fuel DODGE RAM 2002 Service Repair Manual

original locations (Fig. 53). Tighten bolts to 36 N´m
(27 ft. lbs.) torque.
(4)Verify valve lash adjustment (Refer to 9 -
ENGINE/CYLINDER HEAD/INTAKE/EXHAUST
VALVES & SEATS - STANDARD PROCEDURE).
(5) Install cylinder head cover and reusable gasket
(Fig. 52) (Refer to 9 - ENGINE/CYLINDER HEAD/
CYLINDER HEAD COVER(S) - INSTALLATION).
(6) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(7) Connect battery negative cables.
ROCKER ARM / ADJUSTER
ASSY
DESCRIPTION
The 24±valve overhead system incorporates rocker
arms that are designed to allow fuel injector service
without removing the rocker arms and pedestals. The
unique intake and exhaust rocker arms have their
own rocker shafts and are lubricated by passages
intersecting the cylinder block main oil rifle. Cross-
heads are used (Fig. 58), which allow each rocker
arm to operate two valves.
The solid push rods are hardened at the rocker
arm and tappet contact areas for superior strength
and durability.
REMOVAL
(1) Disconnect the battery negative cables.
(2) Remove cylinder head cover (Fig. 59) (Refer to
9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(3) Remove the rocker arm/pedestal fasteners (Fig.
60) and remove rocker arm and pedestal from cylin-
der head. Mark the arms and pedestals so they can
be installed in their original position.
CAUTION: When removing the rocker arms, the
sockets (Fig. 61) may come loose and fall into the
engine. Make sure they stay with the arm upon
removal/installation.
Fig. 56 Spring Compressor Mounting BaseÐPart of
Tool 8319±A
1 - COMPRESSOR MOUNTING BASE
Fig. 57 Compressing Valve Springs with Tool
8319±A
1 - SPECIAL TOOL 8319
Fig. 58 Overhead System Components
1 - EXHAUST ROCKER ARM
2 - INTAKE ROCKER ARM
3 - ROCKER SHAFT
4 - SOCKET
5 - ADJUSTING SCREW LOCK NUT
6 - PUSH ROD
7 - PEDESTAL
8 - CROSSHEAD
BR/BEENGINE 5.9L DIESEL 9 - 145
INTAKE/EXHAUST VALVES & SEATS (Continued)

(3) Always check the condition of the used oil. This
can give you an indication of engine problems that
might exist.
²Thin, black oil indicates fuel dilution.
²Milky discoloration indicates coolant dilution.
(4) Clean the area around the oil filter head.
Remove the filter (Refer to 9 - ENGINE/LUBRICA-
TION/OIL FILTER - REMOVAL).
(5) Install new oil filter (Refer to 9 - ENGINE/LU-
BRICATION/OIL FILTER - INSTALLATION).
(6) Clean the drain plug and the sealing surface of
the pan. Check the condition of the threads and seal-
ing surface on the oil pan and drain plug.
(7) Install the drain plug. Tighten the plug to 50
N´m (37 ft. lbs.) torque.
(8) Use only High-Quality Multi-Viscosity lubricat-
ing oil in the Cummins Turbo Diesel engine. Choose
the correct oil for the operating conditions (Refer to
LUBRICATION & MAINTENANCE/FLUID TYPES -
DESCRIPTION).
(9) Fill the engine with the correct grade of new oil
(Refer to LUBRICATION & MAINTENANCE/FLUID
CAPACITIES - SPECIFICATIONS).
(10) Start the engine and operate it at idle for sev-
eral minutes. Check for leaks at the filter and drain
plug.
(11) Stop engine. Wait several minutes to allow the
oil to drain back to the pan and check the level
again.
USED ENGINE OIL DISPOSAL Care should be
exercised when disposing of used engine oil after
it has been drained from a vehicle's engine.
OIL COOLER & LINES
CLEANING AND INSPECTION
Clean the sealing surfaces.
Apply 483 kPa (70 psi) air pressure to the element
to check for leaks. If the element leaks, replace the
element.
OIL FILTER
REMOVAL
(1) Clean the area around the oil filter head.
Remove the filter using a 90-95 mm filter wrench.
(2) Clean the gasket surface of the filter head. The
filter canister O-Ring seal can stick on the filter
head. Make sure it is removed.
