Page 1537 of 2627

(6) Full load boost pressure at rated speed will be
158 - 186 kPa (23 - 27 psi.) depending on engine hp
rating.. If pressure readings are are not within this
range 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
²Restricted/high pressure drop across charge air
cooler
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. 14) (Fig. 15) :²Turbine section
²Compressor section
²Bearing housing
²Wastegate
Fig. 13 INTAKE MANIFOLD TO AIR INLET DUCT
RUBBER SLEEVE
1 - INTAKE MANIFOLD AIR INLET
2 - CLAMPS
3 - AIR INLET DUCT
4 - AIR INLET DUCT RUBBER SLEEVE
Fig. 14 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. 15 Turbocharger Wastegate Actuator
1 - TURBOCHARGER
2 - DIAPHRAGM
3 - WASTE GATE ACTUATOR
11 - 12 EXHAUST SYSTEMDR
TURBOCHARGER SYSTEM (Continued)
Page 1538 of 2627

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. 16),
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 opens
the valve, diverting some of the exhaust gases away
from the turbine wheel. This limits turbine shaft
speed and air output from the impeller.
The turbocharger is lubricated by engine oil that is
pressurized, cooled, and filtered. The oil is delivered
to the turbocharger by a supply line that is tapped
into the oil filter head. The oil travels into the bear-
ing housing, where it lubricates the shaft and bear-
ings (Fig. 17). A return pipe at the bottom of the
bearing housing, routes the engine oil back to the
crankcase.
The most common turbocharger failure is bearing
failure related to repeated hot shutdowns with inad-
equate ªcool-downº periods. A sudden engine shut
down after prolonged operation will result in the
transfer of heat from the turbine section of the tur-
bocharger to the bearing housing. This causes the oil
to overheat and break down, which causes bearing
and shaft damage the next time the vehicle is
started.
Letting the engine idle after extended operation
allows the turbine housing to cool to normal operat-
ing temperature. The following chart should be used
as a guide in determining the amount of engine idle
time required to sufficiently cool down the turbo-
charger before shut down, depending upon the type
of driving and the amount of cargo.
Fig. 16 Wastegate Operation
1 - SIGNAL LINE
2 - EXHAUST BYPASS VALVE
3 - WASTEGATE
4 - EXHAUST
5 - TURBINE
DREXHAUST SYSTEM 11 - 13
TURBOCHARGER (Continued)
Page 1539 of 2627

TURBOCHARGER(COOL DOWN(CHART
Driving
ConditionLoad Turbo-
charger
Temper-
atureIdle Time (in
minutes)
Before Shut
Down
Stop & Go Empty Cool Less than 1
Stop & Go Medium Warm 1
Highway
SpeedsMedium Warm 2
City Traffic Max.
GCWRWarm 3
Highway
SpeedsMax.
GCWRWarm 4
Uphill Grade Max.
GCWRHot 5
REMOVAL
(1) Disconnect the battery negative cables.
(2) Raise vehicle on hoist.
(3) Disconnect the exhaust pipe from the turbo-
charger elbow(Refer to 11 - EXHAUST SYSTEM/EX-
HAUST PIPE - REMOVAL).
(4) Remove the bolts from the turbocharger oil
drain tube.
(5) Lower vehicle.
(6) Disconnect the turbocharger air inlet hose (Fig.
18).
(7) Disconnect the turbocharger oil supply line
from the turbocharger (Fig. 19).
(8) Disconnect the charge air cooler inlet pipe from
the turbocharger compressor outlet (Fig. 19).
Fig. 17 Turbocharger Oil Supply and Drain
1 - BEARINGS
2 - OIL SUPPLY (FROM FILTER HEAD)
3 - OIL RETURN (TO SUMP)
Fig. 18 Turbocharger Air Inlet Hose
1 - AIR INLET TUBE
2 - AIR FILTER HOUSING
3 - TURBOCHARGER
Fig. 19 Oil Supply Line and Charge Air Cooler Inlet
Duct
1 - TURBOCHARGERR EXHAUST ELBOW
2 - TURBOCHARGER
3 - OIL SUPPLY LINE
4 - AIR INLET TUBE
5 - TURBOCHARGER COMPRESSOR OUTLET
6 - OIL DRAIN LINE
11 - 14 EXHAUST SYSTEMDR
TURBOCHARGER (Continued)
Page 1540 of 2627

