2003 DODGE RAM engine

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
COVER(S)
REMOVAL
(1) Disconnect the battery negative cable.
(2) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(3) Remove electric cooling fan and fan shroud
assembly.
(4) Remove fan and fan drive assembly (Refer to 7
- COOLING/ENGINE/FAN DRIVE VISCOUS
CLUTCH - REMOVAL).
(5) Disconnect both heater hoses at timing cover.
(6) Disconnect lower radiator hose at engine.
(7) Remove accessory drive belt tensioner assembly
(Fig. 103).
(8) Remove crankshaft damper (Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
REMOVAL).
(9) Remove the generator (Refer to 8 - ELECTRI-
CAL/CHARGING/GENERATOR - REMOVAL).
(10) Remove A/C compressor (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING/A/C COM-
PRESSOR - REMOVAL).
CAUTION: The 3.7L engine uses an anerobic sealer
instead of a gasket to seal the front cover to the
engine block, from the factory. For service, MoparT
Engine RTV sealant must be substituted.NOTE: It is not necessary to remove the water
pump for timing cover removal.
(11) Remove the bolts holding the timing cover to
engine block (Fig. 104).
(12) Remove the timing cover.
Fig. 103 ACCESSORY DRIVE BELT TENSIONER
1 - TENSIONER ASSEMBLY
2 - FASTENER TENSIONER TO FRONT COVER
Fig. 104 TIMING CHAIN COVER FASTENERS
9 - 80 ENGINE - 3.7LDR
IDLER SHAFT (Continued)

INSTALLATION
CAUTION: Do not use oil based liquids to clean tim-
ing cover or block surfaces. Use only rubbing alco-
hol, along with plastic or wooden scrapers. Use no
wire brushes or abrasive wheels or metal scrapers,
or damage to surfaces could result.
(1) Clean timing chain cover and block surface
using rubbing alcohol.
CAUTION: The 3.7L uses a special anerobic sealer
instead of a gasket to seal the timing cover to the
engine block, from the factory. For service repairs,
MoparTEngine RTV must be used as a substitute.
(2) Inspect the water passage o-rings for any dam-
age, and replace as necessary.
(3) Apply MopartEngine RTV sealer to front cover
following the path below usinga3to4mmthick
bead (Fig. 105).
(4) Install cover. Tighten fasteners in sequence as
shown in to 58 N´m (43 ft. lbs.) (Fig. 106).
(5) Install crankshaft damper (Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
INSTALLATION).
(6) Install the A/C compressor (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING/A/C COM-
PRESSOR - INSTALLATION).(7) Install the generator (Refer to 8 - ELECTRI-
CAL/CHARGING/GENERATOR - INSTALLATION).
(8) Install accessory drive belt tensioner assembly
(Refer to 7 - COOLING/ACCESSORY DRIVE/BELT
TENSIONERS - INSTALLATION).
(9) Install radiator upper and lower hoses.
(10) Install both heater hoses.
(11) Install electric fan shroud and viscous fan
drive assembly (Refer to 7 - COOLING/ENGINE/FAN
DRIVE VISCOUS CLUTCH - INSTALLATION).
(12) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(13) Connect the battery negative cable.
TIMING BELT/CHAIN AND
SPROCKETS
REMOVAL
(1) Disconnect negative cable from battery.
(2) Drain cooling system(Refer to 7 - COOLING -
STANDARD PROCEDURE).
(3) Remove right and left cylinder head covers(Re-
fer to 9 - ENGINE/CYLINDER HEAD/CYLINDER
HEAD COVER(S) - REMOVAL).
(4) Remove radiator fan shroud(Refer to 7 - COOL-
ING/ENGINE/RADIATOR FAN - REMOVAL).
(5) Rotate engine until timing mark on crankshaft
damper aligns with TDC mark on timing chain cover
(Fig. 108) and the camshaft sprocket ªV6º marks are
at the 12 o'clock position (#1 TDC exhaust stroke)
(Fig. 107).
(6) Remove power steering pump(Refer to 19 -
STEERING/PUMP - REMOVAL).
(7) Remove access plug from left and right cylinder
heads for access to chain guide fasteners (Fig. 109).
Fig. 105 TIMING COVER SEALANT
1 - TIMING CHAIN COVER
2 - WATER PASSAGE ORING
3 - MOPARTENGINE RTV SEALER
Fig. 106 TIMING CHAIN COVER FASTENERS
DRENGINE - 3.7L 9 - 81
TIMING BELT / CHAIN COVER(S) (Continued)