INSTALLATION
(1) Fill the oil filter element with clean oil before
installation. Use the same type oil that will be used
in the engine.
(2) Apply a light film of lubricating oil to the seal-
ing surface before installing the filter.
CAUTION: Mechanical over-tightening may distort
the threads or damage the filter element seal.
(3) Install the filter until it contacts the sealing
surface of the oil filter adapter. Tighten filter an
additional ó turn.
OIL PAN
REMOVAL
(1) Disconnect the battery negative cables.
(2) Raise vehicle on hoist.
(3) Remove transmission and transfer case (if
equipped).
(4) Remove flywheel.
(5) Disconnect starter cables from starter motor.
(6) Remove starter motor (Refer to 8 - ELECTRI-
CAL/STARTING/STARTER MOTOR - REMOVAL)
and transmission adapter plate assembly.
WARNING: HOT OIL CAN CAUSE PERSONAL
INJURY.
(7) Drain the engine oil (Refer to 9 - ENGINE/LU-
BRICATION/OIL - STANDARD PROCEDURE).
(8) Install the oil pan drain plug with a new seal-
ing washer and tighten to 60 N´m (44 ft. lbs.) torque.
(9) Remove oil pan bolts, break the pan to block
seal, and lower pan slightly and remove oil suction
tube fasteners.
(10) Remove oil pan and suction tube (Fig. 151).
CLEANING
Remove all gasket material from the oil pan and
cylinder block sealing surfaces. Extra effort may be
required around T-joint areas. Clean oil pan and
flush suction tube with a suitable solvent.
INSPECTION
Inspect the oil pan, suction tube, and tube braces
for cracks and damage. Replace any defective compo-
nent. Inspect the oil drain plug and drain hole
threads. Inspect the oil pan sealing surface for
straightness. Repair any minor imperfections with a
ball-peen hammer. Do not attempt to repair an oil
pan by welding.
BR/BEENGINE 5.9L DIESEL 9 - 179
OIL (Continued)

(7) Apply a bead of MopartSilicone Rubber Adhe-
sive Sealant or equivalent to the gear housing cover
sealing surface.
(8) Install the gear housing cover (Refer to 9 -
ENGINE/VALVE TIMING/GEAR HOUSING COVER
- INSTALLATION).
(9) Install the vibration damper (Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
INSTALLATION).
(10) Install the fan support/hub assembly and
torque bolts to 24 N´m (18 ft. lbs.).
(11) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(12) Install the cooling fan (Refer to 7 - COOLING/
ENGINE/RADIATOR FAN - INSTALLATION).
(13) Connect battery negative cables.
(14) Start engine and check for oil leaks.
INTAKE MANIFOLD
REMOVAL
(1) Disconnect the battery negative cables.
(2) Remove the charge air cooler outlet tube from
the air inlet housing (Fig. 166).
(3) Remove the engine oil dipstick tube mounting
bolt (Fig. 166). Position dipstick tube to the side.
(4) Disconnect the air grid heater power cables at
the cable mounting studs (Fig. 167).
(5) Remove the four (4) air inlet housing mounting
bolts (Fig. 167) and remove the housing from top of
the heater elements.
(6) Remove the intake air grid heater from the
manifold (Fig. 168).
(7) Remove the high pressure fuel lines.(Refer to
14 - FUEL SYSTEM/FUEL DELIVERY/FUEL LINES
- REMOVAL).
(8) Remove the remaining intake manifold cover-
to-cylinder head bolts.
(9) Remove the intake manifold cover and gasket.
Keep the gasket material and any other material out
of the air intake.
(10) Clean the intake manifold cover and cylinder
head sealing surface.
CLEANING
Clean manifold in solvent and blow dry with com-
pressed air.
Clean cylinder block front and rear gasket surfaces
using a suitable solvent.
The plenum pan rail must be clean and dry (free of
all foreign material).
INSPECTION
Inspect manifold for cracks.Inspect mating surfaces of manifold for flatness
with a straightedge.
INSTALLATION
(1) Using a new gasket, install the intake manifold
cover.
(2) Install the cover-to-cylinder head bolts that do
not hold down the high pressure fuel line support
brackets. Tighten the bolts to 24 N´m (18 ft. lbs.)
torque.
(3) Install the high pressure fuel lines (Refer to 14
- FUEL SYSTEM/FUEL DELIVERY/FUEL LINES -
INSTALLATION).
