2002 JEEP LIBERTY tdc

IDLER SHAFT
REMOVAL
(1) Remove the primary and secondary timing
chains and sprockets. Refer to procedure in this sec-
tion.
NOTE: To remove the idler shaft, it is necessary to
tap threads into the shaft, to install the removal
tool.
(2) Using a 12 mm X 1.75 tap, cut threads in the
idler shaft center bore.
(3) Cover the radiator core with a suitable cover.
CAUTION: Use care when removing the idler shaft,
Do not strike the radiator cooling fins with the slide
hammer.
(4) Using Special Tool 8517 Slide Hammer, remove
the idler shaft.
INSTALLATION
(1) Thoroughly clean the idler shaft bore.
(2) Position the idler shaft in the bore.
NOTE: The two lubrication holes in the idler shaft
do not require any special alignment.
NOTE: Before using the retaining bolt to install the
idler shaft, coat the threads and the pilot on the
idler shaft, with clean engine oil.
(3) Using the primary idler sprocket retaining bolt
and washer, carefully draw the idler shaft into the
bore until fully seated.
(4) Coat the idler shaft with clean engine oil.
(5) Install the timing chains and sprockets. Refer
to procedure in this section.
TIMING BELT/CHAIN AND
SPROCKET(S
REMOVAL
(1) Disconnect negative cable from battery.
(2) Drain cooling system. Refer to COOLING SYS-
TEM for procedures.
(3) Remove right and left cylinder head covers.
Refer to CYLINDER HEAD COVER.
(4) Remove radiator fan shroud. Refer to COOL-
ING SYSTEM for procedure.
(5) Rotate engine until timing mark on crankshaft
damper aligns with TDC mark on timing chain cover
(Fig. 103) (#1 cylinder exhaust stroke) and the cam-
shaft sprocket ªV6º marks are at the 12 o'clock posi-
tion (Fig. 102).
CAUTION: The nut on the right side camshaft
sprocket should not be removed for any reason, as
the sprocket and camshaft sensor target wheel is
serviced as an assembly. If the nut was removed
retorque nut to 5 N´m (44 in. lbs.).
(6) Remove power steering pump. Refer to STEER-
ING for procedure.
(7) Remove access plug from left and right cylinder
heads for access to chain guide fasteners (Fig. 104).
(8) Remove the oil fill housing to gain access to the
right side tensioner arm fastener.
(9) Remove crankshaft damper and timing chain
cover. Refer to procedures.
(10) Collapse and pin primary chain tensioner.
CAUTION: Plate behind left secondary chain ten-
sioner could fall into oil pan. Therefore, cover pan
opening.
(11) Remove secondary chain tensioners.
(12) Remove camshaft position and crankshaft
position sensors (Fig. 105) and (Fig. 106).
KJENGINE - 3.7L 9 - 77

DESCRIPTION SPECIFICATION
Exhaust 6.60 mm
(0.259 t>
Intake Valve Timing*
Closes (ABDC) 51É
Opens (BTDC) 1É
Duration 232É
Exhaust Valve Timing*
Closes (ATDC) 7É
Opens (BBDC) 47É
Duration 234É
Valve Overlap 8É
*All readings in crankshaft degrees. Timing points @
4É from top of Ramps.
Cylinder Head
Material Cast Aluminum
Gasket Thickness
(Compressed)0.71 mm
(0.028 in.)
Valve Seat
Angle 44.5±45É
Seat DiameterÐIntake 34.37±34.63 mm
(1.353±1.363 in.)
Seat DiameterÐExhaust 27.06±27.32 mm
(1.065±1.075 in.)
Runout (Max.) 0.05 mm
(0.002 in.)
Valve Seat WidthÐIntake
and Exhaust0.9±1.3 mm
(0.035±0.051 in.)
Service LimitÐIntake 2.0 mm
(0.079 in.)
Service LimitÐExhaust 2.5 mm
(0.098 in.)
Valve Guide
Diameter I.D. 5.975±6.000 mm
(0.235±0.236 in.)
Guide Bore Diameter 11.0±11.02 mm
(0.4330±0.4338 in.)
Guide Height (spring seat
to guide tip)13.25±13.75 mm
(0.521±0.541 in.)
