2003 DODGE RAM light

CRANKSHAFT REAR OIL SEAL
RETAINER
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove the transmission.
(3) Remove the drive plate / flywheel.
(4) Remove the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - REMOVAL).
(5) Remove the rear oil seal retainer mounting
bolts.
(6) Carefully remove the retainer from the engine
block.
INSTALLATION
(1) Throughly clean all gasket resdue from the
engine block.
(2) Use extream care and clean all gasket resdue
from the retainer.
(3) Apply a small amount of MopartSilicone Rub-
ber Adhesive Sealant to the retainer gasket. Position
the gasket onto the retainer.
(4) Position Special Tool 6687 Seal Guide onto the
crankshaft.
(5) Position the retainer and seal over the guide
and onto the engine block.
(6) Install the retainer mounting bolts. Tighten the
bolts to 22 N´m (16 ft. lbs.).
(7) Install the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - INSTALLATION).
(8) Install the drive plate / flywheel.
(9) Install the transmission.
(10) Check and verify engine oil level.
(11) Start engine and check for leaks.
HYDRAULIC LIFTERS
DIAGNOSIS AND TESTINGÐHYDRAULIC
TAPPETS
Before disassembling any part of the engine to cor-
rect tappet noise, check the oil pressure. If vehicle
has no oil pressure gauge, install a reliable gauge at
the pressure sending-unit. The pressure should be
between 207-552 kPa (30-80 psi) at 3,000 RPM.
Check the oil level after the engine reaches normal
operating temperature. Allow 5 minutes to stabilize
oil level, check dipstick. The oil level in the pan
should never be above the FULL mark or below the
ADD OIL mark on dipstick. Either of these two con-
ditions could be responsible for noisy tappets.
OIL LEVEL
HIGH
If oil level is above the FULL mark, it is possible
for the connecting rods to dip into the oil. With the
engine running, this condition could create foam in
the oil pan. Foam in oil pan would be fed to the
hydraulic tappets by the oil pump causing them to
lose length and allow valves to seat noisily.
LOW
Low oil level may allow oil pump to take in air.
When air is fed to the tappets, they lose length,
which allows valves to seat noisily. Any leaks on
intake side of oil pump through which air can be
drawn will create the same tappet action. Check the
lubrication system from the intake strainer to the
pump cover, including the relief valve retainer cap.
When tappet noise is due to aeration, it may be
intermittent or constant, and usually more than one
tappet will be noisy. When oil level and leaks have
been corrected, operate the engine at fast idle. Run
engine for a sufficient time to allow all of the air
inside the tappets to be bled out.
TAPPET NOISE DIAGNOSIS
(1) To determine source of tappet noise, operate
engine at idle with cylinder head covers removed.
(2) Feel each valve spring or rocker arm to detect
noisy tappet. The noisy tappet will cause the affected
spring and/or rocker arm to vibrate or feel rough in
operation.
NOTE: Worn valve guides or cocked springs are
sometimes mistaken for noisy tappets. If such is
the case, noise may be dampened by applying side
thrust on the valve spring. If noise is not apprecia-
bly reduced, it can be assumed the noise is in the
tappet. Inspect the rocker arm push rod sockets
and push rod ends for wear.
(3) Valve tappet noise ranges from light noise to a
heavy click. A light noise is usually caused by exces-
sive leak-down around the unit plunger, or by the
plunger partially sticking in the tappet body cylinder.
The tappet should be replaced. A heavy click is
caused by a tappet check valve not seating, or by for-
eign particles wedged between the plunger and the
tappet body. This will cause the plunger to stick in
the down position. This heavy click will be accompa-
nied by excessive clearance between the valve stem
and rocker arm as valve closes. In either case, tappet
assembly should be removed for inspection and clean-
ing.
9 - 386 ENGINE 8.0LDR

(4) The valve train generates a noise very much
like a light tappet noise during normal operation.
Care must be taken to ensure that tappets are mak-
ing the noise. If more than one tappet seems to be
noisy, it's probably not the tappets.
LEAK-DOWN TEST
After cleaning and inspection, test each tappet for
specified leak-down rate tolerance to ensure zero-lash
operation (Fig. 35).
Swing the weighted arm of the hydraulic valve tap-
pet tester away from the ram of the Universal Leak-
Down Tester.
(1) Place a 7.925-7.950 mm (0.312-0.313 inch)
diameter ball bearing on the plunger cap of the tap-
pet.