(4) Install the high pressure fuel line support
bracket-to-intake manifold cover bolts and tighten to
24 N´m (18 ft. lbs.) torque.
(5) Using two (2) new gaskets, install the intake
air grid heater and air inlet housing (Fig. 167). Posi-
tion the ground cable and install and tighten the
bolts to 24 N´m (18 ft. lbs.) torque.
(6) Install and tighten the air intake heater power
supply nuts to 14 N´m (120 in. lbs.) torque.
(7) Install the engine oil dipstick tube and mount-
ing bolt (Fig. 166).
Fig. 166 Charge Air Cooler Air Tube
1 - FRONT WIRING CLIP
2 - GROUND CABLE
3 - TUBE BOLT
4 - ENGINE OIL DIPSTICK TUBE
5 - CLAMPS
6 - AIR TUBE (INT. MAN.-TO-INTERCOOLER)
7 - RUBBER HOSE
8 - AIR INTAKE HOUSING
9 - CABLE BRACKET HOUSING
9 - 184 ENGINE 5.9L DIESELBR/BE
OIL PUMP (Continued)

(8) Position the charge air cooler outlet tube onto
the air inlet housing (Fig. 166). Tighten the clamps
to 8 N´m (72 in. lbs.) torque.(9) Perform the fuel system air bleed procedure
(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY -
STANDARD PROCEDURE).
(10) Connect the battery negative cables.
EXHAUST MANIFOLD
REMOVAL
(1) Disconnect the battery negative cables.
(2) Raise vehicle on hoist.
(3) Disconnect the exhaust pipe from the turbo-
charger elbow (Fig. 169) .
(4) Lower vehicle.
(5) Disconnect the turbocharger air inlet hose (Fig.
170) .
(6) Disconnect the turbocharger oil supply line and
the oil drain tube from the turbocharger (Fig. 171) .
(7) Disconnect the charge air cooler inlet pipe from
the turbocharger (Fig. 171) .
(8) Remove the turbocharger and gasket from the
exhaust manifold.
(9) Remove the cab heater return pipe nut from
the exhaust manifold stud. Position the tube out of
the way.
(10) Remove the exhaust manifold-to-cylinder head
bolts and spacers (Fig. 172) .
(11) Remove the exhaust manifold and gaskets
(Fig. 172) .
CLEANING
Clean the cylinder head and exhaust manifold seal-
ing surfaces with a suitable scraper. Use a Scotch-
BriteŸ pad or equivalent.
Fig. 167 Air Inlet Housing
1 - GROUND STRAP
2 - AIR INTAKE HOUSING
3 - HEATER POWER CABLE MOUNTING STUDS
4 - FUEL LINE BRACKET BOLT
5 - HOUSING BOLTS (4)
Fig. 168 Intake Air Grid Heater
1 - AIR HEATER ELEMENTS
2 - LOWER GASKET
3 - BLOCK
4 - UPPER GASKET
Fig. 169 Exhaust Pipe
1 - EXHAUST PIPE
2 - TURBOCHARGER EXHAUST PIPE
BR/BEENGINE 5.9L DIESEL 9 - 185
INTAKE MANIFOLD (Continued)

(7) Position the charge air cooler inlet pipe to the
turbocharger. With the clamp in position, tighten the
clamp nut to 8 N´m (72 in. lbs.) torque.
(8) Position the air inlet hose to the turbocharger
(Fig. 170). Tighten the clamp to 8 N´m (72 in. lbs.)
torque.
(9) Raise vehicle on hoist.
(10) Connect the exhaust pipe to the turbocharger
(Fig. 169) and tighten the bolts to 34 N´m (25 ft. lbs.)
torque.
(11) Lower the vehicle.
(12) Connect the battery negative cables.
(13) Start the engine to check for leaks.
VALVE TIMING
STANDARD PROCEDURE - TIMING
VERIFICATION
(1) Remove the cylinder head cover.
(2) Remove fuel injector from cylinder number 1.
(3) Remove the crankcase breather from the gear
housing cover.
(4) Using Special Tool 7471B rotate the engine
until the timing mark on the fuel pump gear is
aligned with the TDC mark on the gear housing
cover.
