
(5) Using Special Tool C-3688 Crankshaft Pulley/
Damper Installer Install pulley/vibration damper
(Fig. 75)
(6) Prime oil pump by squirting oil in the oil filter
mounting hole and filling the J-trap of the front tim-
ing cover. When oil is running out, install oil filter
that has been filled with oil.(7) Install water pump and housing assembly
using new o-ring (Refer to 7 - COOLING/ENGINE/
WATER PUMP - INSTALLATION).
(8) Install generator, air pump, and bracket assem-
bly.
(9) Install A/C compressor (Refer to 24 - HEATING
& AIR CONDITIONING/PLUMBING/A/C COM-
PRESSOR - INSTALLATION).
(10) (10) Install the radiator fan (Refer to 7 -
COOLING/ENGINE/RADIATOR FAN - INSTALLA-
TION).
(11) Position the fan shroud and install the bolts.
Tighten the bolts to 11 N´m (95 in. lbs.) torque.
(12) Install the serpentine belt (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - INSTAL-
LATION).
(13) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(14) Connect the negative cable to the battery.
(15) Road test vehicle and check for leaks.
TIMING BELT/CHAIN AND
SPROCKETS
REMOVAL
(1) Remove timing chain cover and gasket using
extreme caution to avoid damaging oil pan gasket
(Refer to 9 - ENGINE/VALVE TIMING/TIMING
BELT / CHAIN COVER(S) - REMOVAL).
(2) Aline camshaft and crankshaft centerline.
Remove camshaft sprocket attaching bolt and remove
timing chain and camshaft sprockets.
(3) Use puller 6444 and jaws 6820 to remove
crankshaft sprocket (Fig. 76).
INSPECTIONÐMEASURING TIMING CHAIN
STRETCH
(1) Place a scale next to the timing chain so that
any movement of the chain may be measured.
(2) Place a torque wrench and socket over cam-
shaft sprocket attaching bolt. Apply torque in the
direction of crankshaft rotation to take up slack; 41
N´m (30 ft. lbs.) torque with cylinder head installed
or 20 N´m (15 ft. lbs.) torque with cylinder head
removed. With a torque applied to the camshaft
sprocket bolt, crankshaft should not be permitted to
move. It may be necessary to block the crankshaft to
prevent rotation.
(3) Hold a scale with dimensional reading even
with the edge of a chain link. With cylinder heads
installed, apply 14 N´m (30 ft. lbs.) torque in the
reverse direction. With the cylinder heads removed,
apply 20 N´m (15 ft. lbs.) torque in the reverse direc-
tion. Note the amount of chain movement (Fig. 77).
Fig. 74 PulleyÐDamper Removal
1-3JAWPULLER
Fig. 75 Installing Crankshaft
1 - SPECIAL TOOL C-3688
DRENGINE 8.0L 9 - 405
TIMING BELT / CHAIN COVER(S) (Continued)

(4) Install a new timing chain, if its movement
exceeds 3.175 mm (1/8 inch).
INSTALLATION
(1) Line up key in crankshaft with keyway in
sprocket, press on crankshaft timing sprocket, use
tools C-3688, C-3718 and MB-990799, seat sprocket
against crankshaft shoulder (Fig. 78).
(2) Turn crankshaft to line up the timing mark
with the crankshaft and camshaft centerline.
(3) Put chain on camshaft sprocket.
(4) Align timing marks and install chain and cam-
shaft sprocket onto crankshaft sprocket. Check to see
that timing marks are on the centerline of the crank-
shaft and camshaft centerline (Fig. 79).(5) Install the camshaft bolt. Tighten the bolt to 61
N´m (45 ft. lbs.) torque.
(6) Check camshaft end play. The end play should
be 0.051-0.152 mm (0.002-0.006 inch) with a new
thrust plate and up to 0.254 mm (0.010 inch) with a
used thrust plate. If not within these limits install a
new thrust plate.
(7) Install timing chain cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION).
Fig. 76 Crankshaft Sprocket Removal.
1 - SPECIAL TOOL 6444
2 - SPECIAL TOOL 6820
Fig. 77 Measuring Timing Chain Stretch
1 - TORQUE WRENCH
2 - 3.175 MM
(0.125 IN.)