Valves
Face AngleÐIntake and
Exhaust44.5Ð45ÉDESCRIPTION SPECIFICATION
Head DiameterÐIntake 34.67±34.93 mm
1.364±1.375 in.)
Head DiameterÐExhaust 28.32±28.52 mm
(1.114±1.122 in.)
Valve Length (Overall)
ÐIntake 112.76±113.32 mm
(4.439±4.461 in.)
ÐExhaust 110.89±111.69 mm
(4.365±4.397 in.)
Valve Stem Diameter
ÐIntake 5.934±5.952 mm
(0.2337±0.2344 in.)
ÐExhaust 5.906±5.924 mm
(0.2326±0.2333 in.)
Valve Margin
Intake 1.2±1.7 mm
(0.047±0.066 in.)
Service Limit 0.95 mm
(1/32 in.)
Exhaust 0.985±1.315 mm
(0.038±0.051 in.)
Service Limit 1.05 mm
(3/64 in.)
Valve Stem Tip
Intake 48.04 mm
(1.891 in.)
Exhaust 47.99 mm
(1.889 in.)
Valve Stem to Guide Clearance
Intake 0.048±0.066 mm
(0.0018±0.0025 in.)
Max. Allowable 0.076 mm
(0.003 in.)
Service Limit 0.25 mm
(0.010 in.)
Exhaust 0.0736±0.094 mm
(0.0029±0.0037 in.)
Max. Allowable 0.101 mm
(0.004 in.)
Service Limit 0.25 mm
(0.010 in.)
KJENGINE9s-15
ENGINE - 2.4L (Continued)

(4) Install cylinder head cover assembly to cylin-
der head. Install all bolts, ensuring the two (2) bolts
containing the sealing washer are located in the cen-
ter locations of cover. Tighten bolts in sequence
shown in (Fig. 25). Using a 3 step torque method as
follows:
(a) Tighten all bolts to 4.5 N´m (40 in. lbs.).
(b) Tighten all bolts to 9.0 N´m (80 in. lbs.).
(c) Tighten all bolts to 12 N´m (105 in. lbs.).
(5) Install intake manifold.
(6) Install ignition coil and spark plug wires.
Tighten fasteners to 12 N´m (105 in. lbs.).
(7) If the PCV valve was removed, apply Mopart
Thread Sealant with Teflon to threads and install
valve to cylinder head cover. Tighten PCV valve to 8
N´m (70 in. lbs.).
(8) Connect PCV and make-up air hoses to cylin-
der head cover.
INTAKE/EXHAUST VALVES &
SEATS
DESCRIPTION
The four valves per cylinder are opened by using
roller rocker arms which pivot on hydraulic lash
adjusters. The valves have chrome plated valve
stems. Viton rubber valve stem seals are integral
with the spring seats.They have chrome plated stems
to prevent scuffing. Viton rubber valve stem seals are
integral with the spring seats. The valves, spring
retainers,and locks, are the 3 - bead lock design
CLEANING
(1) Clean all valves thoroughly and discard
burned, warped and cracked valves.
VALVE SPRINGS
REMOVAL
REMOVAL - CYLINDER HEAD ON
(1) Remove camshafts.
(2) Rotate crankshaft until piston is at TDC on
compression.
(3) With air hose attached to adapter tool installed
in spark plug hole, apply 90-120 psi air pressure.
(4) Using Special Tool MD-998772-A with adapter
6779 (Fig. 26), compress valve springs and remove
valve locks.
(5) Remove valve spring(s).
(6) Remove valve stem seal(s) by a using valve
stem seal tool (Fig. 28).
REMOVAL - CYLINDER HEAD OFF
(1) With cylinder head removed from cylinder
block, compress valve springs using a universal valve
spring compressor.
(2) Remove valve retaining locks, valve spring
retainers, valve stem seals and valve springs.
(3) Before removing valves,remove any burrs
from valve stem lock grooves to prevent dam-
age to the valve guides.Identify valves, locks and
retainers to insure installation in original location.
(4) Inspect the valves. (Refer to 9 - ENGINE/CYL-
INDER HEAD/VALVE SPRINGS - INSPECTION)
Fig. 25 CYLINDER HEAD TIGHTENING SEQUENCE
Fig. 26 Valve Spring - Removal/Installation
1 - VALVE SPRING COMPRESSOR MD 998772A
2 - AIR HOSE
KJENGINE9s-27
CYLINDER HEAD COVER (Continued)

(2) Insufficient running time after rebuilding cylin-
der head. Low speed running up to 1 hour may be
required.