Fig. 107 CAMSHAFT SPROCKET V6 MARKS, (#1 TDC EXHAUST STROKE)
1 - LEFT CYLINDER HEAD2 - RIGHT CYLINDER HEAD
Fig. 108 Engine Top Dead Center
1 - TIMING CHAIN COVER
2 - CRANKSHAFT TIMING MARKS
Fig. 109 Cylinder Head Access Plugs
1 - RIGHT CYLINDER HEAD ACCESS PLUG
2 - LEFT CYLINDER HEAD ACCESS PLUG
9 - 82 ENGINE - 3.7LDR
TIMING BELT/CHAIN AND SPROCKETS (Continued)

(8) Remove the oil fill housing to gain access to the
right side tensioner arm fastener.
(9) Remove crankshaft damper (Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
REMOVAL) and timing chain cover(Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - REMOVAL).
(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 sensor (Fig. 110).
CAUTION: Care should be taken not to damage
camshaft target wheel. Do not hold target wheel
while loosening or tightening camshaft sprocket.
Do not place the target wheel near a magnetic
source of any kind. A damaged or magnetized tar-
get wheel could cause a vehicle no start condition.CAUTION: Do not forcefully rotate the camshafts or
crankshaft independently of each other. Damaging
intake valve to piston contact will occur. Ensure
negative battery cable is disconnected to guard
against accidental starter engagement.
(13) Remove left and right camshaft sprocket bolts.
(14) While holding the left camshaft steel tube
with Special Tool 8428 Camshaft Wrench, remove the
left camshaft sprocket. Slowly rotate the camshaft
approximately 5 degrees clockwise to a neutral posi-
tion.
(15) While holding the right camshaft steel tube
with Special Tool 8428 Camshaft Wrench, remove the
right camshaft sprocket.
(16) Remove idler sprocket assembly bolt.
(17) Slide the idler sprocket assembly and crank
sprocket forward simultaneously to remove the pri-
mary and secondary chains.
(18) Remove both pivoting tensioner arms and
chain guides.
(19) Remove primary chain tensioner.
INSPECTION
Inspect the following components:
²Sprockets for excessive tooth wear. Some tooth
markings are normal and not a cause for sprocket
replacement.
²Idler sprocket assembly bushing and shaft for
excessive wear.
²Idler sprocket assembly spline joint. The joint
should be tight with no backlash or axial movement.
²Chain guides and tensioner arms. Replace these
parts if grooving in plastic face is more than 1 mm
(0.039 in.) deep. If plastic face is severely grooved or
melted, the tensioner lube jet may be clogged. The
tensioner should be replaced.
²Secondary chain tensioner piston and ratcheting
device. Inspect for evidence of heavy contact between
tensioner piston and tensioner arm. If this condition
exist the tensioner tensioner arm and chain should
be replaced.
²Primary chain tensioner plastic faces. Replace as
required.
Fig. 110 Camshaft Position Sensor
1 - CYLINDER HEAD
2 - CAMSAHFT POSITION SENSOR
3 - SCREW
DRENGINE - 3.7L 9 - 83
TIMING BELT/CHAIN AND SPROCKETS (Continued)

INSTALLATION
(1) Using a vise, lightly compress the secondary
chain tensioner piston until the piston step is flush
with the tensioner body. Using a pin or suitable tool,
release ratchet pawl by pulling pawl back against
spring force through access hole on side of tensioner.
While continuing to hold pawl back, Push ratchet
device to approximately 2 mm from the tensioner
body. Install Special Tool 8514 lock pin into hole on
front of tensioner (Fig. 111). Slowly open vise to
transfer piston spring force to lock pin.
(2) Position primary chain tensioner over oil pump
and insert bolts into lower two holes on tensioner
bracket. Tighten bolts to 28 N´m (250 in. lbs.).
(3) Install right side chain tensioner arm. Install
Torxtbolt. Tighten Torxtbolt to 28 N´m (250 in.
lbs.).
CAUTION: The silver bolts retain the guides to the
cylinder heads and the black bolts retain the guides
to the engine block.(4) Install the left side chain guide. Tighten the
bolts to 28 N´m (250 in. lbs.).
(5) Install left side chain tensioner arm, and Torxt
bolt. Tighten Torxtbolt to 28 N´m (250 in. lbs.).
(6) Install the right side chain guide. Tighten the
bolts to 28 N´m (250 in. lbs.).
(7) Install both secondary chains onto the idler
sprocket. Align two plated links on the secondary
chains to be visible through the two lower openings
on the idler sprocket (4 o'clock and 8 o'clock). Once
the secondary timing chains are installed, position
special tool 8429 to hold chains in place for installa-
tion.
(8) Align primary chain double plated links with
the timing mark at 12 o'clock on the idler sprocket.
Align the primary chain single plated link with the
timing mark at 6 o'clock on the crankshaft sprocket.
(9) Lubricate idler shaft and bushings with clean
engine oil.
NOTE: The idler sprocket must be timed to the
counterbalance shaft drive gear before the idler
sprocket is fully seated.
Fig. 111 RESETTING SECONDARY CHAIN
TENSIONERS
1 - VISE
2 - INSERT LOCK PIN
3 - RATCHET PAWL
4 - RATCHET
5 - PISTON
Fig. 112 INSTALLING IDLER GEAR, PRIMARY AND
SECONDARY TIMING CHAINS
1 - SPECIAL TOOL 8429
2 - PRIMARY CHAIN IDLER SPROCKET
3 - CRANKSHAFT SPROCKET
9 - 84 ENGINE - 3.7LDR
TIMING BELT/CHAIN AND SPROCKETS (Continued)

