1998 DODGE RAM 1500 light

CRANKSHAFT OIL SEAL -
REAR
DIAGNOSIS AND TESTING - REAR SEAL AREA
LEAKS
Since it is sometimes difficult to determine the
source of an oil leak in the rear seal area of the
engine, a more involved inspection is necessary. The
following steps should be followed to help pinpoint
the source of the leak.
If the leakage occurs at the crankshaft rear oil seal
area:
(1) Disconnect the battery.
(2) Raise the vehicle.
(3) Remove torque converter or clutch housing
cover and inspect rear of block for evidence of oil.
Use a black light to check for the oil leak:
(a) Circular spray pattern generally indicates
seal leakage or crankshaft damage.
(b) Where leakage tends to run straight down,
possible causes are a porous block, camshaft bore
cup plugs, oil galley pipe plugs, oil filter runoff,
and main bearing cap to cylinder block mating sur-
faces. See Engine, for proper repair procedures of
these items.
(4) If no leaks are detected, pressurized the crank-
case as outlined in the section, Inspection (Engine oil
Leaks in general)
CAUTION: Do not exceed 20.6 kPa (3 psi).
(5) If the leak is not detected, very slowly turn the
crankshaft and watch for leakage. If a leak is
detected between the crankshaft and seal while
slowly turning the crankshaft, it is possible the
crankshaft seal surface is damaged. The seal area on
the crankshaft could have minor nicks or scratches
that can be polished out with emery cloth.
CAUTION: Use extreme caution when crankshaft
polishing is necessary to remove minor nicks or
scratches. The crankshaft seal flange is specially
machined to complement the function of the rear oil
seal.
(6) For bubbles that remain steady with shaft
rotation, no further inspection can be done until dis-
assembled. (Refer to 9 - ENGINE - DIAGNOSIS AND
TESTING), under the Oil Leak row, for components
inspections on possible causes and corrections.
(7) After the oil leak root cause and appropriate
corrective action have been identified, (Refer to 9 -
ENGINE/ENGINE BLOCK/CRANKSHAFT OIL
SEAL - REAR - REMOVAL).
REMOVAL
NOTE: This procedure can be performed in vehicle.
(1) If being preformed in vehicle, remove the
transmission.
(2) Remove the flexplate (Refer to 9 - ENGINE/
ENGINE BLOCK/FLEX PLATE - REMOVAL).
NOTE: The crankshaft oil seal CAN NOT be reused
after removal.
NOTE: The crankshaft rear oil seal remover Special
Tool 8506 must be installed deeply into the seal.
Continue to tighten the removal tool into the seal
until the tool can not be turned farther. Failure to
install tool correctly the first time will cause tool to
pull free of seal without removing seal from engine.
(3) Using Special Tool 8506 (Fig. 67), remove the
crankshaft rear oil seal.
Fig. 67 Crankshaft Rear Oil Seal Removal
1 - REAR CRANKSHAFT SEAL
2 - SPECIAL TOOL 8506
DRENGINE - 4.7L 9 - 137

PISTON & CONNECTING ROD
DESCRIPTION
CAUTION: Do not use a metal stamp to mark con-
necting rods as damage may result, instead use ink
or a scratch awl.
The pistons are made of a high strength aluminum
alloy. The anodized top ring groove and crown has
been replaced with a coated top ring that is blue in
color on the bottom surface. Piston skirts are coated
with a solid lubricant (Molykote) to reduce friction
and provide scuff resistance. The connecting rods are
made of forged powdered metal, with a ªfractured
capº design. A pressed fit piston pin is used to attach
the piston and connecting rod.
STANDARD PROCEDURE - PISTON FITTING
(1) To correctly select the proper size piston, a cyl-
inder bore gauge, capable of reading in 0.003 mm (
.0001 in.) INCREMENTS is required. If a bore gauge
is not available, do not use an inside micrometer.
