1998 DODGE RAM 1500 Camshaft specification

OIL PRESSURE
SPECIFICATION SPECIFICATION
Metric Standard
At Curb Idle
Speed (MIN)*25 kPa 4 psi
@ 3000 rpm 170 - 758 kPa 25 - 110 psi
* CAUTION: If pressure is zero at curb idle, DO
NOT run engine at 3000 rpm.
TORQUE
DESCRIPTION N´m Ft.
Lbs.In.
Lbs.
Camshaft
Non - Oiled Sprocket Bolt 122 90 -
Bearing Cap Bolts 11 - 100
Counterbalance shaft
retaining bolt28 - 250
Timing Chain Cover-Bolts 58 43 -
Connecting Rod Cap-Bolts 27 20 -
PLUS 90É TURN
Bed Plate-Bolts Refer to Procedure
Crankshaft Damper-Bolt 175 130 -
Cylinder Head-Bolts
M11 Bolts Refer To Procedure
M8 Bolts Refer To Procedure
Cylinder Head Cover-Bolts 12 - 105
Exhaust Manifold-Bolts 25 18 -
Exhaust Manifold Heat
Shield-Nuts8-72
Then loosen 45É
DESCRIPTION N´m Ft.
Lbs.In.
Lbs.
Flexplate-Bolts 95 70 -
Engine Mount Bracket to
Block-Bolts61 45 -
Rear Mount to Transmission-
Bolts46 34 -
Generator Mounting-Bolts
M10 Bolts 54 40 -
M8 Bolts 28 - 250
Intake Manifold-Bolts 12 - 105
Refer to Procedure
for Tightening
Sequence
Oil Pan-Bolts 15 - 130
Oil Pan-Drain Plug 34 25 -
Oil Pump-Bolts 28 - 250
Oil Pump Cover-Bolts 12 - 105
Oil Pickup Tube-Bolt and Nut 28 - 250
Oil Dipstick Tube to Engine
Block-Bolt15 - 130
Oil Fill Tube-Bolts 12 - 105
Timing Chain Guide-Bolts 28 - 250
Timing Chain Tensioner Arm 28 - 250
Hydraulic Tensioner-Bolts 28 - 250
Timing Chain Primary
Tensioner-Bolts28 - 250
Timing Drive Idler Sprocket-
Bolt34 25 -
Thermostat Housing-Bolts 12 - 105
Water Pump-Bolts 58 43 -
9 - 16 ENGINE - 3.7LDR
ENGINE - 3.7L (Continued)

TESTING VALVE SPRINGS
NOTE: Whenever the valves are removed from the
cylinder head it is recommended that the valve
springs be inspected and tested for reuse.
Inspect the valve springs for physical signs of wear or
damage. Turn table of tool C-647 until surface is in line
with the 40.12 mm (1.579 in.) mark on the threaded
stud and the zero mark on the front. Place spring over
the stud on the table and lift compressing lever to set
tone device. Pull on torque wrench until a Ping is
heard. Take reading on torque wrench at this instant.
Multiply this reading by two. This will give the spring
load at test length. Fractional measurements are indi-
cated on the table for finer adjustments. Refer to Spec-
ifications Section to obtain specified height and
allowable tensions. Replace any springs that do not
meet specifications (Fig. 19).
INSTALLATION
(1) coat the valve stem with clean engine oil and
insert it into the cylinder head.
(2) Install the valve stem seal. make sure the seal
is fully seated and that the garter spring at the top
of the seal is intact.
(3) Install the spring and the spring retainer (Fig.
20).
(4) Using the valve spring compressor, compress
the spring and install the two valve spring retainer
halves.
(5) Release the valve spring compressor and make
sure the two spring retainer halves and the spring
retainer are fully seated.
(6) lubricate the camshaft journal with clean
engine oil then Position the camshaft (with the
sprocket dowel on the left camshaft at 11 o'clock and
the right camshaft at 12 o'clock), then position the
camshaft bearing caps.(7) Install the camshaft bearing cap retaining
bolts. Tighten the bolts 9-13 N´m (100 in. lbs.) in 1/2
turn increments in the sequence shown (Fig. 21).