Fig. 78 Crankshaft Sprocket Installation
1 - SPECIAL TOOL C-3688
2 - SPECIAL TOOL C-3718
3 - SPECIAL TOOL MD990799
Fig. 79 Alignment of Timing Marks
1 - CAMSHAFT SPROCKET
2 - CRANKSHAFT SPROCKET
3 - TIMING MARKS
9 - 406 ENGINE 8.0LDR
TIMING BELT/CHAIN AND SPROCKETS (Continued)

(3)Pre-lube the turbocharger.Pour 50 to 60 cc
(2 to 3 oz.) clean engine oil in the oil supply line fit-
ting. Carefully rotate the turbocharger impeller by
hand to distribute the oil thoroughly.
(4) Install and tighten the oil supply line to 24
N´m (18 ft. lbs.) torque.
(5) Position the charge air cooler inlet pipe to the
turbocharger. With the clamp in position, tighten the
clamp nut to 11 N´m (95 in. lbs.) torque.
(6) Position the air inlet hose to the turbocharger
(Fig. 18). Tighten the clamp to 11 N´m (95 in. lbs.)
torque.
(7) Raise vehicle on hoist.
(8) Connect the exhaust pipe to the turbocharger
and tighten the bolts to 34 N´m (25 ft. lbs.) torque.
(9) Lower the vehicle.
(10) Connect the battery negative cables.
(11) Start the engine to check for leaks.
CHARGE AIR COOLER AND
PLUMBING
DESCRIPTION
The charge air system (Fig. 23) consists of the
charge air cooler piping, charge air cooler and intake
air grid heater.
The charge air cooler is a heat exchanger that uses
air flow from vehicle motion to dissipate heat from
the intake air. As the turbocharger increases air
pressure, the air temperature increases. Lowering
the intake air temperature increases engine effi-
ciency and power.
OPERATION
Intake air is drawn through the air cleaner and
into the turbocharger compressor housing. Pressur-ized air from the turbocharger then flows forward
through the charge air cooler located in front of the
radiator. From the charge air cooler the air flows
back into the intake manifold.
DIAGNOSIS AND TESTING - CHARGE AIR
COOLER SYSTEM - LEAKS
Low turbocharger boost pressure and low engine
performance can be caused by leaks in the charge air
cooler or it's plumbing. Fuel staining on the exhaust
manifold can also be an indication that there are
leaks in the air system.The following procedure out-
lines how to check for leaks in the charge air cooler
system.
(1) Loosen clamp and remove air inlet hose from
turbocharger.
(2)
Insert Special Tool 9022 Adapter into the turbo-
charger inlet. Tighten tool clamp to 8 N´m (72 in. lbs.).
CAUTION: Do not apply more than 138 kPa (20 psi)
air pressure to the charge air cooler system, sever
damage to the charge air cooler system may occur.
(3) Connect a regulated air supply to air fitting on
Special Tool 9022 Adapter. Set air pressure to a Max-
imum of 138 kPa (20 psi).
(4) Using soapy water check the rubber sleeves,
charge air cooler and intake manifold for leaks.
REMOVAL
WARNING: IF THE ENGINE WAS JUST TURNED
OFF, THE AIR INTAKE SYSTEM TUBES MAY BE
HOT.
Fig. 22 Measure Turbocharger Bearing Radial
Clearance
1 - FEELER GAUGE
Fig. 23 Intake Air Circulation
1 - CHARGE AIR COOLER
2 - AIRFILTER
3 - TURBOCHARGER
DREXHAUST SYSTEM 11 - 15
TURBOCHARGER (Continued)

(1) Disconnect the battery negative cables.
(2) Discharge the A/C system (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - STAN-
DARD PROCEDURE) and remove the A/C condenser
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING/A/C CONDENSER - REMOVAL) (if A/C
equipped).
(3) Remove the transmission auxiliary cooler
(Refer to 7 - COOLING/TRANSMISSION/TRANS
COOLER - REMOVAL).
(4) Remove the boost tubes from the charge air
cooler (Fig. 24).
(5) Remove the charge air cooler bolts. Pivot the
charge air cooler forward and up to remove.
CLEANING
CAUTION: Do not use caustic cleaners to clean the
charge air cooler. Damage to the charge air cooler
will result.
NOTE: If internal debris cannot be removed from
the cooler, the charge air cooler MUST be replaced.(1) If the engine experiences a turbocharger failure
or any other situation where oil or debris get into the
charge air cooler, the charge air cooler must be
cleaned internally.
(2) Position the charge air cooler so the inlet and
outlet tubes are vertical.