(2) Measure the inside diameter of the cylinder
bore at a point 38.0 mm (1.5 inches) below top of
bore. Start perpendicular (across or at 90 degrees) to
the axis of the crankshaft at point A and then take
an additional bore reading 90 degrees to that at point
B (Fig. 72).
(3) The coated pistons will be serviced with the
piston pin and connecting rod pre-assembled.
(4) The coating material is applied to the piston
after the final piston machining process. Measuring
the outside diameter of a coated piston will not pro-
vide accurate results (Fig. 71). Therefore measuring
the inside diameter of the cylinder bore with a dial
Bore Gauge isMANDATORY. To correctly select the
proper size piston, a cylinder bore gauge capable of
reading in 0.003 mm (.0001 in.) increments is
required.
(5) Piston installation into the cylinder bore
requires slightly more pressure than that required
for non-coated pistons. The bonded coating on the
piston will give the appearance of a line-to-line fit
with the cylinder bore.
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove the following components:
²Oil pan and gasket/windage tray (Refer to 9 -
ENGINE/LUBRICATION/OIL PAN - REMOVAL).
²Cylinder head covers (Refer to 9 - ENGINE/
CYLINDER HEAD/CYLINDER HEAD COVER(S) -
REMOVAL) and (Refer to 9 - ENGINE/CYLINDER
HEAD/CYLINDER HEAD COVER(S) - REMOVAL).²Timing chain cover (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT / CHAIN COVER(S)
- REMOVAL).
²Cylinder head(s) (Refer to 9 - ENGINE/CYLIN-
DER HEAD - REMOVAL) and (Refer to 9 - ENGINE/
CYLINDER HEAD - REMOVAL).
(3) If necessary, remove top ridge of cylinder bores
with a reliable ridge reamer before removing pistons
from cylinder block.Be sure to keep tops of pis-
Fig. 71 DO NOT MEASURE MOLY COATED PISTON
1 - MOLY COATED
2 - MOLY COATED
Fig. 72 BORE GAUGE - TYPICAL
1 - FRONT
2 - BORE GAUGE
3 - CYLINDER BORE
4 - 38 MM (1.5 in)
DRENGINE - 4.7L 9 - 139

VIBRATION DAMPER
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(3) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(4) Remove radiator upper hose.
(5) Remove upper fan shroud.
(6) Using Special Tools 6958 Spanner with Adapter
Pins 8346, loosen fan and viscous assembly from
water pump (Fig. 81).
(7) Remove fan and viscous assembly.
(8) Disconnect electrical connector for fan mounted
inside radiator shroud.
NOTE: Transmission cooler line snaps into shroud
lower right hand corner.
(9) Remove crankshaft damper bolt.
(10) Remove damper using Special Tools 8513
Insert and 1026 Three Jaw Puller (Fig. 82).
INSTALLATION
CAUTION: To prevent severe damage to the Crank-
shaft, Damper or Special Tool 8512±A, thoroughlyclean the damper bore and the crankshaft nose
before installing Damper.
(1) Align crankshaft damper slot with key in
crankshaft. Slide damper onto crankshaft slightly.
CAUTION: Special Tool 8512±A, is assembled in a
specific sequence. Failure to assemble this tool in
this sequence can result in tool failure and severe
damage to either the tool or the crankshaft.
(2) Assemble Special Tool 8512±A as follows, The
nut is threaded onto the shaft first. Then the roller
bearing is placed onto the threaded rod (The hard-
ened bearing surface of the bearingMUSTface the
nut). Then the hardened washer slides onto the
threaded rod (Fig. 83). Once assembled coat the
threaded rod's threads with MopartNickel Anti-
Seize or equivalent.
(3) Using Special Tool 8512±A, press damper onto
crankshaft (Fig. 84).
(4) Install then tighten crankshaft damper bolt to
175 N´m (130 ft. lbs.).
(5) Install fan blade assembly (Refer to 7 - COOL-
ING/ENGINE/FAN DRIVE VISCOUS CLUTCH -
INSTALLATION).
