Page 2153 of 5267
2. Tighten the nuts and bolts 11 Nꞏm (100 in. lbs.).
3. Lower the vehicle.
Page 2154 of 5267
MUFFLER
REMOVAL
3.7L/4.7L/5.7L ENGINE
1. Raise and support the vehicle.
2. Saturate the clamp nuts with heat valve lubricant.
Allow 5 minutes for penetration.
3. Disconnect the muffler hangers.
4. Remove clamps and nuts.
5. Remove the muffler.
8.3L ENGINE
1. Raise and support the vehicle.
2. Saturate the clamp nuts with heat valve lubricant.
Allow 5 minutes for penetration.
3. Remove exhaust pipes (Refer to 11 - EXHAUST
SYSTEM/EXHAUST PIPE - REMOVAL).
4. Saturate the clamp nuts with heat valve lubricant.
Allow 5 minutes for penetration.
5. Disconnect the muffler hangers.
6. Remove muffler-to-catalytic converter clamp nuts.
7. Remove the muffler.
Page 2155 of 5267
5.9L DIESEL ENGINE
1. Disconnect the battery negative cables.
2. Raise and support the vehicle.
3. Remove the muffler to tail pipe and extension pipe
clamps.
4. Disconnect the muffler from the hanger isolators.
5. Disconnect the muffler from the tailpipe.
6. Disconnect the muffler from the extension pipe and
remove from the vehicle.
INSTALLATION
3.7L/4.7L/5.7L ENGINE
1. Assemble muffler and clamps loosely to permit
proper alignment of all parts.
2. Connect the muffler hangers.
3.Tightentheclampnutsto54Nꞏm(40ft.lbs.)
torque.
4. Check the exhaust system for contact with the
body panels. A minimum of 25 mm (1.0 in.) is
required between the exhaust system components
and body/frame parts. Make the necessary adjust-
ments, if needed.
5. Lower the vehicle.
6. Start the engine and inspect for exhaust leaks.
Repair exhaust leaks as necessary.
Page 2156 of 5267

8.3L ENGINE
1. Make sure catalytic converters are free of burrs.
2. Assemble muffler and clamps loosely to permit
proper alignment of all parts.
3. Make sure alignment tangs on catalytic converters
seat into alignment slots on mufflers.
4. Connect the muffler hangers.
5. Install exhaust pipes (Refer to 11 - EXHAUST SYS-
TEM/EXHAUST PIPE - INSTALLATION).
6. Check the exhaust system for contact with the
body panels. A minimum of 25.4 mm (1.0 in.) is
required between the exhaust system components
and body/frame parts. Make the necessary adjust-
ments, if needed.
7.Tightentheclampnutsto54Nꞏm(40ft.lbs.)
torque.
8. Lower the vehicle.
9. Start the engine and inspect for exhaust leaks.
Repair exhaust leaks as necessary.
5.9L DIESEL ENGINE
1. Install the muffler hanger rods into the isolators.
2. Install the muffler into the extension pipe.
3. Install the muffler into the tail pipe.
4. Install the exhaust clamps, align the exhaust sys-
tem, and tighten the exhaust clamps to 54 Nꞏm (40
ft. lbs.) torque.
5. Check the exhaust system for contact with the
body panels. A minimum of 25 mm (1.0 in.) is
required between the exhaust system components
and body/frame parts. Make the necessary adjust-
ments, if needed.
6. Lower the vehicle.
7. Connect the battery negative cables.
8. Start the engine and inspect for exhaust leaks.
Repair exhaust leaks as necessary.
Page 2157 of 5267
TA I L P I P E
REMOVAL
3.7L/4.7L/5.7L ENGINE
1. Raise and support the vehicle.
2. Saturate the clamp nuts with heat valve lubricant.
Allow 5 minutes for penetration.
3. Disconnect the exhaust tailpipe support hanger.
4. Remove clamps and nuts.
5. Remove the exhaust tailpipe.
5.9L DIESEL
1. Disconnect the battery negative cables.
2. Raise and support the vehicle.
3. Saturate the clamp nuts with heat valve lubricant.
Allow 5 minutes for penetration.
4. Disconnect the exhaust tailpipe support hanger iso-
lators.
5. Remove the muffler-to-tailpipe clamps.
6. Remove the tailpipe from the vehicle.
Page 2158 of 5267