(3) During this time, turn engine off and let set for
a few minutes before restarting. Repeat this several
times after engine has reached normal operating
temperature.
(4) Low oil pressure.
(5) The oil restrictor (integral to the head gasket)
in the vertical oil passage to the cylinder head is
plugged with debris.
(6) Air ingested into oil due to broken or cracked
oil pump pick up.
(7) Worn valve guides.
(8) Rocker arm ears contacting valve spring
retainer.
(9) Rocker arm loose, adjuster stuck or at maxi-
mum extension and still leaves lash in the system.
(10) Faulty lash adjuster.
a. Check lash adjusters for sponginess while
installed in cylinder head. Depress part of rocker
arm over adjuster. Normal adjusters should feel very
firm. Spongy adjusters can be bottomed out easily.
b. Remove suspected lash adjusters, and replace as
necessary.
REMOVAL
NOTE: This procedure is for in-vehicle service with
camshafts installed.
(1) Remove cylinder head cover. (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL)
(2) Remove the camshafts (Refer to 9 - ENGINE/
CYLINDER HEAD/CAMSHAFT(S) - REMOVAL).
(3) Remove rocker arm. (Refer to 9 - ENGINE/
CYLINDER HEAD/ROCKER ARMS - REMOVAL)
(4) Remove hydraulic lifter (Fig. 30).(5) Repeat removal procedure for each hydraulic
lifter.
(6) If reusing, mark each hydraulic lifter for reas-
sembly in original position. Lifters are serviced as an
assembly.
INSTALLATION
(1) Install hydraulic lifter (Fig. 30). Ensure the
lifters are at least partially full of engine oil. This is
indicated by little or no plunger travel when the
lifter is depressed.
(2) Install rocker arm. (Refer to 9 - ENGINE/CYL-
INDER HEAD/ROCKER ARMS - INSTALLATION)
(3) Repeat installation procedure for each hydrau-
lic lifter.
(4) Install camshafts (Refer to 9 - ENGINE/CYL-
INDER HEAD/CAMSHAFT(S) - INSTALLATION).
(5) Install cylinder head cover. (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION)
ROCKER ARMS
REMOVAL
NOTE: This procedure is for in-vehicle service with
camshafts installed.
(1) Remove cylinder head cover. (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL)
(2) Remove fuel rail. (Refer to 14 - FUEL SYS-
TEM/FUEL DELIVERY/FUEL RAIL - REMOVAL)
(3) Remove spark plugs.
(4) Rotate engine until the camshaft lobe, on the
follower being removed, is position on its base circle
(heel). Also, the piston should be a minimum of 6.3
mm (0.25 in) below TDC position.
Fig. 29 Checking Spring Installed Height and Valve
Tip Height Dimensions
1 - GARTER SPRING
2 - VALVE SPRING SEAT
3 - CYLINDER HEAD SURFACE
Fig. 30 Hydraulic Lash Adjuster
KJENGINE9s-29
HYDRAULIC LIFTERS (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)

TIMING BELT AND
SPROCKET(S)
REMOVAL
REMOVAL - TIMING BELT
(1) Remove air cleaner upper cover, housing, and
clean air tube.
(2) Raise vehicle on hoist.
(3) Remove accessory drive belts. (Refer to 7 -
COOLING/ACCESSORY DRIVE/BELT TENSION-
ERS - REMOVAL)
(4) Remove crankshaft vibration damper. (Refer to
9 - ENGINE/ENGINE BLOCK/VIBRATION
DAMPER - REMOVAL)
(5) Remove air conditioner/generator belt tensioner
and pulley assembly. (Refer to 7 - COOLING/ACCES-
SORY DRIVE/BELT TENSIONERS - REMOVAL)
(6) Remove timing belt lower front cover bolts and
remove cover. (Refer to 9 - ENGINE/VALVE TIMING/
TIMING BELT / CHAIN COVER(S) - REMOVAL)
(7) Lower vehicle.
(8) Remove bolts attaching timing belt upper front
cover and remove cover. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT / CHAIN COVER(S)
- REMOVAL)
CAUTION: When aligning crankshaft and camshaft
timing marks always rotate engine from crankshaft.