(6) Install radiator upper shroud and tighten fas-
teners to 11 N´m (95 in. lbs.).
(7) Connect electrical connector for shroud fan.
(8) Install radiator upper hose.
Fig. 81 FAN ASSEMBLY - REMOVAL/ASSEMBLY
1 - SPECIAL TOOL 6958 SPANNER WRENCH WITH ADAPTER
PINS 8346
2-FAN
Fig. 82 CRANKSHAFT DAMPER - REMOVAL
1 - SPECIAL TOOL 8513 INSERT
2 - SPECIAL TOOL 1026
9 - 144 ENGINE - 4.7LDR

DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - CHECKING
ENGINE OIL PRESSURE
(1) Remove oil pressure sending unit (Fig. 93)and
install gauge assembly C-3292.
(2) Run engine until thermostat opens.
(3) Oil Pressure:
²Curb Idle - 25 kPa (4 psi) minimum
²3000 rpm - 170 - 758 kPa (25 - 110 psi)
(4) If oil pressure is 0 at idle, shut off engine.
Check for a clogged oil pick-up screen or a pressure
relief valve stuck open.
DIAGNOSIS AND TESTING - ENGINE OIL LEAK
Begin with a thorough visual inspection of the
engine, particularly at the area of the suspected leak.
If an oil leak source is not readily identifiable, the
following steps should be followed:
(1) Do not clean or degrease the engine at this
time because some solvents may cause rubber to
swell, temporarily stopping the leak.
(2) Add an oil soluble dye (use as recommended by
manufacturer). Start the engine and let idle for
approximately 15 minutes. Check the oil dipstick to
make sure the dye is thoroughly mixed as indicated
with a bright yellow color under a black light.(3) Using a black light, inspect the entire engine
for fluorescent dye, particularly at the suspected area
of oil leak. If the oil leak is found and identified,
repair per service manual instructions.
(4) If dye is not observed, drive the vehicle at var-
ious speeds for approximately 24 km (15 miles), and
repeat inspection.If the oil leak source is not posi-
tively identified at this time, proceed with the air
leak detection test method.
Air Leak Detection Test Method
(1) Disconnect the breather cap to air cleaner hose
at the breather cap end. Cap or plug breather cap
nipple.
(2) Remove the PCV valve from the cylinder head
cover. Cap or plug the PCV valve grommet.
(3) Attach an air hose with pressure gauge and
regulator to the dipstick tube.
CAUTION: Do not subject the engine assembly to
more than 20.6 kPa (3 PSI) of test pressure.
(4) Gradually apply air pressure from 1 psi to 2.5
psi maximum while applying soapy water at the sus-
pected source. Adjust the regulator to the suitable
test pressure that provide the best bubbles which
will pinpoint the leak source. If the oil leak is
detected and identified, repair per service manual
procedures.
(5) If the leakage occurs at the rear oil seal area,
refer to the section, Inspection for Rear Seal Area
Leak.
(6) If no leaks are detected, turn off the air supply
and remove the air hose and all plugs and caps.
Install the PCV valve and breather cap hose.
(7) Clean the oil off the suspect oil leak area using
a suitable solvent. Drive the vehicle at various
speeds approximately 24 km (15 miles). Inspect the
engine for signs of an oil leak by using a black light.
INSPECTION FOR REAR SEAL AREA LEAKS
Since it is sometimes difficult to determine the
source of an oil leak in the rear seal area of the
engine, a more involved inspection is necessary. The
following steps should be followed to help pinpoint
the source of the leak.
If the leakage occurs at the crankshaft rear oil seal
area:
(1) Disconnect the battery.
(2) Raise the vehicle.
(3) Remove torque converter or clutch housing
cover and inspect rear of block for evidence of oil.