(2) Lift the ram and position the tappet (with the
ball bearing) inside the tester cup.
(3) Lower the ram, then adjust the nose of the ram
until it contacts the ball bearing. DO NOT tighten
the hex nut on the ram.
(4) Fill the tester cup with hydraulic valve tappet
test oil until the tappet is completely submerged.
(5) Swing the weighted arm onto the push rod and
pump the tappet plunger up and down to remove air.
When the air bubbles cease, swing the weighted arm
away and allow the plunger to rise to the normal
position.
(6) Adjust the nose of the ram to align the pointer
with the SET mark on the scale of the tester and
tighten the hex nut.
(7) Slowly swing the weighted arm onto the push
rod.
(8) Rotate the cup by turning the handle at the
base of the tester clockwise one revolution every 2
seconds.
(9) Observe the leak-down time interval from the
instant the pointer aligns with the START mark on
the scale until the pointer aligns with the 0.125
mark. A normally functioning tappet will require
20-110 seconds to leak-down. Discard tappets with
leak-down time interval not within this specification.
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Remove the air cleaner.
(3) Remove cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(4) Remove rocker arm assembly and push rods
(Refer to 9 - ENGINE/CYLINDER HEAD/ROCKER
ARM / ADJUSTER ASSY - REMOVAL). Identify
push rods to ensure installation in original location.
(5) Remove upper and lower intake manifold
(Refer to 9 - ENGINE/MANIFOLDS/INTAKE MANI-
FOLD - REMOVAL).(6) Cut the cylinder head gasket for accessibility if
the end tappets are to be removed.
(7) Remove yoke retainer spider and tappet align-
ing yokes (Fig. 36).
Fig. 35 Leak-Down Tester
1 - POINTER
2 - WEIGHTED ARM
3 - RAM
4 - CUP
5 - HANDLE
6 - PUSH ROD
Fig. 36 Tappets, Aligning Yoke and Yoke Retaining
Spider
1 - TAPPET ALIGNING YOLK
2 - YOKE RETAINING SPIDER
3 - TAPPET
DRENGINE 8.0L 9 - 387
HYDRAULIC LIFTERS (Continued)

STANDARD PROCEDUREÐPISTON FITTING
Piston and cylinder wall must be clean and dry.
Specified clearance between the piston and the cylin-
der wall is 0.013-0.038 mm (0.0005-0.0015 inch). The
max. allowable clearance is 0.0762 mm (0.003 in.).
Piston diameter should be measured at the top of
skirt, 90É to piston pin axis. Cylinder bores should be
measured halfway down the cylinder bore and trans-
verse to the engine crankshaft center line.
Pistons and cylinder bores should be measured at
normal room temperature, 21ÉC (70ÉF).
(1) To correctly select the proper size piston, a cyl-
inder bore gauge, capable of reading in .00019
INCREMENTS is required (Fig. 38). If a bore gauge
is not available, do not use an inside micrometer.The
coating material is applied to the piston after the
final piston machining process. Measuring the out-
side diameter of a coated piston will not provide
accurate results. 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
.00019increments is required.Piston installation into
the cylinder bore require 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) Remove the engine from the vehicle (Refer to 9
- ENGINE - REMOVAL).
(2) Remove cylinder head (Refer to 9 - ENGINE/
CYLINDER HEAD - REMOVAL).
(3) Remove the oil pan and oil pump pick-up tube
(Refer to 9 - ENGINE/LUBRICATION/OIL PAN -
REMOVAL).
(4) 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.
(5) Be sure the connecting rod and connecting rod
cap are identified with the cylinder number. Remove
connecting rod cap. Install connecting rod bolt guide
set on connecting rod bolts.
(6) Pistons and connecting rods must be removed
from top of cylinder block. When removing piston and
connecting rod assemblies, rotate crankshaft center
the connecting rod in the cylinder bore and at BDC.
Be careful not to nick crankshaft journals. DO
NOT try to remove black coating on skirt. This
is the dry film lubricant.
(7) After removal, install bearing cap on the mat-
ing rod.
CLEANING
Clean the piston and connecting rod assembly
using a suitable solvent.
INSPECTION
Check the connecting rod journal for excessive
wear, taper and scoring (Refer to 9 - ENGINE/EN-
GINE BLOCK/CONNECTING ROD BEARINGS -
STANDARD PROCEDURE).