Camshaft should not be rotated after timing belt is
removed. Damage to valve components may occur.
Always align timing marks before removing timing
belt.
(9) Before the removal of the timing belt, rotate
crankshaft until the TDC mark on oil pump housing
aligns with the TDC mark on crankshaft sprocket
(trailing edge of sprocket tooth) (Fig. 95).
NOTE: The crankshaft sprocket TDC mark is
located on the trailing edge of the sprocket tooth.
Failure to align trailing edge of sprocket tooth to
TDC mark on oil pump housing will cause the cam-
shaft timing marks to be misaligned.
(10) Install 6 mm Allen wrench into belt tensioner.
Before rotating the tensioner, insert the long end of a
1/8º or 3 mm Allen wrench into the pin hole on the
front of the tensioner (Fig. 96). While rotating the
tensioner counterclockwise, push in lightly on the
1/8º or 3 mm Allen wrench, until it slides into the
locking hole.
(11) Remove timing belt.
REMOVAL - CRANKSHAFT SPROCKET
(1) Disconnect negative battery cable.
(2) Remove timing belt (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - REMOVAL).
(3) Remove crankshaft sprocket using Special
Tools 6793 and insert C-4685-C2 (Fig. 97).
CLEANING
Do Not attempt to clean a timing belt. If contami-
nation from oil, grease, or coolants have occurred, the
timing belt should be replaced.
Clean all sprockets using a suitable solvent. Clean
all sprocket grooves of any debris.
Fig. 95 Crankshaft and Camshaft Timing
1 - CAMSHAFT TIMING MARKS
2 - CRANKSHAFT TDC MARKS
3 - TRAILING EDGE OF SPROCKET TOOTH
KJENGINE9s-55

(1) Set crankshaft sprocket to TDC by aligning the
sprocket with the arrow on the oil pump housing.
(2) Set camshafts timing marks so that the
exhaust camshaft sprocket is a 1/2 notch below the
intake camshaft sprocket (Fig. 99).
CAUTION: Ensure that the arrows on both camshaft
sprockets are facing up.
(3) Install timing belt. Starting at the crankshaft,
go around the water pump sprocket, idler pulley,
camshaft sprockets and then around the tensioner
(Fig. 100).
(4) Move the exhaust camshaft sprocket counter-
clockwise (Fig. 100) to align marks and take up belt
slack.
(5) Inserta6mmAllen wrench into the hexagon
opening located on the top plate of the belt tensioner
pulley. Rotate the top plateCOUNTERCLOCK-
WISE. The tensioner pulley will move against the
belt and the tensioner setting notch will eventually
start to move clockwise. Watching the movement of
the setting notch, continue rotating the top plate
counterclockwise until the setting notch is aligned
with the spring tang (Fig. 101). Using the allen
wrench to prevent the top plate from moving, torque
the tensioner lock nut to 30 N´m (22 ft. lbs.). Setting
notch and spring tang should remain aligned after
lock nut is torqued.
(6) Remove allen wrench and torque wrench.NOTE: Repositioning the crankshaft to the TDC
position must be done only during the CLOCKWISE
rotation movement. If TDC is missed, rotate a fur-
ther two revolutions until TDC is achieved. DO NOT
rotate crankshaft counterclockwise as this will
make verification of proper tensioner setting impos-
sible.
(7) Once the timing belt has been installed and
tensioner adjusted, rotate the crankshaft CLOCK-
WISE two complete revolutions manually for seating
of the belt, until the crankshaft is repositioned at the
TDC position. Verify that the camshaft and crank-
shaft timing marks are in proper position (Fig. 102).
Fig. 99 Camshaft Sprocket Alignment
1 - CAMSHAFT SPROCKET-EXHAUST
2 - CAMSHAFT SPROCKET-INTAKE
3 - 1/2 NOTCH LOCATION
Fig. 100 Timing Belt - Installation - Typical
1 - ROTATE CAMSHAFT SPROCKET TO TAKE UP BELT SLACK
2 - CAMSHAFT TIMING MARKS 1/2 NOTCH LOCATION
3 - CRANKSHAFT AT TDC
4 - INSTALL BELT IN THIS DIRECTION
KJENGINE9s-57
TIMING BELT AND SPROCKET(S) (Continued)