(8)
Position the hydraulic lash adjusters and rocker
arms(Refer to 9 - ENGINE/CYLINDER HEAD/ROCKER
ARM / ADJUSTER ASSY - INSTALLATION).
Fig. 19 Testing Valve Springs
1 - SPECIAL TOOL C-647
Fig. 20 Valve Assembly Configuration
1 - VALVE LOCKS (3±BEAD)
2 - RETAINER
3 - VALVE STEM OIL SEAL
4 - INTAKE VALVE
5 - EXHAUST VALVE
6 - VALVE SPRING
Fig. 21 Camshaft Bearing Caps Tightening
Sequence
9 - 30 ENGINE - 3.7LDR
INTAKE/EXHAUST VALVES & SEATS (Continued)

block. A large washer on the idler shaft bolt and the
rear flange of the idler shaft are used to control
sprocket thrust movement. Pressurized oil is routed
through the center of the idler shaft to provide lubri-
cation for the two bushings used in the idler sprocket
assembly.
There are two secondary drive chains, both are
roller type, one to drive the camshaft in each SOHC
cylinder head. There are no shaft speed changes in
the secondary chain drive system. Each secondary
chain drives a 26 tooth cam sprocket directly from
the 26 tooth sprocket on the idler sprocket assembly.
A fixed chain guide and a hydraulic oil damped ten-
sioner are used to maintain tension in each second-
ary chain system. The hydraulic tensioners for the
secondary chain systems are fed pressurized oil from
oil reservoir pockets in the block. Each tensioner
incorporates a controlled leak path through a device
known as a vent disc located in the nose of the piston
to manage chain loads. Each tensioner also has a
mechanical ratchet system that limits chain slack if
the tensioner piston bleeds down after engine shut
down. The tensioner arms and guides also utilize
nylon wear faces for low friction and long wear. The
secondary timing chains receive lubrication from a
small orifice in the tensioners. This orifice is pro-
tected from clogging by a fine mesh screen which is
located on the back of the hydraulic tensioners.
STANDARD PROCEDURE
MEASURING TIMING CHAIN WEAR
NOTE: This procedure must be performed with the
timing chain cover removed.
(1) Remove the timing chain cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT/CHAIN
AND SPROCKETS - REMOVAL).
(2) To determine if the secondary timing chains
are worn, rotate the engine clockwise until maximum
tensioner piston extension is obtained. Measure the
distance between the secondary timing chain ten-
sioner housing and the step ledge on the piston. The
measurement at point (A) must be less than 15mm
(.5906 inches) (Fig. 95).
(3) If the measurement exceeds the specification
the secondary timing chains are worn and require
replacement (Refer to 9 - ENGINE/VALVE TIMING/
TIMING BELT/CHAIN AND SPROCKETS -
REMOVAL).
SERVICE PROCEDURE - TIMING VERIFICATION
CAUTION: The 3.7L is a non free-wheeling design
engine. Therefore, correct engine timing is critical.
NOTE: Components referred to as left hand or right
hand are as viewed from the drivers position inside
the vehicle.
NOTE: The blue link plates on the chains and the
dots on the camshaft drive sprockets may not line
up during the timing verification procedure. The
blue link plates are lined up with the sprocket dots
only when re-timing the complete timing drive.
Once the timing drive is rotated blue link-to-dot
alignment is no longer valid.
Engine base timing can be verified by the following
procedure:
(1) Remove the cylinder head covers. Refer to the
procedure in this section.
