKSHAFT OIL SEAL -
FRONT
REMOVAL
(1) Remove the crankshaft vibration damper (Fig.
50). (Refer to 9 - ENGINE/ENGINE BLOCK/VIBRA-
TION DAMPER - REMOVAL)
(2) Remove timing belt. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - REMOVAL)
(3) Remove crankshaft sprocket using Special Tool
6793 and insert C-4685-C2 (Fig. 51).
CAUTION: Do not nick shaft seal surface or seal
bore.
(4) Using Tool 6771 to remove front crankshaft oil
seal (Fig. 52). Be careful not to damage the seal sur-
face of cover.
INSTALLATION
(1) Install new seal by using Special Tool 6780
(Fig. 53).
(2) Place seal into opening with seal spring
towards the inside of engine. Install seal until flush
with cover.
Fig. 50 Crankshaft Vibration Damper - Removal -
Typical
1 - SPECIAL TOOL 1026 3-JAW PULLER
2 - SPECIAL TOOL 6827±A INSERT
Fig. 51 Crankshaft Sprocket - Removal
1 - SPECIAL TOOL 6793
2 - CRANKSHAFT SPROCKET
Fig. 52 Front Crankshaft Oil Seal - Removal
1 - SPECIAL TOOL 6771
2 - REAR TIMING BELT COVER
KJENGINE9s-37

(3) Install crankshaft sprocket using Special Tool
6792 (Fig. 54).(4) Install timing belt. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - INSTALLATION)
(5) Install crankshaft vibration damper (Fig. 55).
(Refer to 9 - ENGINE/ENGINE BLOCK/VIBRATION
DAMPER - INSTALLATION)
CRANKSHAFT OIL SEAL -
REAR
REMOVAL
(1) Remove transmission.
(2) Remove flex plate.
(3) Insert a 3/16 flat bladed screwdriver between
the dust lip and the metal case of the crankshaft
seal. Angle the screwdriver (Fig. 56)through the dust
lip against metal case of the seal. Pry out seal.
CAUTION: Do not permit the screwdriver blade to
contact crankshaft seal surface. Contact of the
screwdriver blade against crankshaft edge (cham-
fer) is permitted.
Fig. 53 Crankshaft Front Oil Seal - Installation
1 - PROTECTOR
2 - SEAL
3 - SPECIAL TOOL 6780
Fig. 54 Crankshaft Sprocket - Installation
1 - SPECIAL TOOL 6792
2 - TIGHTEN NUT TO INSTALL
Fig. 55 Crankshaft Vibration Damper - Installation -
Typical
1 - M12±1.75 ý 150 MM BOLT, WASHER AND THRUST BEARING
FROM SPECIAL TOOL 6792
9s - 38 ENGINEKJ
CRANKSHAFT OIL SEAL - FRONT (Continued)

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)