(9) Remove the turbocharger and gasket from the
exhaust manifold.
(10) If the turbocharger is not to be installed
immediately, cover the opening to prevent material
from entering into the manifold.
(11) If replacing the turbocharger, transfer the tur-
bocharger oil supply fitting to the new assembly.
Tighten fitting to 36 N´m (27 ft. lbs.).
(12) Clean and inspect the sealing surface.
CAUTION: The turbocharger is only serviced as an
assembly. Do not attempt to repair the turbocharger
as turbocharger and/or engine damage can result.
CLEANING
WARNING: To prevent damage or personal injury,
do not use a combustable cleaner to clean the tur-
bocharger.
Clean the turbocharger and exhaust manifold
mounting surfaces with a suitable scraper.
INSPECTION
Visually inspect the turbocharger and exhaust
manifold gasket surfaces. Replace stripped or eroded
mounting studs.
(1) Visually inspect the turbocharger for cracks.
The following cracks are NOT acceptable:
²Cracks in the turbine and compressor housing
that go completely through.
²Cracks in the mounting flange that are longer
than 15 mm (0.6 in.).
²Cracks in the mounting flange that intersect
bolt through-holes.
²Two (2) Cracks in the mounting flange that are
closer than 6.4 mm (0.25 in.) together.
(2) Visually inspect the impeller and compressor
wheel fins for nicks, cracks, or chips. Note: Some
impellers may have a factory placed paint mark
which, after normal operation, appears to be a crack.
Remove this mark with a suitable solvent to verify
that it is not a crack.
(3) Visually inspect the turbocharger compressor
housing for an impeller rubbing condition (Fig. 20).
Replace the turbocharger if the condition exists.
(4) Measure the turbocharger axial end play:
(a) Install a dial indicator as shown in (Fig. 21).
Zero the indicator at one end of travel.
(b) Move the impeller shaft fore and aft and
record the measurement. Allowable end play is
0.026 mm (0.0001 in.) MIN. and 0.127 mm (0.005
in.) MAX. If the recorded measurement falls out-
side these parameters, replace the turbocharger
assembly.(5) Measure the turbocharger bearing radial clear-
ance:
(a) Insert a narrow blade or wire style feeler
gauge between the compressor wheel and the hous-
ing (Fig. 22).
(b) Gently push the compressor wheel toward
the housing and record the clearance.
(c) With the feeler gauge in the same location,
gently push the compressor wheel away from the
housing and again record the clearance.
(d) Subtract the smaller clearance from the
larger clearance. This is the radial bearing clear-
ance.
(e) Allowable radial bearing clearance is 0.33
mm (0.013 in.) MIN. and 0.50 mm (0.020 in.) MAX.
If the recorded measurement falls outside these
specifications, replace the turbocharger assembly.
INSTALLATION
(1) Install the turbocharger. Apply anti-seize to the
studs and then tighten the turbocharger mounting
nuts to 43 N´m (32 ft. lbs.) torque.
Fig. 20 Inspect Compressor Housing for Impeller
Rubbing Condition
Fig. 21 Measure Turbocharger Axial End Play
DREXHAUST SYSTEM 11 - 15
TURBOCHARGER (Continued)
Page 1541 of 2627

(2)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.
(3) Install and tighten the oil supply line to 24
N´m (18 ft. lbs.) torque.
(4) 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.
(5) Position the air inlet hose to the turbocharger
(Fig. 18). Tighten the clamp to 11 N´m (95 in. lbs.)
torque.
(6) Raise vehicle on hoist.
(7) Using a new gasket, install the oil drain tube
to the turbocharger (Fig. 19). Tighten the drain tube
bolts to 24 N´m (18 ft. lbs.) torque.
(8) Tighten the oil drain tube clamps to 8 N´m (71
in. lbs.).
(9) Connect the exhaust pipe to the turbocharger
and tighten the bolts to 11.3 N´m (100 in. lbs.)
torque.
(10) Lower the vehicle.
(11) Connect the battery negative cables.
(12) 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 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 tur-
bocharger inlet. Tighten tool clamp to 8 N´m (72 in.
lbs.).
Fig. 22 Measure Turbocharger Bearing Radial
Clearance
1 - FEELER GAUGE
Fig. 23 Intake Air Circulation
1 - CHARGE AIR COOLER
2 - AIRFILTER
3 - TURBOCHARGER
11 - 16 EXHAUST SYSTEMDR
TURBOCHARGER (Continued)
Page 1542 of 2627

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
Tool 9022 Adapter. Set air pressure to a Maximum 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.
(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/
PLUMBING/A/C CONDENSER - INSTALLATION).
Recharge A/C system (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - STANDARD PRO-
CEDURE).
(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
DREXHAUST SYSTEM 11 - 17
CHARGE AIR COOLER AND PLUMBING (Continued)
Page 1543 of 2627
Page 1544 of 2627

FRAMES & BUMPERS
TABLE OF CONTENTS
page page
BUMPERS
SPECIFICATIONS - TORQUE...............1
FRONT AIR DAM
REMOVAL.............................2
INSTALLATION..........................2
FRONT BUMPER
REMOVAL.............................2
INSTALLATION..........................2
FRONT FASCIA
REMOVAL.............................2
INSTALLATION..........................3
REAR BUMPER
REMOVAL.............................3
INSTALLATION..........................4
FRAME
WARNING
SAFETY PRECAUTIONS AND WARNINGS . . . 4
STANDARD PROCEDURE
STANDARD PROCEDURE - LIGHT DUTY
FRONT FRAME RAIL TIP REPLACEMENT....4
STANDARD PROCEDURE - HYDROFORM
FENDER RAIL REPAIR.................11
STANDARD PROCEDURE - REAR FRAME
H-SECTION REPLACEMENT.............13SPECIFICATIONS
SPECIFICATIONS - WELD PROCESS......15
SPECIFICATIONS - FRAME DIMENSIONS . . . 16
SPECIFICATIONS - TORQUE............22
FRONT CROSSMEMBER
REMOVAL.............................22
INSTALLATION.........................22
FRONT SKID PLATE
REMOVAL.............................23
INSTALLATION.........................23
FRONT TOW HOOK ASSEMBLY
REMOVAL.............................23
INSTALLATION.........................23
TRANSMISSION CROSSMEMBER
REMOVAL.............................24
INSTALLATION.........................24
TRAILER HITCH
REMOVAL.............................25
INSTALLATION.........................25
TRANSFER CASE SKID PLATE
REMOVAL.............................26
INSTALLATION.........................26
BUMPERS
SPECIFICATIONS - TORQUE
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Front bumper center bracket nuts 95 70 Ð
Front bumper stud plate nuts 95 70 Ð
License plate hitch reinforcement bolts 54 40 Ð
Rear bumper support bracket stud plate nuts 54 40 Ð
Rear bumper support bracket to hitch bolts 54 40 Ð
Rear bumper to hitch bolts 54 40 Ð
DRFRAMES & BUMPERS 13 - 1