DODGE RAM 2003 Service Repair Manual

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)

Fig. 49 Engine Lubrication System
DRENGINE 8.0L 9 - 395
LUBRICATION (Continued)

DIAGNOSIS AND TESTINGÐENGINE OIL
PRESSURE
(1) Remove oil pressure sending unit.
(2) Install Oil Pressure Line and Gauge Tool
C-3292. Start engine and record pressure. (Refer to 9
- ENGINE - SPECIFICATIONS).
OIL
STANDARD PROCEDURE - ENGINE OIL
OIL LEVEL INDICATOR (DIPSTICK)
The engine oil level indicator is located at the right
front of the engine, left of the generator (Fig. 50).
CRANKCASE OIL LEVEL INSPECTION
CAUTION: Do not overfill crankcase with engine oil,
oil foaming and oil pressure loss can result.To ensure proper lubrication of an engine, the
engine oil must be maintained at an acceptable level.
The acceptable levels are indicated between the ADD
and SAFE marks on the engine oil dipstick.
(1) Position vehicle on level surface.
(2) With engine OFF, allow approximately ten min-
utes for oil to settle to bottom of crankcase, remove
engine oil dipstick.
(3) Wipe dipstick clean.
(4)
Install dipstick and verify it is seated in the tube.
(5) Remove dipstick, with handle held above the
tip, take oil level reading.
(6) Add oil only if level is below the ADD mark on
dipstick.
ENGINE OIL CHANGE
Change engine oil at mileage and time intervals
described in the Maintenance Schedule. This infor-
mation can be found in the owner's manual.
TO CHANGE ENGINE OIL
Run engine until achieving normal operating tem-
perature.
(1) Position the vehicle on a level surface and turn
engine off.
(2) Hoist vehicle.
(3) Remove oil fill cap.
(4)
Place a suitable drain pan under crankcase drain.
(5) Remove drain plug from crankcase and allow
oil to drain into pan. Inspect drain plug threads for
stretching or other damage. Replace drain plug and
gasket if damaged.
(6) Install drain plug in crankcase.
(7) Change oil filter (Refer to 9 - ENGINE/LUBRI-
CATION/OIL FILTER - REMOVAL).
(8) Lower vehicle and fill crankcase with specified
type (Refer to LUBRICATION & MAINTENANCE/
FLUID TYPES - DESCRIPTION) and amount of
engine oil (Refer to LUBRICATION & MAINTE-
NANCE - SPECIFICATIONS).
(9) Install oil fill cap.
(10) Start engine and inspect for leaks.
(11) Stop engine and inspect oil level.
1 - OIL TO MAIN OIL GALLERIES
2 - RELIEF VALVE
3 - OIL GALLERY FOR TAPPETS
4 - MAIN OIL GALLERY
5 - TAPPET OIL GALLERY
6 - HOLLOW PUSH ROD
7 - ROCKER ARM
8 - PLUG
9 - GASKET
10 - SPRING
11 - TIMING CHAIN COVER
12 - CAM BEARINGS
13 - HYDRAULIC TAPPET GALLERIES
14 - CAMSHAFT
15 - CRANKSHAFT16 - OIL PASSAGE TO CONNECTING ROD JOURNALS
17 - OIL PICKUP
18 - CONNECTING ROD JOURNALS
19 - CRANKSHAFT BEARINGS
20 - MAIN OIL GALLERY
21 - CRANKSHAFT
22 - OIL PICKUP TUBE
23 - CONNECT ROD JOURNALS
24 - CAMSHAFT BEARINGS
25 - TAPPET OIL GALLERY
26 - OIL FROM PICKUP TUBE
27 - CAMSHAFT
28 - TAPPET
29 - VALVE
30 - OIL PUMP RELIEF VALVE
Fig. 50 Oil Level Indicator Location
1 - CYLINDER HEAD COVER
2 - ENGINE OIL FILL CAP
3 - DIPSTICK
4 - ENGINE OIL FILTER
5 - FILTER BOSS
9 - 396 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)

INSPECTION
Mating surface of the oil pump cover should be
smooth. Replace pump cover if scratched or grooved.
Lay a straightedge across the pump cover surface
(Fig. 58). If a 0.076 mm (0.003 inch) feeler gauge can
be inserted between cover and straightedge, cover
should be replaced.
Measure thickness (Fig. 59) (Fig. 60) and diameter
of rotors. If either rotor thickness measures 14.956mm (0.5876 inch) or less, or if the diameter is 82.45
mm (3.246 inches) or less, replace rotor set.
Slide outer rotor into timing chain cover pump
body. Press rotor to the side with your fingers and
measure clearance between rotor and pump body
(Fig. 61). If clearance is 0.19 mm (0.007 inch) or
more, and outer rotor is within specifications, replace
timing chain cover.
Install inner rotor into timing chain cover pump
body (Fig. 62). Inner rotor should be positioned with
chamfer up or toward engine when cover is installed.
This allows easy installation over crankshaft. If
clearance between inner and outer rotors is 0.150
mm (0.006 inch) or more, replace both rotors.
Place a straightedge across the face of the timing
chain cover pump body, between bolt holes (Fig. 63).
If a feeler gauge of 0.077 mm (0.003 inch) or more
can be inserted between rotors and the straightedge,
and the rotors are within specifications, replace tim-
ing chain cover.
Fig. 57 Oil Pump
1 - OUTER ROTOR
2 - INNER ROTOR
3 - OIL PUMP COVER
4 - TIMING CHAIN COVER
Fig. 58 Checking Oil Pump Cover Flatness
1 - FEELER GAUGE
2 - STRAIGHT EDGE
3 - OIL PUMP COVER
Fig. 59 Measuring Outer Rotor Thickness
Fig. 60 Measuring Inner Rotor Thickness
DRENGINE 8.0L 9 - 399
OIL PUMP (Continued)