(10) Install all chains, crankshaft sprocket, and
idler sprocket as an assembly (Fig. 112). After guid-
ing both secondary chains through the block and cyl-
inder head openings, affix chains with a elastic strap
or equivalent. This will maintain tension on chains to
aid in installation. Align the timing mark on the
idler sprocket gear to the timing mark on the coun-
terbalance shaft drive gear, then seat idler sprocket
fully (Fig. 113). Before installing idler sprocket bolt,
lubricate washer with oil, and tighten idler sprocket
assembly retaining bolt to 34 N´m (25 ft. lbs.).
NOTE: It will be necessary to slightly rotate cam-
shafts for sprocket installation.
(11) Align left camshaft sprocket ªLº dot to plated
link on chain.
(12) Align right camshaft sprocket ªRº dot to
plated link on chain.
CAUTION: Remove excess oil from the camshaft
sprocket bolt. Failure to do so can result in over-
torque of bolt resulting in bolt failure.
(13) Remove Special Tool 8429, then attach both
sprockets to camshafts. Remove excess oil from bolts,
then Install sprocket bolts, but do not tighten at this
time.(14) Verify that all plated links are aligned with
the marks on all sprockets and the ªV6º marks on
camshaft sprockets are at the 12 o'clock position.
CAUTION: Ensure the plate between the left sec-
ondary chain tensioner and block is correctly
installed.
(15) Install both secondary chain tensioners.
Tighten bolts to 28 N´m (250 in. lbs.).
NOTE: Left and right secondary chain tensioners
are not common.
(16) Remove all locking pins (3) from tensioners.
CAUTION: After pulling locking pins out of each
tensioner, DO NOT manually extend the tensioner(s)
ratchet. Doing so will over tension the chains,
resulting in noise and/or high timing chain loads.
(17) Using Special Tool 6958, Spanner with Adap-
tor Pins 8346, tighten left (Fig. 114) and right (Fig.
115). camshaft sprocket bolts to 122 N´m (90 ft. lbs.).
Fig. 113 COUNTERBALANCE SHAFT ALIGNMENT
MARKS
1 - COUNTERBALANCE SHAFT GEAR
2 - TIMING MARK
3 - IDLER SPROCKET GEAR
Fig. 114 TIGHTENING LEFT SIDE CAMSHAFT
SPROCKET BOLT
1 - TORQUE WRENCH
2 - CAMSHAFT SPROCKET
3 - LEFT CYLINDER HEAD
4 - SPECIAL TOOL 6958 SPANNER WITH ADAPTER PINS 8346
DRENGINE - 3.7L 9 - 85
TIMING BELT/CHAIN AND SPROCKETS (Continued)