8.3L ENGINE
1. Raise and support the vehicle.
2. Saturate the clamp nuts with heat valve lubricant.
Allow 5 minutes for penetration.
3. Disconnect the exhaust tailpipe support insulators
(3 and 5).
4. Remove clamps (4) and nuts.
5. Remove the exhaust tailpipes (6).
INSPECTION
Discard rusted clamps, broken or worn supports and attaching parts. Replace a component with original equipment
parts, or equivalent. This will assure proper alignment with other parts in the system and provide acceptable exhaust
noise levels.
INSTALLATION
3.7L/4.7L/5.7L ENGINE
1. Loosely assemble exhaust tailpipe to permit proper
alignment of all parts.
2. Connect the support hangers.
3. Position the exhaust tailpipe for proper clearance
with the underbody parts.
4.Tightenallclampnutsto54Nꞏm(40ft.lbs.)
torque.
5. Check the exhaust system for contact with the
body panels. A minimum of 25 mm (1.0 in.) is
required between the exhaust system components
and body/frame parts. Make the necessary adjust-
ments, if needed.
6. Lower the vehicle.
7. Start the engine and inspect for exhaust leaks.
Repair exhaust leaks as necessary.
Page 2159 of 5267

5.9L DIESEL
1. Install the tailpipe into the muffler.
2. Install the tailpipe hanger rods into the isolators
3. Install the exhaust clamp, align the exhaust sys-
tem, and tighten the clamp 48 Nꞏm (35 ft. lbs.)
torque.
4. Check the exhaust system for contact with the
body panels. A minimum of 25 mm (1.0 in.) is
required between the exhaust system components
and body/frame parts. Make the necessary adjust-
ments, if needed.
5. Lower the vehicle.
6. Connect the battery negative cables.
7. Start the engine and inspect for exhaust leaks.
Repair exhaust leaks as necessary.
8.3L ENGINE
1. Position tailpipes (6) into muffler (2).
2. Make sure alignment tang on tailpipes ( 6) fully
seat into alignment slots on muffler (2).
3. Install insulators (5).
4. Check the exhaust system for contact with the
body panels. A minimum of 25 mm (1.0 in.) is
required between the exhaust system components
and body/frame parts. Make the necessary adjust-
ments, if needed.
5. Tighten all clamp (4) nuts to 54 Nꞏm (40 ft. lbs.)
torque.
6. Lower the vehicle.
7. Start the engine and inspect for exhaust leaks.
Repair exhaust leaks as necessary.
Page 2160 of 5267

TURBOCHARGER SYSTEM
DIAGNOSIS AND TESTING
TURBOCHARGER BOOST PRESSURE
Low turbocharger boost pressure can cause poor engine performance and driveability concerns. The following pro-
cedure will test the turbocharger boost pressure.
Causes of low boost pressure include the following:
Restricted air inlet system
Leak in charge air cooler system
Restricted/high pressure drop across charge air cooler
Damaged turbocharger compressor wheel housing
Turbocharger wastegate stuck open
Excessive exhaust restriction
Causes of excessively high boost pressure include:
Turbocharger wastegate stuck closed
Turbocharger wastegate signal line leaking or damaged
Damaged wastegate command valve O-rings
Wastegate command valve mechanically stuck in actuated position
Several Diagnostic Trouble Codes (DTCs) can be set that will indicate highor low system boost levels. There is a
DTC for circuit faults relating to the electronically controlled wastegate command valve.
(Refer to 11 - EXHAUST SYSTEM/TURBOCHARGER SYSTEM/CHARGE AIR COOLER AND PLUMBING - DIAG-
NOSIS AND TESTING) for diagnosing of low or high boost pressure due to leaks.
NOTE: If oil is present on either the inlet or exhaust side of the turbo charger, check the charge air cooler
for evidence of oil. Clean charge air cooler of any oil before starting the engine. Failure to do this can result
in severe engine damage.