(3) Flush the cooler internally with solvent in the
direction opposite of normal air flow.
(4)
Shake the cooler and lightly tap on the end
tanks with a rubber mallet to dislodge trapped debris.
(5) Continue flushing until all debris or oil are
removed.
(6) Rinse the cooler with hot soapy water to
remove any remaining solvent.
(7) Rinse thoroughly with clean water and blow
dry with compressed air.
INSPECTION
Visually inspect the charge air cooler for cracks,
holes, or damage. Inspect the tubes, fins, and welds
for tears, breaks, or other damage. Replace the
charge air cooler if damage is found.
Pressure test the charge air cooler, using Charge
Air Cooler Tester Kit #3824556. This kit is available
through CumminstService Products. Instructions
are provided with the kit.
INSTALLATION
(1) Position the charge air cooler. Install the bolts
and tighten to 2 N´m (17 in. lbs.) torque.
(2) Install the air intake system tubes to the
charge air cooler. With the clamps in position, tighten
the clamps to 11 N´m (95 in. lbs.) torque.
(3) Install the transmission auxiliary cooler (if
equipped) (Refer to 7 - COOLING/TRANSMISSION/
TRANS COOLER - INSTALLATION).
(4)
Install the A/C condenser (if A/C equipped) (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMB-
ING/A/C CONDENSER - INSTALLATION). Recharge
A/C system (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE).
(5) Connect the battery negative cables.
(6) Start engine and check for boost system leaks.
Fig. 24 Air Intake System Tubes
1 - BOLT
2 - CHARGE AIR COOLER
3 - CLAMP
4 - BOOST TUBE
11 - 16 EXHAUST SYSTEMDR
CHARGE AIR COOLER AND PLUMBING (Continued)

STANDARD PROCEDURE - HYDROFORM
FENDER RAIL REPAIR
SAFETY PRECAUTIONS AND WARNINGS
WARNING: USE EYE PROTECTION WHEN GRIND-
ING OR WELDING METAL, SERIOUS EYE INJURY
CAN RESULT.
²BEFORE PROCEEDING WITH FRAME REPAIR
INVOLVING GRINDING OR WELDING, VERIFY THAT
VEHICLE FUEL SYSTEM IS NOT LEAKING OR IN
CONTACT WITH REPAIR AREA, PERSONAL INJURY
CAN RESULT.
²DO NOT ALLOW OPEN FLAME OR HEAT AND
METAL SPATTER FROM ARC WELDING, TO CON-
TACT PLASTIC BODY PANELS. FIRE OR EXPLO-
SION CAN RESULT.
²WHEN WELDED FRAME COMPONENTS ARE
REPLACED, ENSURE COMPLETE PENETRATION
WELD IS ACHIEVED DURING INSTALLATION. IF
NOT, DANGEROUS OPERATING CONDITIONS CAN
RESULT.
²STAND CLEAR OF CABLES OR CHAINS ON
PULLING EQUIPMENT DURING FRAME STRAIGHT-
ENING OPERATIONS, PERSONAL INJURY CAN
RESULT.
²DO NOT VENTURE UNDER A HOISTED VEHI-
CLE THAT IS NOT SUPPORTED ON SAFETY
STANDS, PERSONAL INJURY CAN RESULT.
CAUTION: Do not reuse damaged fasteners, quality
of repair would be suspect. Failure to use only pro-
duction fasteners or fasteners of equivalent hard-
ness can result in loosening or failure. Do not drill
holes in top or bottom frame rail flanges, frame rail
failure can result. When using heat to straighten
frame components do not exceed 566ÉC (1050ÉF),
metal fatigue can result.
CAUTION: This repair procedure assumes damage
to the right or left hydroform fender rail (Fig. 19).
Prior to any repairs, the vehicle must be mounted
on the appropriate frame repair equipment (ªframe
rackº), checked with three dimensional measuring
equipment, and necessary pull corrections made. If
damage exists in the hydroform fender rail, or cab
beyond the area covered by this service procedure
after dimensional corrections are made, the hydro-
form must be replaced in its entirety. Refer to 23 -
BODY/BODY STRUCTURE/WELD LOCATIONS -
SPECIFICATIONS, when replacing the entire hydro-
form.(1) Disconnect and isolate the battery negative
cable.
(2) Remove the front wheelhouse splash shield.