Fig. 95 Measuring Secondary Timing Chains For
Wear
1 - SECONDARY TENSIONER ARM
2 - SECONDARY CHAIN TENSIONER PISTON
DRENGINE - 3.7L 9 - 77
VALVE TIMING (Continued)

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
DRENGINE - 3.7L 9 - 87
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...........90
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - MECHANICAL.............92
DIAGNOSIS AND TESTING - CYLINDER
COMPRESSION PRESSURE.............93
DIAGNOSIS AND TESTING - CYLINDER
COMBUSTION PRESSURE LEAKAGE......93
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - INTRODUCTION...........94
STANDARD PROCEDURE
STANDARD PROCEDURE - REPAIR
DAMAGED OR WORN THREADS.........94
STANDARD PROCEDURE - FORM-IN-
PLACE GASKETS AND SEALERS.........94
REMOVAL.............................95
INSTALLATION.........................97
SPECIFICATIONS
SPECIFICATIONS - 4.7L ENGINE.........99
TORQUE...........................102
SPECIAL TOOLS
4.7L ENGINE........................103
AIR CLEANER ELEMENT
REMOVAL............................107
INSTALLATION........................107
CYLINDER HEAD
DESCRIPTION
DESCRIPTION - CYLINDER HEAD.......107
DESCRIPTION - VALVE GUIDES.........107
REMOVAL
REMOVAL - LEFT CYLINDER HEAD......108
REMOVAL - RIGHT CYLINDER HEAD.....110
CLEANING...........................111
INSPECTION..........................111
INSTALLATION
INSTALLATION - LEFT CYLINDER HEAD . . . 112
INSTALLATION - RIGHT CYLINDER HEAD . 113
CAMSHAFT(S) - LEFT
DESCRIPTION........................114
REMOVAL............................115
INSTALLATION........................116
CAMSHAFT(S) - RIGHT
DESCRIPTION........................119
REMOVAL............................119
INSTALLATION........................120
CYLINDER HEAD COVER(S)
DESCRIPTION........................122REMOVAL
REMOVAL - RIGHT SIDE...............122
REMOVAL - LEFT SIDE................122
CLEANING...........................123
INSTALLATION
INSTALLATION - RIGHT SIDE...........123
INSTALLATIONÐLEFT SIDE............123
INTAKE/EXHAUST VALVES & SEATS
DESCRIPTION........................123
REMOVAL............................124
INSTALLATION........................124
ROCKER ARM / ADJUSTER ASSEMBLY
DESCRIPTION........................125
DIAGNOSIS AND TESTING - HYDRAULIC
LASH ADJUSTER.....................125
REMOVAL............................126
INSTALLATION........................126
VALVE SPRINGS
DESCRIPTION........................126
REMOVAL............................126
INSTALLATION........................127
VALVE STEM SEALS
DESCRIPTION........................127
ENGINE BLOCK
DESCRIPTION........................128
STANDARD PROCEDURE - CYLINDER BORE
HONING...........................128
CLEANING...........................128
INSPECTION.........................128
CONNECTING ROD BEARINGS
STANDARD PROCEDURE - CONNECTING
ROD BEARING FITTING...............129
CORE PLUGS
REMOVAL............................131
INSTALLATION........................131
CRANKSHAFT
DESCRIPTION........................131
REMOVAL............................131
INSPECTION.........................132
INSTALLATION........................132
CRANKSHAFT MAIN BEARINGS
STANDARD PROCEDUREÐCRANKSHAFT
MAIN BEARING - FITTING..............134
INSPECTION.........................135
CRANKSHAFT OIL SEAL - FRONT
REMOVAL............................135
INSTALLATION........................136
9 - 88 ENGINE - 4.7LDR

Position both the left and right side engine mount
brackets and install the through bolts and nuts.
Tighten nuts to4X2 vehicles95 N´m (70 ft. lbs.).
4X4 vehicles102 N´m (75 ft. lbs.).
(2)4X4 vehiclesInstall locknuts onto the engine
mount brackets. Tighten locknuts to 41 N´m (30 ft.
lbs.).
(3) Remove jack from under the transmission.
(4) Remove Engine Lifting Fixture Special Tool
8347 (Fig. 4).
(5) Remove Special Tools 8400 Lifting Studs.
(6) Position generator wiring behind the oil dip-
stick tube, then install the oil dipstick tube upper
mounting bolt.
(7) Connect both left and right side body ground
straps.
(8) Install power steering pump.
(9) Connect fuel supply line quick connect fitting
(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY/
QUICK CONNECT FITTING - STANDARD PROCE-
DURE).
(10) Connect the vacuum lines at the throttle body
and intake manifold.
(11) Connect engine harness at the following
points (Fig. 3):
²Intake Air Temperature (IAT) Sensor
²Idle Air Control (IAC) Motor
²Fuel Injectors
²Throttle Position (TPS) Switch
²Engine Oil Pressure Switch
²Engine Coolant Temperature (ECT) Sensor
²Manifold Absolute Pressure (MAP) Sensor
²Camshaft Position (CMP) Sensor
²Coil Over Plugs
(12) Position and install heater hoses and tubes
onto intake manifold.