Check the connecting rod for signs of twist or bend-
ing.
Check the piston for taper and elliptical shape
before it is fitted into the cylinder bore (Refer to 9 -
ENGINE/ENGINE BLOCK/PISTON & CONNECT-
ING ROD - STANDARD PROCEDURE).
Check the piston for scoring, or scraping marks in
the piston skirts. Check the ring lands for cracks
and/or deterioration.
INSTALLATION
(1) Check the crankshaft connecting rod journal
for excessive wear, taper and scoring.
(2) Check the cylinder block bore for out-of-round,
taper, scoring and scuffing.
(3) Be sure that compression ring gaps are stag-
gered so that neither is in line with oil ring rail gap.
(4) Before installing the ring compressor, make
sure the oil ring expander ends are butted and the
rail gaps located properly (Fig. 39).
Fig. 38 Bore Gauge
1 - BORE GAUGE
2 - CYLINDER BORE
3 - 2-5/16 in.
DRENGINE 8.0L 9 - 389
PISTON & CONNECTING ROD (Continued)

VIBRATION DAMPER
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Remove the following:
²Radiator fan (Refer to 7 - COOLING/ENGINE/
RADIATOR FAN - REMOVAL)
²Accessory drive belt (Refer to 7 - COOLING/AC-
CESSORY DRIVE/DRIVE BELTS - REMOVAL)
²Radiator (Refer to 7 - COOLING/ENGINE/RA-
DIATOR - REMOVAL)
(3) Remove crankshaft pulley/damper bolt and
washer from end of crankshaft.
(4) Using Special Tool, 1026 3 Jaw Puller and Spe-
cial Tool 8513 Insert, remove pulleyÐdamper from
the crankshaft (Fig. 45).
(5) Inspect crankshaft oil seal. If damaged or
worn, replace the front oil seal (Refer to 9 - ENGINE/
ENGINE BLOCK/CRANKSHAFT OIL SEAL -
FRONT - REMOVAL).
INSTALLATION
(1) Position the crankshaft pulley/damper onto the
crankshaft.
(2) Use Special Tool, C-3688 Crankshaft Pulley/
Damper Installer to press the pulleyÐdamper onto
the crankshaft. Install crankshaft bolt and washer
and tighten to 312 N´m (230 ft. lbs.) torque (Fig. 46).
(3) Install the following:
²Radiator (Refer to 7 - COOLING/ENGINE/RA-
DIATOR - INSTALLATION)²Accessory drive belt (Refer to 7 - COOLING/AC-
CESSORY DRIVE/DRIVE BELTS - INSTALLATION)
²Radiator fan (Refer to 7 - COOLING/ENGINE/
RADIATOR FAN - INSTALLATION)
(4) Connect the negative cable to the battery.
FRONT MOUNT
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Position fan to assure clearance for radiator top
tank and hose.
CAUTION: DO NOT lift the engine by the intake
manifold.
(3) Install engine support/lifting fixture.
(4) Raise vehicle on hoist.
(5) Lift the engine SLIGHTLY and remove the
thru-bolt and nut.
(6) Remove engine support bracket/cushion bolts.
Remove the support bracket/cushion and heat
shields.
INSTALLATION
(1) With engine raised SLIGHTLY, position the
engine support bracket/cushion and heat shields to
the block. Install new bolts and tighten to 81 N´m (60
ft. lbs.) torque.
(2) Install the thru-bolt and 2 piece rubber engine
rubber restrictors onto the engine support bracket/
cushion.
Fig. 45 Crankshaft PulleyÐDamper Removal
1-3JAWPULLER
Fig. 46 Installing Crankshaft PulleyÐDamper
1 - SPECIAL TOOL C-3688
9 - 392 ENGINE 8.0LDR

(3) Lower engine with support/lifting fixture while
guiding the engine bracket/cushion and thru-bolt into
support cushion brackets.
(4) Install thru-bolt nuts and tighten the nuts to
68 N´m (50 ft. lbs.) torque.
(5) Lower the vehicle.
(6) Remove lifting fixture.
REAR MOUNT
REMOVAL
(1) Raise the vehicle on a hoist.
(2) Position a transmission jack in place.
(3) Remove support cushion stud nuts (Fig. 47).
(4) Raise rear of transmission and engine
SLIGHTLY.
(5) Remove the bolts holding the support cushion
to the transmission support bracket. Remove the sup-
port cushion.