(Refer to 23 - BODY/EXTERIOR/FRONT WHEEL-
HOUSE SPLASH SHIELD - REMOVAL)
(3) Remove the fender. (Refer to 23 - BODY/EXTE-
RIOR/FRONT FENDER - REMOVAL)
(4) Remove the A/C condenser, if required. (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMB-
ING/A/C CONDENSER - REMOVAL)
(5) Remove the A/C lines, if required. Refer to the
Heating and Air Conditioning section of the manual
for recommended procedures.
(6) Remove the radiator assembly. (Refer to 7 -
COOLING/ENGINE/RADIATOR - REMOVAL)
(7) Remove the air cleaner and support bracket, if
required. (Refer to 9 - ENGINE/AIR INTAKE SYS-
TEM/AIR CLEANER ELEMENT - REMOVAL)
(8) Remove the integrated power module. (Refer to
8 - ELECTRICAL/POWER DISTRIBUTION/INTE-
GRATED POWER MODULE - REMOVAL)
(9) Remove the bolts and position aside the wire
harness and grounds, if required.
(10) Remove the upper radiator crossmember.
(Refer to 23 - BODY/EXTERIOR/UPPER RADIATOR
CROSSMEMBER - REMOVAL)
(11) Remove the headlamp unit. (Refer to 8 -
ELECTRICAL/LAMPS/LIGHTING - EXTERIOR/
HEADLAMP UNIT - REMOVAL)
(12) Remove the front cab mount to the Front End
Sheet Metal bracket (FESM) bolt.
(13) Remove the bolts attaching the lower radiator
crossmember to the hydroform fender rail. (Fig. 19)
CAUTION: Do not use any flame or plasma cutting
equipment to cut the frame in this procedure. The
inaccurate and high temperatures achieved during
flame or plasma cutting will change the metal char-
acteristics and may weaken the frame and/or repair
location.
(14) Using a reciprocating saw or equivalent, cut
the fender rail and shotgun at a straight and square
section of the hydroform and remove.
(15) Smooth and square the cut edges.
(16) Using the damaged structure as a reference
cut the service part at the same location as the first
cut. Smooth and square the cut edges.
NOTE: The repair structure should butt up to the
remaining structure and provide the same overall
vehicle geometry.
13 - 12 FRAMES & BUMPERSDR
FRAME (Continued)

OPERATION
Fuel is returned through the fuel pump module
and back into the fuel tank through the fuel filter/
fuel pressure regulator. A separate fuel return line
from the engine to the tank is not used.
The fuel tank assembly consists of: the fuel tank,
fuel pump module assembly, fuel pump module lock-
nut/gasket, and fuel tank check valve (refer to Fuel
Tank Check Valve for information).
A fuel filler/vent tube assembly using a pressure/
vacuum, 1/4 turn fuel filler cap is used. The fuel
filler tube contains a flap door located below the fuel
fill cap.
Also to be considered part of the fuel system is the
evaporation control system. This is designed to
reduce the emission of fuel vapors into the atmo-sphere. The description and function of the Evapora-
tive Control System is found in Emission Control
Systems.
Both fuel filters (at bottom of fuel pump module
and within fuel pressure regulator) are designed for
extended service. They do not require normal sched-
uled maintenance. Filters should only be replaced if
a diagnostic procedure indicates to do so.
STANDARD PROCEDURE - FUEL SYSTEM
PRESSURE RELEASE
Use following procedure if the fuel injector
rail is, or is not equipped with a fuel pressure
test port.
(1) Remove fuel fill cap.
Fig. 1 FUEL DELIVERY COMPONENTS
1 - FUEL TANK 8 - LDP FRESH AIR FILTER
2 - CHECK VALVE 9 - LEAK DETECTION PUMP
3 - LIQUID EXPANSION CHAMBER 10 - EVAP CANISTERS (2)
4 - FUEL FILTER / FUEL PRESSURE REGULATOR 11 - FUEL TANK STRAPS (2)
5 - QUICK-CONNECT FITTING AND FUEL LINE (TO ENGINE) 12 - CHECK VALVE
6 - EVAP LINE CONNECTION 13 - FUEL PUMP MODULE LOCK RING
7 - LEAK DETECTION PUMP FRESH AIR LINE 14 - FUEL PUMP MODULE
14 - 2 FUEL DELIVERY - GASDR
FUEL DELIVERY - GAS (Continued)

FUEL FILTER/PRESSURE
REGULATOR
DESCRIPTION
A combination fuel filter and fuel pressure regula-
tor (Fig. 2) is used on all engines. It is located on the
top of the fuel pump module. A separate frame
mounted fuel filter is not used with any engine.