(5) Using a 8 in.x 1/4 in. dowel rod inserted into
cylinder number 1, rock the crankshaft back and
forth to verify piston number 1 is at TDC.
(6) With piston number 1 at TDC the timing mark
on the fuel pump gear should be aligned with the
TDC mark on the gear housing cover. If marks do not
line up, remove the gear housing cover.
(7) With cylinder number still at TDC, inspect the
keyway on the crankshaft gear for proper alignment
(12 o'clock position).
(8) If the keyway is not at 12 o'clock position
replace the crankshaft gear assembly.
(9) If the keyway is at 12 o'clock position, verify
timing mark alignment between the camshaft gear,
crankshaft gear and the fuel pump gear, if not
aligned inspect keyway on camshaft gear.
(10) Inspect keyway on camshaft gear for proper
alignment with the key in the camshaft, if alignment
is off replace the camshaft/gear assembly.
(11) If timing marks alignment is off and no dam-
age is found at either the crankshaft or camshaft
gear keyways, realign timing marks as necessary.
GEAR HOUSING
REMOVAL
(1) Disconnect the battery negative cables.
(2) Raise vehicle on hoist.(3) Partially drain engine coolant into container
suitable for re-use (Refer to 7 - COOLING - STAN-
DARD PROCEDURE).
(4) Lower vehicle.
(5) Remove radiator upper hose.
(6) Disconnect coolant recovery bottle hose from
radiator filler neck and lift bottle off of fan shroud.
(7) Disconnect windshield washer pump supply
hose and electrical connections and lift washer bottle
off of fan shroud.
(8) Remove the fan shroud-to-radiator mounting
bolts.
(9) Remove viscous fan/drive assembly (Refer to 7 -
COOLING/ENGINE/RADIATOR FAN - REMOVAL).
(10) Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(11) Remove the cooling fan support/hub from the
front of the engine (Fig. 173).
(12) Raise the vehicle on hoist.
(13) Remove the crankshaft damper (Fig. 174)
(Refer to 9 - ENGINE/ENGINE BLOCK/VIBRATION
DAMPER - REMOVAL).
(14) Lower the vehicle.
(15) Remove the gear cover-to-housing bolts and
gently pry the cover away from the housing (Fig.
175), taking care not to mar the gasket surfaces.
(16) Remove the fuel injection pump (Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY/FUEL INJEC-
TION PUMP - REMOVAL).
(17) Disconnect the camshaft position sensor con-
nector.
Fig. 173 Fan Support/Hub Assembly - Removal/
Installation
1 - FAN SUPPORT/HUB
2 - FAN PULLEY
BR/BEENGINE 5.9L DIESEL 9 - 187
EXHAUST MANIFOLD (Continued)

(8) Install and tighten the gear housing bolts to 24
N´m (18 ft. lbs.) torque.
(9) Install and tighten the oil pan bolts to 24 N´m
(18 ft. lbs.) torque.
(10) Install the camshaft (Refer to 9 - ENGINE/
ENGINE BLOCK/CAMSHAFT & BEARINGS (IN
BLOCK) - INSTALLATION). Align the crankshaft,
camshaft, and injection pump gear marks as shown
in (Fig. 177).
(11) If a new housing is installed, the camshaft
position sensor must be transferred to the new hous-
ing.
(12) Connect the camshaft position sensor connec-
tor.
(13) Install the injection pump (Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY/FUEL INJEC-
TION PUMP - INSTALLATION).
(14) Obtain a seal pilot/installation tool from a
crankshaft front seal service kit and install the pilot
into the crankshaft front oil seal.
(15) Apply a bead of MopartSilicone Rubber
Adhesive Sealant or equivalent to the gear housing
cover. Be sure to surround all through holes.
(16) Using the seal pilot to align the cover (Fig.
178), install the cover to the housing and install the
bolts. Tighten the bolts to 24 N´m (18 ft. lbs.) torque.
(17) Remove the seal pilot.
(18) Raise the vehicle.
(19) Install the crankshaft damper (Fig. 174)
(Refer to 9 - ENGINE/ENGINE BLOCK/VIBRATION
DAMPER - INSTALLATION).
(20) Lower vehicle.(21) Install the fan support/hub assembly (Fig.
173) and tighten bolts to 24 N´m (18 ft. lbs.) torque.
(22) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(23) Install the cooling fan and shroud together
(Refer to 7 - COOLING/ENGINE/RADIATOR FAN -
INSTALLATION).