(6) If necessary, remove the bolts holding the
transmission support bracket to the transmission.
INSTALLATION
(1) If removed, position the transmission support
bracket to the transmission. Install new attaching
bolts and tighten to 102 N´m (75 ft. lbs.) torque.(2) Position support cushion to transmission sup-
port bracket. Install stud nuts and tighten to 47 N´m
(35 ft. lbs.) torque.
(3) Using the transmission jack, lower the trans-
mission and support cushion onto the crossmember
(Fig. 110).
(4) Install the support cushion bolts and tighten to
47 N´m (35 ft. lbs.) torque.
(5) Remove the transmission jack.
(6) Lower the vehicle.
LUBRICATION
DESCRIPTION
A pressure feed type (gerotor) oil pump is located
in the engine front cover. The pump uses a pick-up
tube and screen assembly to gather engine oil from
the oil pan (Fig. 48).
OPERATION
The pump draws oil through the screen and inlet
tube from the sump at the rear of the oil pan. The oil
is driven between the inner and outer gears of the oil
pump, then forced through the outlet in the engine
front cover. An oil gallery in the front cover channels
the oil to the inlet side of the full flow oil filter. After
passing through the filter element, the oil passes
Fig. 47 Engine Rear Support Cushion Asse
DRENGINE 8.0L 9 - 393
FRONT MOUNT (Continued)

from the center outlet of the filter through an oil gal-
lery that channels the oil up to the tappet galleries,
which extends the entire length of block.
Galleries extend downward from the main oil gal-
lery to the upper shell of each main bearing. The
crankshaft is drilled internally to pass oil from the
main bearing journals to the connecting rod journals.
Each connecting rod bearing has half a hole in it, oil
passes through the hole when the rods rotate and the
hole lines up, oil is then thrown off as the rod
rotates. This oil throwoff lubricates the camshaft
lobes, cylinder walls, and piston pins.
The hydraulic valve tappets receive oil directly
from the main oil gallery. The camshaft bearings
receive oil from the main bearing galleries. The front
camshaft bearing journal passes oil through the cam-
shaft sprocket to the timing chain. Oil drains back to
the oil pan under the No. 1 main bearing cap.
The oil supply for the rocker arms and bridged
pivot assemblies is provided by the hydraulic valve
tappets, which pass oil through hollow push rods to a
hole in the corresponding rocker arm. Oil from the
rocker arm lubricates the valve train components.
The oil then passes down through the push rod guide
holes and the oil drain-back passages in the cylinder
head, past the valve tappet area, and then returns to
the oil pan (Fig. 49).
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTINGÐENGINE OIL
LEAKS
Begin with a through 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
be sure the dye is thoroughly mixed as indicated
with a bright yellow color under a black light source.
(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 24km (15 miles), and
repeat previous step.
(5) If the oil leak source is not positively identified
at this time, proceed with the air leak detection test
method as follows:
(6) Disconnect the breather cap to air cleaner hose
at the breather cap end. Cap or plug breather cap
nipple.
(7) Remove the PCV valve from the cylinder head
cover. Cap or plug the PCV valve grommet.
(8) 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.
(9) 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.
(10) If the leakage occurs at the rear oil seal area,
refer to the section, Inspection for Rear Seal Area
Leak.
(11) If no leaks are detected, turn off the air sup-
ply and remove the air hose and all plugs and caps.
Install the PCV valve and breather cap hose. Proceed
to next step.
(12) 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.
Fig. 48 Pressure Feed Type (Gerotor) Oil PumpÐ
Typical
1 - OUTER ROTOR
2 - INNER ROTOR
3 - OIL PUMP COVER
4 - TIMING CHAIN COVER
9 - 394 ENGINE 8.0LDR
LUBRICATION (Continued)

OIL FILTER
REMOVAL
All engines are equipped with a high quality full-
flow, disposable type oil filter. DaimlerChrysler Cor-
poration recommends a Mopartor equivalent oil
filter be used.
(1) Position a drain pan under the oil filter.
(2) Using a suitable oil filter wrench loosen filter.
(3) Rotate the oil filter counterclockwise to remove
it from the cylinder block oil filter boss (Fig. 51).
(4) When filter separates from adapter nipple, tip
gasket end upward to minimize oil spill. Remove fil-
ter from vehicle.
(5) With a wiping cloth, clean the gasket sealing
surface (Fig. 52) of oil and grime.