Both fuel filters (at bottom of fuel pump module
and within fuel pressure regulator) are designed for
extended service. They do not require normal sched-
uled maintenance. Filters should only be replaced if
a diagnostic procedure indicates to do so.
OPERATION
Fuel Pressure Regulator Operation:The pres-
sure regulator is a mechanical device that is not con-
trolled by engine vacuum or the Powertrain Control
Module (PCM).
The regulator is calibrated to maintain fuel system
operating pressure of approximately 339 kPa 34
kPa (49.2 psi 5 psi) at the fuel injectors. It contains
a diaphragm, calibrated springs and a fuel return
valve. The internal fuel filter (Fig. 2) is also part of
the assembly.
Fuel is supplied to the filter/regulator by the elec-
tric fuel pump through an opening tube at the bot-
tom of filter/regulator (Fig. 2).
The regulator acts as a check valve to maintain
some fuel pressure when the engine is not operating.
This will help to start the engine. A second check
valve is located at the outlet end of the electric fuel
ADAPTERS, FUEL PRESSURE TEST, 8.0L - #6539
AND/OR #6631
SPANNER WRENCH - #6856
FITTING, AIR METERING - #6714
O2S (OXYGEN SENSOR) REMOVER/INSTALLER -
#C-4907
Fig. 2 SIDE VIEW - FILTER/REGULATOR
1 - INTERNAL FUEL FILTER
2 - FUEL FLOW TO FUEL INJECTORS
3 - FUEL FILTER/FUEL PRESSURE REGULATOR
4 - EXCESS FUEL BACK TO TANK
5 - FUEL INLET
6 - RUBBER GROMMET
7 - TOP OF PUMP MODULE
14 - 6 FUEL DELIVERY - GASDR
FUEL DELIVERY - GAS (Continued)

(Fig. 12) or (Fig. 13). Type-1 is tethered to fuel line
and type-2 is not. A special tool will be necessary to
disconnect fuel line after latch clip is removed. The
latch clip may be used on certain fuel line/fuel rail
connection, or to join fuel lines together.
(a) Type 1: Pry up on latch clip with a screw-
driver (Fig. 12).
(b) Type 2: Separate and unlatch 2 small arms
on end of clip (Fig. 13) and swing away from fuel
line.(c) Slide latch clip toward fuel rail while lifting
with screwdriver.
(d) Insert special fuel line removal tool (Snap-On
number FIH 9055-1 or equivalent) into fuel line
(Fig. 14). Use tool to release locking fingers in end
of line.
(e) With special tool still inserted, pull fuel line
from fuel rail.
(f)
After disconnection, locking fingers will remain
within quick-connect fitting at end of fuel line.
(10) Disconnect quick-connect fitting from fuel sys-
tem component being serviced.
CONNECTING
(1) Inspect quick-connect fitting body and fuel sys-
tem component for damage. Replace as necessary.
(2) Prior to connecting quick-connect fitting to
component being serviced, check condition of fitting
and component. Clean parts with a lint-free cloth.
Lubricate with clean engine oil.
(3) Insert quick-connect fitting into fuel tube or
fuel system component until built-on stop on fuel
tube or component rests against back of fitting.
(4) Continue pushing until a click is felt.
(5) Single-tab type fitting: Push new tab down
until it locks into place in quick-connect fitting.
(6) Verify a locked condition by firmly pulling on
fuel tube and fitting (15-30 lbs.).
(7) Latch Clip Equipped: Install latch clip (snaps
into position).If latch clip will not fit, this indi-
cates fuel line is not properly installed to fuel
rail (or other fuel line). Recheck fuel line con-
nection.
(8) Connect negative cable to battery.
(9) Start engine and check for leaks.
Fig. 12 LATCH CLIP-TYPE 1
1 - TETHER STRAP
2 - FUEL LINE
3 - SCREWDRIVER
4 - LATCH CLIP
5 - FUEL RAIL
Fig. 13 LATCH CLIP-TYPE 2
1 - LATCH CLIP
Fig. 14 FUEL LINE DISCONNECTION USING
SPECIAL TOOL
1 - SPECIAL FUEL LINE TOOL
2 - FUEL LINE
3 - FUEL RAIL
DRFUEL DELIVERY - GAS 14 - 11
QUICK CONNECT FITTING (Continued)