(24) Install the windshield washer reservoir to the
fan shroud and connect the washer pump supply
hose and electrical connection.
(25) Install the coolant recovery bottle to the fan
shroud and connect the hose to the radiator filler
neck.
(26) Install the radiator upper hose and clamps.
(27) Add engine oil.
(28) Add coolant (Refer to 7 - COOLING - STAN-
DARD PROCEDURE).
(29) Connect the battery cables.
(30) Start engine and inspect for leaks.
GEAR HOUSING COVER
REMOVAL
(1) Disconnect both battery negative cables.
(2) Raise vehicle on hoist.
(3) Partially drain engine coolant into container
suitable for re-use (Refer to 7 - COOLING - STAN-
DARD PROCEDURE).
(4) Lower vehicle.
(5) Remove radiator upper hose.
(6) Disconnect coolant recovery bottle hose from
radiator filler neck and lift bottle off of fan shroud.
(7) Disconnect windshield washer pump supply
hose and electrical connections and lift washer bottle
off of fan shroud.
Fig. 177 Camshaft/Crankshaft Gear Alignment
Fig. 178 Installing Cover with Seal Pilot
1 - SEAL PILOT
BR/BEENGINE 5.9L DIESEL 9 - 189
GEAR HOUSING (Continued)

SPECIFICATIONS
TORQUE
DESCRIPTION N´m Ft. In.
Lbs. Lbs.
Adjusting StrapÐBolt 23 Ð 200
Air Heater Power SupplyÐ
Nuts14 Ð 124
Air Inlet HousingÐBolts 24 18 Ð
Cab Heater Supply/Return
LineÐNuts24 18 Ð
Exhaust ClampÐNuts 48 35 Ð
Exhaust Manifold to Cylinder
HeadÐBolts
(Diesel Engine) 43 32 Ð
Exhaust Manifold to Cylinder
HeadÐBolts
(5.9L) 31 23 Ð
Exhaust Manifold to Cylinder
HeadÐBolts
(8.0L) 22 Ð 195
Exhaust Pipe to ManifoldÐ
Bolts31 23 Ð
Generator MountingÐBolts 41 30 Ð
Charge Air Cooler
MountingÐBolts2Ð17
Charge Air Cooler DuctÐ
Nuts8Ð72
Heat ShieldÐNuts and Bolts 11 Ð 100
Turbocharger MountingÐ
Nuts32 24 Ð
Turbocharger Oil Drain
TubeÐBolts24 18 Ð
Turbocharger Oil Supply
LineÐFitting15 Ð 133
Turbocharger V-Band
ClampÐNut9Ð75
CATALYTIC CONVERTER -
3.9L/5.2L/5.9L
DESCRIPTION
The stainless steel catalytic converter is located
under the vehicle, integral to the exhaust pipe(s).
OPERATION
The catalytic converter captures and burns any
unburned fuel mixture exiting the combustion cham-
bers during the exhaust stroke of the engine. This
process aids in reducing emissions output.
REMOVAL
(1) Raise and support vehicle.
(2) Saturate the bolts and nuts with heat valve
lubricant. Allow 5 minutes for penetration.
(3) Remove clamps and nuts (Fig. 3) (Fig. 4).
(4) Remove the catalytic converter.
Fig. 3 Catalytic Converter and Exhaust Pipe 3.9L,
5.2L and 5.9L Light Duty ( Federal )
1 - BOLT
2 - EXHAUST PIPE W/CONVERTER
3 - NUT
4 - RETAINER
BR/BEEXHAUST SYSTEM 11 - 5
EXHAUST SYSTEM (Continued)

INSPECTION
Look at the stainless steel body of the converter,
inspect for bulging or other distortion that could be a
result of overheating. If the converter has a heat
shield attached make sure it is not bent or loose.
If you suspect internal damage to the catalyst, tap-
ping the bottom of the catalyst with a rubber mallet
may indicate a damaged core.
INSTALLATION
(1) Assemble converter and clamps loosely in
place.
(2) Install the exhaust pipe onto exhaust mani-
folds, tighten 31 N´m (23 ft. lbs.).
(3) Tighten all clamp nuts to 48 N´m (35 ft. lbs.)
torque.
(4) Lower the vehicle.
