BALANCE SHAFT JEEP LIBERTY 2002 KJ / 1.G Owner's Manual

DESCRIPTION SPECIFICATION
Valve Springs
Free Length (Approx.) 48.4 mm
(1.905 in.)
Nominal Force (Valve
Closed)338 N @ 38.0 mm
(75.98 lbs. @ 1.496 in.)
Nominal Force (Valve
Open)607 N @ 29.75 mm
(136 lbs. @ 1.172 in.)
Installed Height 38.00 mm
(1.496 in.)
Number of Coils 7.82
Wire Diameter 3.86 mm
(1.496 in.)
Oil Pump
Clearance Over Rotors
(Max.)0.10 mm
(0.004 in.)
Cover Out-of-Flat (Max.) 0.025 mm
(0.001 in.)
Inner Rotor Thickness
(Min.)9.40 mm
(0.370 in.)
Outer Rotor Thickness
(Min.)9.40 mm
(0.370 in.)
Outer Rotor Clearance
(Max.)0.039 mm
(0.015 in.)
Outer Rotor Diameter
(Min.)79.95 mm
(3.148 in.)
Tip Clearance Between
Rotors (Max.)0.20 mm
(0.008 in.)
Oil Pressure
At Curb Idle Speed* 25 kPa
(4 psi)
At 3000 rpm 170±550 kPa
(25±80 psi)
CAUTION:
*If pressure is ZERO at curb idle, DO NOT run engine
at 3000 rpm.SPECIFICATIONS - TORQUE
DESCRIPTION N´mFt.
Lbs.In.
Lbs.
Balance Shaft Carrier to
BlockÐBolts54 40 Ð
Balance Shaft Gear
CoverÐDouble Ended
Fastener12 Ð 105
Balance Shaft SprocketÐ
Bolt28 Ð 250
Balance Shaft Chain
TensionerÐBolts12 Ð 105
Balance Shaft Carrier
CoverÐBolts12 Ð 105
Camshaft SprocketÐBolt 101 75 Ð
Connecting Rod
CapÐBolts54 +
1¤4
turn40
+1¤4
turnÐ
Crankshaft Main Bearing
Cap/Bedplate
ÐM8 Bolts 34 250
ÐM11 Bolts 41 +
1¤4
Turn30
+1¤4
TurnÐ
Crankshaft Damper 136 100 Ð
Cylinder HeadÐBolts (Refer to 9 - ENGINE/
CYLINDER HEAD -
INSTALLATION)
Cylinder Head CoverÐ
Bolts12 Ð 105
Flex Plate to Crankshaft 95 70 Ð
Flywheel Mounting Bolts 81 60 Ð
Engine Mount Bracket
RightÐBolts61 45 Ð
Engine MountingÐBolts (Refer to 9 ENGINE/
ENGINE MOUNTING)
Exhaust Manifold to
Cylinder HeadÐBolts23 Ð 200
Exhaust Manifold Heat
ShieldÐBolts12 Ð 105
Intake Manifold - Lower
ÐBolts28 Ð 250
Oil Filter 20 15 Ð
Oil PanÐBolts 12 Ð 105
Oil Pan DrainÐPlug 27 20 Ð
Oil Pump to BlockÐBolts 28 Ð 250
9s - 16 ENGINEKJ
ENGINE - 2.4L (Continued)

Valve Spring Compressor MD-998772-A
Valve Spring Compressor Adapter 6779
Cylinder Bore Gage C-119
Crankshaft Sprocket Remover 6793
Crankshaft Sprocket Remover Insert C-4685-C2
Crankshaft Seal Remover 6771
Oil Pressure Gage C-3292
Rear Crankshaft Seal Guide and Installer 6926-1 and
6926-2
Balance Shaft Sprocket Installer 6052
Front Crankshaft Oil Seal Installer 6780
9s - 18 ENGINEKJ
ENGINE - 2.4L (Continued)

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)

(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)

(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)

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)

TIMING BELT TENSIONER &
PULLEY
REMOVAL
(1) Remove the timing belt. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - REMOVAL)
(2) Remove timing belt idler pulley.
(3) Hold camshaft sprocket with Special Tool 6847
while removing bolt (Fig. 104). Remove both cam
sprockets.
(4) Remove rear timing belt cover fasteners and
remove cover from engine (Fig. 105).
(5) Remove lower bolt attaching timing belt ten-
sioner assembly to engine and remove tensioneras
an assembly.
INSTALLATION
(1) Align timing belt tensioner assembly to engine
and install lower mounting boltbut do not tighten.
To properly align tensioner assemblyÐinstall one of
the engine bracket mounting bolts (M10) 5 to 7 turns
into the tensioner's upper mounting location.
(2) Torque the tensioner's lower mounting bolt to
61 N´m (45 ft. lbs.). Remove the upper bolt used for
tensioner alignment.
(3) Install rear timing belt cover and fasteners.
(4) Install timing belt idler pulley and torque
mounting bolt to 61 N´m (45 ft. lbs.).(5) Install camshaft sprockets. Use Special Tool
6847 to hold sprockets, torque bolts to 101 N´m (75
ft. lbs.).
(6) Install the timing belt. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - INSTALLATION)
BALANCE SHAFT
DESCRIPTION
The 2.4L engine is equipped with two nodular cast
iron balance shafts installed in a cast aluminum car-
rier attached to the lower cylinder block (Fig. 106).
OPERATION
The balance shafts are driven by the crankshaft
via a roller chain and sprockets. The balance shafts
are connected by helical gears. The dual counter
rotating shafts decrease second order vertical shak-
ing forces caused by component movement.
Fig. 104 Camshaft Sprocket - Removal/Installation
1 - SPECIAL TOOL 6847
Fig. 105 TIMING BELT REAR COVER FASTENERS
1 - OUTER COVER TO REAR COVER FASTENERS (3)
2 - REAR COVER TO CYLINDER HEAD FASTENERS
3 - OUTER COVER TO REAR COVER FASTENERS (3)
4 - INNER COVER TO BLOCK FASTENERS
KJENGINE9s-59