Inspect oil pressure relief valve plunger for scoring
and free operation in its bore. Small marks may be
removed with 400-grit wet or dry sandpaper.
The relief valve spring has a free length of approx-
imately 49.5 mm (1.95 inches). The spring should
test between 100 and 109 N (22.5 and 24.5 pounds)
when compressed to 34 mm (1-11/32 inches). Replace
spring that fails to meet these specifications.
If oil pressure was low and pump is within specifi-
cations, inspect for worn engine bearings or other
reasons for oil pressure loss.
INSTALLATION
(1) Lubricate both oil pump rotors using petroleum
jelly or lubriplate and install in the timing chain
cover. Use new parts as required (Fig. 64).(2) Position the oil pump cover onto the timing
chain cover. Tighten cover screws to 14 N´m (125 in.
lbs.) torque.
(3) Make sure that inner ring moves freely after
cover is installed.
(4) Install the timing chain cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION).
(5) Squirt oil into relief valve hole until oil runs
out.
(6) Install the relief valve and spring.
Fig. 61 Measuring Outer Rotor Clearance in Cover
1 - FEELER GAUGE
2 - OUTER ROTOR
Fig. 62 Measuring Inner Rotor Clearance in Cover
1 - FEELER GAUGE
2 - OUTER ROTOR
3 - INNER ROTOR
Fig. 63 Measuring Clearance Over Rotors
1 - FEELER GAUGE
2 - STRAIGHT EDGE
Fig. 64 Priming Oil Pump.
1 - FILL WITH PETROLEUM JELLY OR LUBER PLATE
9 - 400 ENGINE 8.0LDR
OIL PUMP (Continued)

(7) Using a new pressure relief valve gasket,
install the relief valve plug. Tighten the plug to 20
N´m (15 ft. lbs.) torque.
(8) Install oil filter that has been filled with oil.
INTAKE MANIFOLD
DESCRIPTION
The aluminum intake manifold (Fig. 65) has two
plenum chambers an upper and lower which supply
air to five runners each. Passages across the longitu-
dinal center of the manifold feed air from the throttle
body to the plenum chambers.
DIAGNOSIS AND TESTINGÐINTAKE
MANIFOLD LEAKAGE
An intake manifold air leak is characterized by
lower than normal manifold vacuum. Also, one or
more cylinders may not be functioning.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS, OR THE FAN.
DO NOT WEAR LOOSE CLOTHING.
(1) Start the engine.
(2) Spray a small stream of water at the suspected
leak area.(3) If a change in RPMs occur, the area of the sus-
pected leak has been found.
(4) Repair as required.
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Drain the cooling system (Refer to 7 - COOL-
ING - STANDARD PROCEDURE).
(3) Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(4) Remove the generator brace and generator
(Fig. 66).
(5) Remove the A/C compressor brace (Fig. 66).
Remove the compressor and set aside.
(6) Remove the air cleaner cover and filter.
Remove the air cleaner housing (Fig. 67). Discard the
gasket.
(7) Perform the Fuel System Pressure release pro-
cedure (Refer to 14 - FUEL SYSTEM/FUEL DELIV-
ERY - STANDARD PROCEDURE). Disconnect the
fuel lines (Refer to 14 - FUEL SYSTEM/FUEL
DELIVERY/QUICK CONNECT FITTING - STAN-
DARD PROCEDURE).
(8) Disconnect the accelerator linkage and if so
equipped, the speed control and transmission kick-
down cables.
(9) Remove the coil assemblies with the ignition
wires.
(10) Disconnect the vacuum lines.
(11) Disconnect the heater hoses and bypass hose.
(12) Remove the closed crankcase ventilation and
evaporation control systems.
Fig. 65 Upper and Lower Intake ManifoldÐ8.0L
Engine
1 - UPPER INTAKE MANIFOLD
2 - THROTTLE BODY (MPI)
3 - LOWER INTAKE MANIFOLD
Fig. 66 Generator and A/C Compressor Braces
1 - GENERATOR
2 - INTAKE MANIFOLD TO GENERATOR BRACE
3 - A/C COMPRESSOR
4 - INTAKE MANIFOLD TO A/C COMPRESSOR BRACE
DRENGINE 8.0L 9 - 401
OIL PUMP (Continued)