(13) Install the heater hoses onto the heater core
and the engine front cover.
(14) Install generator (Refer to 8 - ELECTRICAL/
CHARGING/GENERATOR - INSTALLATION).
(15) Install A/C condenser (Refer to 24 - HEATING
& AIR CONDITIONING/PLUMBING/A/C CON-
DENSER - INSTALLATION), radiator (Refer to 7 -
COOLING/ENGINE/RADIATOR - INSTALLATION)
and transmission oil cooler.
(16) Connect radiator upper and lower hoses.
(17) Connect the transmission oil cooler lines to
the radiator.
(18) Install accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -INSTALLATION), fan assembly and shroud (Refer to
7 - COOLING/ENGINE/FAN DRIVE VISCOUS
CLUTCH - INSTALLATION).
(19) Install A/C compressor (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING/A/C COM-
PRESSOR - INSTALLATION).
(20) Install both breathers. Connect tube to both
crankcase breathers (Fig. 2).
(21) Connect throttle and speed control cables.
(22) Install throttle body resonator assembly and
air inlet hose. Tighten clamps 4 N´m (35 in. lbs.).
(23) Raise vehicle.
(24) Install transmission to engine mounting bolts.
Tighten the bolts to 41 N´m (30 ft. lbs.).
(25) Install torque converter bolts (Automatic
Transmission Only).
(26) Connect crankshaft position sensor (Fig. 1).
(27)4X4 vehiclesPosition and install the axle
isolator bracket onto the axle, transmission and
engine block. Tighten bolts to specification (Refer to 9
- ENGINE - SPECIFICATIONS).
(28) Install starter (Refer to 8 - ELECTRICAL/
STARTING/STARTER MOTOR - INSTALLATION).
CAUTION: The structural cover requires a specific
torque sequence. Failure to follow this sequence
may cause severe damage to the cover.
(29) Install structural cover (Refer to 9 - ENGINE/
ENGINE BLOCK/STRUCTURAL COVER - INSTAL-
LATION).
(30) Install exhaust crossover pipe.
(31) Install engine block heater power cable, If
equipped.
(32)4X4 vehiclesConnect axle vent tube to left
side engine mount.
(33) Lower vehicle.
(34) Check and fill engine oil.
(35) Recharge the A/C system (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING/REFRIG-
ERANT - STANDARD PROCEDURE).
(36) Refill the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(37) Install the battery tray and battery.
(38) Connect the battery positive and negative
cables.
(39) Start the engine and check for leaks.
9 - 98 ENGINE - 4.7LDR
ENGINE - 4.7L (Continued)

CONNECTING RODS
DESCRIPTION SPECIFICATION
Metric Standard
Bearing
Clearance0.015 - 0.055
mm0.0006 - 0.0022
in.
Side Clearance 0.10 - 0.35 mm 0.004 - 0.0138
in.
Piston Pin Bore
Diameter.025 - .048 mm
(Interference
Fit)0.001 - 0.0019
in.
Bearing Bore
Out of Round
(MAX)0.004 mm 0.0002 in.
Total Weight
(Less Bearing)555 grams 19.5771 ounces
CRANKSHAFT
DESCRIPTION SPECIFICATION
Metric Standard
Main Bearing
Journal
Diameter63.488 - 63.512
mm2.4996 - 2.5005
in.
Bearing
Clearance0.018 - 0.052
mm0.0008 - 0.0021
in.
Out of Round
(MAX)0.005 mm 0.0004 in.
Taper (MAX) 0.008 mm 0.0004 in.
End Play 0.052 - 0.282
mm0.0021 - 0.0112
in.
End Play (MAX) 0.282 mm 0.0112 in.
Connecting Rod
Journal
Diameter50.992 - 51.008
mm2.0076 - 2.0082
in.
Bearing
Clearance0.015 - 0.055 0.0006 - 0.0022
in.
Out of Round
(MAX)0.005 mm 0.0002 in.
Taper (MAX) 0.008 mm 0.0004 in.
CAMSHAFT
DESCRIPTION SPECIFICATION
Metric Standard
Bore Diameter 26.02 - 26.04
mm1.0245 - 1.0252
in.