(5) Start the engine and inspect for exhaust leaks
and exhaust system contact with the body panels. A
minimum of 25.4 mm (1.0 in.) is required between
exhaust system components and body/frame parts.
Adjust the alignment, if needed.
CATALYTIC CONVERTER - 5.9L
HD/8.0L
DESCRIPTION
The stainless steel catalytic converter is located
under the vehicle, attached to the exhaust pipe(s).
OPERATION
The catalytic converter captures and burns any
unburned fuel mixture exiting the combustion cham-
bers during the exhaust stroke of the engine. This
process aids in reducing emissions output.
REMOVAL
(1) Raise and support vehicle.
(2) Saturate the bolts and nuts with heat valve
lubricant. Allow 5 minutes for penetration.
(3) Remove clamps and nuts (Fig. 5) (Fig. 6).
(4) Remove the catalytic converter.
INSPECTION
Look at the stainless steel body of the converter,
inspect for bulging or other distortion that could be a
result of overheating. If the converter has a heat
shield attached make sure it is not bent or loose.
If you suspect internal damage to the catalyst, tap-
ping the bottom of the catalyst with a rubber mallet
may indicate a damaged core.
Fig. 4 Catalytic Converter and Exhaust Pipe 3.9L,
5.2L and 5.9L Light Duty ( California )
1 - BOLT
2 - RETAINER
3 - EXHAUST MANIFOLD
4 - NUT
5 - MINI CATALYTIC CONVERTER
6 - CATALYTIC CONVERTER WITH PIPES
Fig. 5 Catalytic Converter 5.9L Heavy Duty
1 - DOWN PIPE RIGHT
2 - CLAMP
3 - CLAMP
4 - HANGER ASSY. DUAL CLAMP
5 - MUFFLER
6 - EXTENSION PIPE
7 - CATALYTIC CONVERTER
8 - DOWN PIPE LEFT
11 - 6 EXHAUST SYSTEMBR/BE
CATALYTIC CONVERTER - 3.9L/5.2L/5.9L (Continued)

(4) Connect the DRBIIItto the pressure trans-
ducer following the instructions supplied with the
DRB IIIt.
(5) Enter DRBIIItinto pressure reading mode and
test drive vehicle.
(6) The turbocharger boost pressure must be
between 110 - 138 kpa (16 - 20 psi.). If pressure read-
ings are lower than 110 kpa (16 psi.) inspect for the
following:
²Restricted air inlet system
²Leak in the charge air cooler system (Refer to 11
- EXHAUST SYSTEM/TURBOCHARGER SYSTEM/
CHARGE AIR COOLER AND PLUMBING - DIAG-
NOSIS AND TESTING)
²Turbocharger wastegate broken or misadjusted
²Turbocharger damaged (Refer to 11 - EXHAUST
SYSTEM/TURBOCHARGER SYSTEM/TURBO-
CHARGER - INSPECTION)
TURBOCHARGER
DESCRIPTION
The turbocharger is an exhaust-driven super-
charger which increases the pressure and density of
the air entering the engine. With the increase of air
entering the engine, more fuel can be injected into
the cylinders, which creates more power during com-
bustion.
The turbocharger assembly consists of four (4)
major component systems (Fig. 19) (Fig. 20) :
²Turbine section
²Compressor section
²Bearing housing
²Wastegate
OPERATION
Exhaust gas pressure and energy drive the tur-
bine, which in turn drives a centrifugal compressor
that compresses the inlet air, and forces the air into
the engine through the charge air cooler and plumb-
ing. Since heat is a by-product of this compression,
the air must pass through a charge air cooler to cool
the incoming air and maintain power and efficiency.
Increasing air flow to the engine provides:
²Improved engine performance
²Lower exhaust smoke density
²Improved operating economy
²Altitude compensation
²Noise reduction.
The turbocharger also uses a wastegate (Fig. 21) ,
which regulates intake manifold air pressure and
prevents over boosting at high engine speeds. When
the wastegate valve is closed, all of the exhaust gases
flow through the turbine wheel. As the intake mani-
fold pressure increases, the wastegate actuator opensthe valve, diverting some of the exhaust gases away
from the turbine wheel. This limits turbine shaft
speed and air output from the impeller.