Use a black light to check for the oil leak:
(a) Circular spray pattern generally indicates
seal leakage or crankshaft damage.
(b) Where leakage tends to run straight down,
possible causes are a porous block, distributor seal,
Fig. 93 OIL PRESSURE SENDING UNIT -TYPICAL
1 - BELT
2 - OIL PRESSURE SENSOR
3 - OIL FILTER
4 - ELEC. CONNECTOR
9 - 152 ENGINE - 4.7LDR
LUBRICATION (Continued)

(4) When filter separates from cylinder block oil
filter boss, tip gasket end upward to minimize oil
spill. Remove filter from vehicle.
NOTE: Make sure filter gasket was removed with fil-
ter.
(5) With a wiping cloth, clean the gasket sealing
surface of oil and grime.
INSTALLATION
(1) Lightly lubricate oil filter gasket with engine
oil.
(2) Thread filter onto adapter nipple. When gasket
makes contact with sealing surface, (Fig. 98) hand
tighten filter one full turn, do not over tighten.
(3) Add oil, verify crankcase oil level and start
engine. Inspect for oil leaks.
OIL PAN
REMOVAL
(1) Disconnect the negative battery cable.
(2) Install engine support fixture special tool #
8534.Do not raise engine at this time.
(3) Loosen both left and right side engine mount
through bolts. Do not remove bolts.
(4)
(5) Remove the structural dust cover, if equipped.
(6) Drain engine oil.
(7) Remove the front crossmember(Refer to 13 -
FRAME & BUMPERS/FRAME/FRONT CROSS-
MEMBER - REMOVAL).
CAUTION: Only raise the engine enough to provide
clearance for oil pan removal. Check for proper
clearance at fan shroud to fan and cowl to intake
manifold.(8) Raise engine using special tool # 8534 to pro-
vide clearance to remove oil pan.
NOTE: Do not pry on oil pan or oil pan gasket. Gas-
ket is integral to engine windage tray and does not
come out with oil pan.
(9) Remove the oil pan mounting bolts and oil pan.
(10) Unbolt oil pump pickup tube and remove
tube.
(11) Inspect the integral windage tray and gasket
and replace as needed.
INSTALLATION
(1) Clean the oil pan gasket mating surface of the
bedplate and oil pan.
(2) Position the oil pan gasket and pickup tube
with new o-ring. Install the mounting bolt and nuts.
Tighten bolt and nuts to 28 N´m (20 ft. lbs.).
(3) Position the oil pan and install the mounting
bolts. Tighten the mounting bolts to 15 N´m (11 ft.
lbs.) in the sequence shown (Fig. 99).
(4) Lower the engine into mounts using special
tool # 8534.
(5) Install both the left and right side engine
mount through bolts. Tighten the nuts to 68 N´m (50
ft. lbs.).
(6) Remove special tool # 8534.
(7) Install structural dust cover, if equipped.
(8) Install the front crossmember(Refer to 13 -
FRAME & BUMPERS/FRAME/FRONT CROSS-
MEMBER - INSTALLATION).
(9) Fill engine oil.
(10) Reconnect the negative battery cable.
(11) Start engine and check for leaks.
Fig. 98 Oil Filter Sealing Surface-Typical
1 - SEALING SURFACE
2 - RUBBER GASKET
3 - OIL FILTER
Fig. 99 Oil Pan Mounting Bolts and Oil Pan
DRENGINE - 4.7L 9 - 155
OIL FILTER (Continued)

EXHAUST MANIFOLD
DESCRIPTION
The exhaust manifolds are log style with a pat-
ented flow enhancing design to maximize perfor-
mance. The exhaust manifolds are made of high
silicon molybdenum cast iron. A perforated core
graphite exhaust manifold gasket is used to improve
sealing to the cylinder head. The exhaust manifolds
are covered by a three layer laminated heat shield
for thermal protection and noise reduction. The heat
shields are fastened with a torque prevailing nut
that is backed off slightly to allow for the thermal
expansion of the exhaust manifold.
