GMC CHEVROLET Silverado 6500HD 2019 Owner's Manual page 395

394 Service and Maintenance
Frame
GM Truck chassis are manufactured
with frame rails of high strength
steel, and each must be handled in
a specific manner to ensure
maximum service life. Before
attempting frame repair or
modification, consult the service
manual or your dealer.
Noise Emissions -
Maintenance, Use, and Repair
Instructions for Proper
Maintenance
In order to comply with federal
exterior noise regulations, your
vehicle may be equipped with noise
emission items that must be
properly maintained, used, and
repaired. Depending upon the
vehicle configuration, it may
incorporate all or some of the
following:
Air Intake System
Air Cleaner should be
inspected and its location should
not be altered. Do not alter inlet
and outlet piping.
Body
Wheel Well splash shields,
cab shields, and underhood
insulation should be inspected
for deterioration, dislocation, and
orientation and repaired or
replaced as necessary.
Cooling System
Check fan for damage to blades.
Replace, if damaged, with
manufacturer's recommended
parts. Inspect for fan-to-shroud
interference and any damage to
shroud, such as cracks and
holes.
Fan speed ratio should not be
changed and fan spacer
dimensions and position should
not be altered.
Inspect for proper operation of
fan clutch, making sure that the
fan is disengaged when cooling
of engine is not required.
Engine Noise Shields/Blankets
Engine valve covers, oil pans,
and block covers are made to
damp out engine mechanical
noise and, if needed, should be
replaced with original equipment
parts.
Exhaust System
Inspect for leaks at various joint
connections and tighten clamps.
Make visual inspection for
cracks or holes in muffler and
tailpipe. Always replace with
manufacturer's recommended
parts. Tailpipe elbow or offset
tailpipe orientation must not be
changed from standard position
as originally received.
To prevent abnormal changes in
vehicle sound level, it is
necessary for the owner to
perform inspections and
necessary maintenance at the
intervals shown in the
maintenance schedules, and
record them on the maintenance
record form provided.