(18) Rotate engine two full revolutions. Verify tim-
ing marks are at the follow locations:
²primary chain idler sprocket dot is at 12 o'clock
²primary chain crankshaft sprocket dot is at 6
o'clock
²secondary chain camshaft sprockets ªV6º marks
are at 12 o'clock
²counterbalancer shaft drive gear dot is aligned
to the idler sprocket gear dot
(19) Lubricate all three chains with engine oil.
(20) After installing all chains, it is recommended
that the idler gear end play be checked. The end play
must be within 0.10±0.25 mm (0.004±0.010 in.). If
not within specification, the idler gear must be
replaced (Fig. 116).
(21) Install timing chain cover and crankshaft
damper. Refer to procedures.
(22) Install cylinder head covers(Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).NOTE: Before installing threaded plug in right cylin-
der head, the plug must be coated with sealant to
prevent leaks.
(23) Coat the large threaded access plug with
MopartThread Sealant with Teflon, then install
into the right cylinder head and tighten to 81 N´m
(60 ft. lbs.).
(24) Install the oil fill housing.
(25) Install access plug in left cylinder head.
(26) Install power steering pump(Refer to 19 -
STEERING/PUMP - INSTALLATION).
(27) Fill cooling system(Refer to 7 - COOLING -
STANDARD PROCEDURE).
(28) Connect negative cable to battery.
Fig. 115 TIGHTENING RIGHT SIDE CAMSHAFT
SPROCKET BOLT
1 - TORQUE WRENCH
2 - SPECIAL TOOL 6958 WITH ADAPTER PINS 8346
3 - LEFT CAMSHAFT SPROCKET
4 - RIGHT CAMSHAFT SPROCKETFig. 116 MEASURING IDLER GEAR END PLAY
1 - IDLER SPROCKET ASSEMBLY
2 - DIAL INDICATOR
9 - 86 ENGINE - 3.7LDR
TIMING BELT/CHAIN AND SPROCKETS (Continued)

ENGINE - 4.7L
TABLE OF CONTENTS
page page
ENGINE - 4.7L
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - PERFORMANCE...........89
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - MECHANICAL.............91
DIAGNOSIS AND TESTING - CYLINDER
COMPRESSION PRESSURE.............92
DIAGNOSIS AND TESTING - CYLINDER
COMBUSTION PRESSURE LEAKAGE......92
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - INTRODUCTION...........93
STANDARD PROCEDURE
STANDARD PROCEDURE - REPAIR
DAMAGED OR WORN THREADS.........93
STANDARD PROCEDURE - FORM-IN-
PLACE GASKETS AND SEALERS.........93
REMOVAL.............................94
INSTALLATION.........................96
SPECIFICATIONS
4.7L ENGINE.........................98
TORQUE...........................101
SPECIAL TOOLS
4.7L ENGINE........................102
AIR CLEANER ELEMENT
REMOVAL............................105
INSTALLATION........................105
CYLINDER HEAD
DESCRIPTION
DESCRIPTION - CYLINDER HEAD.......106
DESCRIPTION - VALVE GUIDES.........106
REMOVAL
REMOVAL - LEFT CYLINDER HEAD......106
REMOVAL - RIGHT CYLINDER HEAD.....108
CLEANING...........................110
INSPECTION..........................110
INSTALLATION
INSTALLATION - LEFT CYLINDER HEAD . . . 110
INSTALLATION - RIGHT CYLINDER HEAD . . 111
CAMSHAFT(S) - LEFT
DESCRIPTION........................113
REMOVAL............................113
INSTALLATION........................114
CAMSHAFT(S) - RIGHT
DESCRIPTION........................117
REMOVAL............................117
INSTALLATION........................118
CYLINDER HEAD COVER(S)
DESCRIPTION........................121REMOVAL
REMOVAL - RIGHT SIDE...............121
REMOVAL - LEFT SIDE................121
CLEANING...........................121
INSTALLATION
INSTALLATION - RIGHT SIDE...........121
INSTALLATIONÐLEFT SIDE............122
INTAKE/EXHAUST VALVES & SEATS
DESCRIPTION........................122
REMOVAL............................122
INSTALLATION........................123
ROCKER ARM / ADJUSTER ASSEMBLY
DESCRIPTION........................124
DIAGNOSIS AND TESTING - HYDRAULIC
LASH ADJUSTER.....................124
REMOVAL............................124
INSTALLATION........................124
VALVE SPRINGS
DESCRIPTION........................125
REMOVAL............................125
INSTALLATION........................126
VALVE STEM SEALS
DESCRIPTION........................126
ENGINE BLOCK
DESCRIPTION........................126
STANDARD PROCEDUREÐCYLINDER BORE
HONING...........................126
CLEANING...........................127
INSPECTION.........................127
CONNECTING ROD BEARINGS
STANDARD PROCEDURE - CONNECTING
ROD BEARING FITTING...............128
CORE PLUGS
REMOVAL............................129
INSTALLATION........................130
CRANKSHAFT
DESCRIPTION........................130
REMOVAL............................130
INSPECTION.........................131
INSTALLATION........................131
CRANKSHAFT MAIN BEARINGS
STANDARD PROCEDUREÐCRANKSHAFT
MAIN BEARING - FITTING..............133
INSPECTION.........................133
CRANKSHAFT OIL SEAL - FRONT
REMOVAL............................134
INSTALLATION........................134
DRENGINE - 4.7L 9 - 87