Bearing Journal
Diameter25.975 - 25.995
mm1.0227 - 1.0235
in.
Bearing
Clearance0.025 - 0.065
mm0.001 - 0.0026
in.
Bearing
Clearance
(MAX)0.065 mm 0.0026 in.
End Play .075 - .200 mm 0.003 - 0.0079
in.
End Play (MAX) .200 mm 0.0079 in.
VALVE TIMING
DESCRIPTION SPECIFICATION
Intake
Opens (BTDC) 4.4É
Closes (ATDC) 239.1É
Duration 243.5É
Exhaust
Opens (BTDC) 240.5É
Closes (ATDC) 13.2É
Duration 253.70É
Valve Overlap 17.6É
9 - 100 ENGINE - 4.7LDR
ENGINE - 4.7L (Continued)

CYLINDER HEAD
DESCRIPTION SPECIFICATION
Gasket Thickness
(Compressed)0.7 mm (0.0276 in.)
Valve Seat Angle 44.5É - 45.0É
Valve Seat Runout (MAX) 0.051 mm (0.002 in.)
Valve Seat Width
Intake 1.75 - 2.36 mm
(0.0698 - 0.0928 in.)
Exhaust 1.71 - 2.32 mm
(0.0673 - 0.0911 in.)
Guide Bore Diameter
(Std.)6.975 - 7.00 mm
(0.2747 - 0.2756 in.)
Cylinder Head Warpage
(Flatness)0.0508 mm (0.002 in.)
OIL PUMP
DESCRIPTION SPECIFICATION
Clearance Over
Rotors/End Face (MAX)0.095 mm (0.0038 in.)
Cover Out - of -Flat
(MAX)0.025 mm (0.001 in.)
Inner and Outer Rotor
Thickness12.02 mm (0.4731 in.)
Outer Rotor to pocket
(Diametral) clearance
(MAX).235 mm (.0093 in.)
Outer Rotor Diameter
(MIN)85.925 mm (0.400 in.)
Tip Clearance Between
Rotors (MAX)0.150 mm (0.006 in.)
OIL PRESSURE
SPECIFICATION SPECIFICATION
At Curb Idle Speed
(MIN)*48 kPa (7 psi)
@ 3000 rpm 240 - 725 kPa (35 - 105
psi)
* CAUTION: If pressure is zero at curb idle, DO
NOT run engine at 3000 rpm.
TORQUE
DESCRIPTION N´m Ft. In.
Lbs. Lbs.
Camshaft
Non - Oiled Sprocket Bolt 122 90 Ð
Bearing Cap Bolts 11 Ð 100
Timing Chain CoverÐBolts 58 43 Ð
Connecting Rod CapÐBolts 27 20 Ð
PLUS 90É TURN
Bed PlateÐBolts Refer to Procedure
Crankshaft DamperÐBolt 175 130 Ð
Cylinder HeadÐBolts
M11 Bolts 81 60 Ð
M8 Bolts 26 19 Ð
Cylinder Head CoverÐBolts 12 Ð 105
Exhaust ManifoldÐBolts 25 18 Ð
Exhaust Manifold Heat
ShieldÐNuts8Ð72
Then loosen 45É
FlexplateÐBolts 60 45 Ð
Engine Mount Bracket to
BlockÐBolts61 45 Ð
Rear Mount to
TransmissionÐBolts46 34 Ð
Generator MountingÐBolts
M10 Bolts 54 40 Ð
M8 Bolts 28 Ð 250
Intake ManifoldÐBolts 12 Ð 105
Refer to Procedure
for
Tightening Sequence
Oil PanÐBolts 15 Ð 130
Oil PanÐDrain Plug 34 25 Ð
Oil PumpÐBolts 28 Ð 250
Oil Pump CoverÐBolts 12 Ð 105
Oil Pickup TubeÐBolt and
Nut28 Ð 250
Oil Dipstick Tube to Engine
BlockÐBolt 15 Ð 130
Oil Fill TubeÐBolts 12 Ð 105
Timing Chain GuideÐBolts 28 Ð 250
Timing Chain Tensioner
ArmÐSpecial
9 - 102 ENGINE - 4.7LDR
ENGINE - 4.7L (Continued)