Fig. 19 Turbocharger Operation
1 - TURBINE SECTION
2 - EXHAUST GAS
3 - BEARING HOUSING
4 - COMPRESSOR SECTION
5 - INLET AIR
6 - COMPRESSED AIR TO ENGINE
7 - EXHAUST GAS
8 - EXHAUST GAS TO EXHAUST PIPE
Fig. 20 Turbocharger Wastegate Actuator
1 - TURBOCHARGER
2 - DIAPHRAGM
3 - WASTE GATE ACTUATOR
11 - 14 EXHAUST SYSTEMBR/BE
TURBOCHARGER SYSTEM (Continued)

FRAME SERVICE
SAFETY PRECAUTIONS AND WARNINGS
WARNING: USE EYE PROTECTION WHEN GRIND-
ING OR WELDING METAL, SERIOUS EYE INJURY
CAN RESULT. BEFORE PROCEEDING WITH FRAME
REPAIR INVOLVING GRINDING OR WELDING, VER-
IFY THAT VEHICLE FUEL SYSTEM IS NOT LEAKING
OR IN CONTACT WITH REPAIR AREA, PERSONAL
INJURY CAN RESULT. DO NOT ALLOW OPEN
FLAME TO CONTACT PLASTIC BODY PANELS.
FIRE OR EXPLOSION CAN RESULT. WHEN
WELDED FRAME COMPONENTS ARE REPLACED,
100% PENETRATION WELD MUST BE ACHIEVED
DURING INSTALLATION. IF NOT, DANGEROUS
OPERATING CONDITIONS CAN RESULT. STAND
CLEAR OF CABLES OR CHAINS ON PULLING
EQUIPMENT DURING FRAME STRAIGHTENING
OPERATIONS, PERSONAL INJURY CAN RESULT.
DO NOT VENTURE UNDER A HOISTED VEHICLE
THAT IS NOT SUPPORTED ON SAFETY STANDS,
PERSONAL INJURY CAN RESULT.
CAUTION: Do not reuse damaged fasteners, quality
of repair would be suspect. Do not drill holes in top
or bottom frame rail flanges, frame rail failure can
result. Do Not use softer than Grade 5 bolts to
replace production fasteners, loosening or failure
can result. When using heat to straighten frame
components do not exceed 566ÉC (1050ÉF), metal
fatigue can result. Welding the joints around riveted
cross members and frame side rails can weaken
frame.
FRAME STRAIGHTENING
When necessary, a conventional frame that is bent
or twisted can be straightened by application of heat.
The temperature must not exceed 566ÉC (1050ÉF).
The metal will have a dull red glow at the desired
temperature. Excessive heat will decrease the
strength of the metal and result in a weakened
frame.
Welding the joints around riveted cross members
and frame side rails is not recommended.
A straightening repair process should be limited to
frame members that are not severely damaged. The
replacement bolts, nuts and rivets that are used to
join the frame members should conform to the same
specifications as the original bolts, nuts and rivets.
FRAME REPAIRS
DRILLING HOLES
Do not drill holes in frame side rail top and bottom
flanges, metal fatigue can result causing frame fail-
ure. Holes drilled in the side of the frame rail must
be at least 38 mm (1.5 in.) from the top and bottom
flanges.
Additional drill holes should be located away from
existing holes.
WELDING
Use MIG, TIG or arc welding equipment to repair
welded frame components.
Frame components that have been damaged should
be inspected for cracks before returning the vehicle
to use. If cracks are found in accessible frame com-
ponents perform the following procedures.
(1) Drill a hole at each end of the crack with a 3
mm (O.125 in.) diameter drill bit.
(2) Using a suitable die grinder with 3 inch cut off
wheel, V-groove the crack to allow 100% weld pene-
tration.
(3) Weld the crack.
(4) If necessary when a side rail is repaired, grind
the weld smooth and install a reinforcement channel
(Fig. 9) over the repaired area.
NOTE: If a reinforcement channel is required, the
top and bottom flanges should be 0.250 inches nar-
rower than the side rail flanges. Weld only in the
areas indicated (Fig. 9).
Fig. 9 Frame Reinforcement
1 - .250 IN FROM EDGE
2 - TOP FLANGE
3 - BOTTOM FLANGE
4 - FRAME RAIL
5 - FRAME REPAIR REINFORCEMENT
BR/BEFRAME & BUMPERS 13 - 7
FRAME (Continued)