(6) Install new filter (Refer to 9 - ENGINE/LUBRI-
CATION/OIL FILTER - INSTALLATION).
INSTALLATION
(1) Lightly lubricate oil filter gasket with engine
oil or chassis grease.
(2) Thread filter onto adapter nipple. When gasket
makes contact with sealing surface, (Fig. 52) hand
tighten filter one full turn, do not over tighten.
(3) Add oil (Refer to 9 - ENGINE/LUBRICATION/
OIL - STANDARD PROCEDURE).
OIL PAN
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Raise vehicle.
(3) Drain engine oil.
(4) Remove left engine to transmission strut.
(5) Remove oil pan mounting bolts, pan and one-
piece gasket. The engine may have to be raised
slightly on 2WD vehicles.(6) Remove the oil pick-up tube assembly (Fig. 53).
Discard the gasket.
CLEANING
Clean the block and pan gasket surfaces.
If present, trim excess sealant from inside the
engine.
Clean oil pan in solvent and wipe dry with a clean
cloth.
Clean oil screen and pipe thoroughly in clean sol-
vent. Inspect condition of screen.
INSPECTION
Inspect oil drain plug and plug hole for stripped or
damaged threads. Repair as necessary.
Inspect oil pan mounting flange for bends or distor-
tion. Straighten flange, if necessary.
Fig. 51 Oil Filter RemovalÐTypical
1 - ENGINE OIL FILTER
2 - OIL FILTER WRENCH
Fig. 52 Oil Filter Sealing SurfaceÐTypical
1 - SEALING SURFACE
2 - RUBBER GASKET
3 - OIL FILTER
Fig. 53 Oil Pick-Up Tube
1 - PICKÐUP TUBE
2 - SEALANT AT SPLIT-LINES
3 - SEALANT AT SPLIT-LINE
DRENGINE 8.0L 9 - 397

INSTALLATION
(1) Fabricate 4 alignment dowels from 5/16x11/2
inch bolts. Cut the head off the bolts and cut a slot
into the top of the dowel. This will allow easier
installation and removal with a screwdriver (Fig. 54).
(2) Install the dowels in the cylinder block at the
four corners.
(3) Apply small amount of MopartSilicone Rubber
Adhesive Sealant, or equivalent at the split lines.
The split lines are between the cylinder block, the
timing chain cover and the rear crankshaft seal
assembly (Fig. 53).After the sealant is applied
you have 3 minutes to install the gasket and oil
pan.
(4) Slide the one-piece gasket over the dowels and
onto the block.
(5) Position the oil pan over the dowels and onto
the gasket. The engine may have to be slightly raised
on 2WD vehicles.
(6) Install the oil pan bolts (Fig. 55). Tighten the
bolts to as shown in Oil Pan Bolts Torque Chart.(7) Remove the dowels. Install the remaining 5/16
inch oil pan bolts. Torque these bolts as shown in Oil
Pan Bolts Torque Chart.
(8) Install the drain plug. Tighten drain plug to 34
N´m (25 ft. lbs.) torque.
(9) Install the engine to transmission strut.
(10) Lower vehicle.
(11) Connect the negative cable to the battery.
(12) Fill crankcase with oil to proper level.
(13) Start engine and check for leaks.
OIL PUMP
REMOVAL
(1) Remove the timing chain cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - REMOVAL).
(2) Remove the relief valve plug, gasket, spring
and valve (Fig. 56). Discard the gasket.
(3) Remove mounting screws and oil pump cover
(Fig. 57).
(4) Remove oil pump inner and outer rotors (Fig.
57).
(5) Inspect oil pump for wear (Refer to 9 -
ENGINE/LUBRICATION/OIL PUMP - INSPEC-
TION).
CLEANING
Wash all parts in a suitable solvent and inspect
carefully for damage or wear.
Fig. 54 Fabrication of Alignment Dowels
1 - 5/16º X 11¤2º BOLT
2 - DOWEL
3 - SLOT
Fig. 55 Oil Pan Bolt Location
1 - OIL PAN
2 - OIL FILTER
3 - STUD BOLTS
4 - DRAIN PLUG
Fig. 56 Oil Pressure Relief Valve
1 - TIMING CHAIN COVER
2 - OIL PUMP RELIEF VALVE
3 - SPRING
4 - GASKET
5 - PLUG
9 - 398 ENGINE 8.0LDR
OIL PAN (Continued)