REMOVAL
BALANCE SHAFTS
(1) Drain engine oil.
(2) Remove the oil pan. (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - REMOVAL)
(3) Remove chain cover, guide and tensioner (Fig.
107). Also see Carrier Assembly Removal for service
procedures requiring only temporary relocation of
assembly.
(4) Remove gear cover retaining stud (double
ended to also retain chain guide). Remove cover and
balance shaft gears (Fig. 107).
(5) Remove balance shaft gear, chain sprocket
retaining screws, and crankshaft chain sprocket.
Remove chain and sprocket assembly (Fig. 108).
Using two wide pry bars, work the sprocket back and
forth until it is off the shaft.(6) Remove carrier gear cover and balance shafts
(Fig. 109).
(7) Remove four carrier to crankcase attaching
bolts to separate carrier from engine bedplate.
BALANCE SHAFT CARRIER
The following components will remain intact dur-
ing carrier removal. Gear cover, gears, balance shafts
and the rear cover (Fig. 110).
(1) Remove chain cover and driven balance shaft
chain sprocket screw.
(2) Loosen tensioner pivot and adjusting screws,
move driven balance shaft inboard through driven
chain sprocket. Sprocket will hang in lower chain
loop.
(3) Remove carrier to crankcase attaching bolts to
remove carrier.
Fig. 106 Balance Shafts and Carrier Assembly
1 - SPROCKET 7 - GEARS
2 - TENSIONER 8 - GEAR COVER
3 - PLUG 9 - CHAIN COVER
4 - CARRIER 10 - SPROCKET
5 - REAR COVER 11 - GUIDE
6 - BALANCE SHAFTS 12 - CHAIN
9s - 60 ENGINEKJ
BALANCE SHAFT (Continued)

INSTALLATION
BALANCE SHAFT TIMING
BALANCE SHAFT INSTALLATION
Balance shaft and carrier assembly installation is
the reverse of the removal procedure.During instal-
lation crankshaft-to-balance shaft timing must
be established. Refer to Timing procedure in
this section.
(1) With balance shafts installed in carrier (Fig.
110) position carrier on crankcase and install four
attaching bolts and tighten to 54 N´m (40 ft. lbs.).
(2) Turn balance shafts until both shaft key ways
are up, parallel to vertical centerline of engine.
Install short hub drive gear on sprocket driven shaft
and long hub gear on gear driven shaft. After instal-
lation gear and balance shaft keyways must be up
with gear timing marks meshed as shown in (Fig.
111).
(3) Install gear cover and tighten double ended
stud/washer fastener to 12 N´m (105 in. lbs.).
(4) Align flat on balance shaft drive sprocket to the
flat on crankshaft (Fig. 112).
Fig. 107 Chain Cover, Guide and Tensioner
1 - STUD
2 - TENSIONER (ADJUSTER)
3 - GEAR COVER
4 - ADJUST SCREW
5 - PIVOT SCREW
6 - CHAIN COVER (CUTAWAY)
7 - GUIDE
Fig. 108 Drive Chain and Sprockets
1 - NICKEL PLATED LINK AND MARK
2 - GEAR/SPROCKET SCREWS
3 - NICKEL PLATED LINK AND DOT
Fig. 109 Gear Cover and Gears
1 - STUD (DOUBLE ENDED)
2 - DRIVE GEAR
3 - DRIVEN GEAR
4 - CARRIER DOWEL
5 - GEAR(S)
6 - GEAR COVER
KJENGINE9s-61
BALANCE SHAFT (Continued)

(5) Install balance shaft drive sprocket on crank-
shaft using Special Tool 6052 (Fig. 113).
(6) Turn crankshaft until number 1 cylinder is at
top dead center (TDC). The timing marks on the
chain sprocket should line up with the parting line
on the left side of number one main bearing cap.
(Fig. 114).
(7) Place chain over crankshaft sprocket so that
the plated link of the chain is over the number 1 cyl-
inder timing mark on the balance shaft crankshaft
sprocket (Fig. 114).(8) Place balance shaft sprocket into the timing
chain (Fig. 114) and align the timing mark on the
sprocket (dot) with the (lower) plated link on the
chain.
NOTE: The lower plated link is 8 links from the
upper link.
Fig. 110 Balance Shaft - Removal/Installation
1 - REAR COVER
2 - CARRIER
3 - BALANCE SHAFT
Fig. 111 Gear Timing
1 - KEY WAYS UP
2 - GEAR ALIGNMENT DOTS
Fig. 112 Balance Shaft Sprocket Alignment to
Crankshaft
1 - ALIGN FLATS
Fig. 113 Balance Shaft Drive
1 - SPROCKET
2 - SPECIAL TOOL 6052
9s - 62 ENGINEKJ
BALANCE SHAFT (Continued)