REMOVAL
RIGHT EXHAUST MANIFOLD
(1) Disconnect negative cable for battery.
(2) Remove air cleaner assembly, resonator assem-
bly and air inlet hose.
(3) Remove accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(4) Remove A/C compressor (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING/A/C COM-
PRESSOR - REMOVAL).
(5) Remove A/C accumulator support bracket fas-
tener.(6) Drain coolant below heater hose level (Refer to
7 - COOLING - STANDARD PROCEDURE).
(7) Remove heater hoses at engine.
(8) Remove fasteners attaching exhaust manifold
heat shield.
(9) Remove heat shield.
(10) Remove upper exhaust manifold attaching fas-
teners.
(11) Raise vehicle on hoist.
(12) Disconnect exhaust pipe from manifold.
(13) Remove fasteners attaching starter. Move
starter aside.
(14) Remove lower exhaust manifold attaching fas-
teners.
(15) Remove exhaust manifold and gasket (Fig.
110). Manifold is removed from below the engine
compartment.
DRENGINE - 4.7L 9 - 161

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. Slowly open vise to transfer piston
spring force to lock pin (Fig. 134).
(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.).
CAUTION: Overtightening the tensioner arm torxT
bolt can cause severe damage to the cylinder head.
Tighten torxTbolt to specified torque only.
(3) Install right side chain tensioner arm. Apply
MopartLock N, Seal to torxtbolt, tighten bolt to 17
N´m (150 in. lbs.).
NOTE: The silver bolts retain the guides to the cyl-
inder 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.).
CAUTION: Overtightening the tensioner arm torxT
bolt can cause severe damage to the cylinder head.
Tighten torxTbolt to specified torque only.
(5) Install left side chain tensioner arm. Apply
MopartLock N, Seal to torxtbolt, tighten bolt to 17
N´m (150 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 8515 to hold chains in place for installa-
tion (Fig. 135).
(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
(Fig. 133).
Fig. 134 Resetting Secondary Chain Tensioners
1 - VISE
2 - INSERT LOCK PIN
3 - RATCHET PAWL
4 - RATCHET
5 - PISTON
Fig. 135 Installing Secondary Timing Chains on
Idler Sprocket
1 - LOCK ARM
2 - RIGHT CAMSHAFT CHAIN
3 - SECONDARY CHAINS RETAINING PINS (4)
4 - IDLER SPROCKET
5 - LEFT CAMSHAFT CHAIN
6 - SPECIAL TOOL 8515
9 - 176 ENGINE - 4.7LDR
TIMING BELT/CHAIN AND SPROCKETS (Continued)

(9) Lubricate idler shaft and bushings with clean
engine oil.
(10) Install all chains, crankshaft sprocket, and
idler sprocket as an assembly (Fig. 136). After guid-
ing both secondary chains through the block and cyl-
inder head openings, affix chains with a elastic strap
or the equivalent, This will maintain tension on
chains to aid in installation.
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 8515, 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 ªV8º marks on
camshaft sprockets are at the 12 o'clock position (Fig.
133).
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) Before installing idler sprocket bolt, lubricate
washer with oil, and tighten idler sprocket assembly
retaining bolt to 34 N´m (25 ft. lbs.).
(17) 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.
(18) Using Special Tool 6958, Spanner with Adap-
tor Pins 8346, tighten left (Fig. 137) and right (Fig.
138). camshaft sprocket bolts to 122 N´m (90 ft. lbs.).
Fig. 136 Installing Idler Gear, Primary and
Secondary Timing Chains
1 - SPECIAL TOOL 8515
2 - PRIMARY CHAIN IDLER SPROCKET
3 - CRANKSHAFT SPROCKET
Fig. 137 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 - 4.7L 9 - 177
TIMING BELT/CHAIN AND SPROCKETS (Continued)