Insulation:
Removal of the noise shields or any underhood
insulation.
Engine:
Removal or rendering engine speed governor, if the
vehicle has one, inoperative so as to allow engine
speed to exceed manufacturer speci cations.
Fan and Drive:
Removal of fan clutch, if the vehicle has one, or
rendering clutch inoperative.
Removal of the fan shroud, if the vehicle has one.
Air Intake:
Removal of the air cleaner silencer.
Modi cation of the air cleaner.
Exhaust:
Removal of the muffler and/or resonator.
Removal of the exhaust pipes and exhaust pipe
clamps.
Headlamp Aiming
The vehicle has a visual optical headlamp aiming
system. The aim of the headlamps have been preset at
the factory and should need no further adjustment.
However, if the vehicle is damaged in a crash, the aim
of the headlamps may be affected and adjustment
may be necessary.
If oncoming vehicles ash their high beams at you, this
may mean the vertical aim of your headlamps needs
to be adjusted.
It is recommended that the vehicle is taken to your
dealer/retailer for service if the headlamps need to be
adjusted. It is possible however, to re-aim the
headlamps as described.
5-55
Owner Checks and Services on page 6-11tells what
should be checked, when to check it, and what can easily
be done to help keep the vehicle in good condition.
The proper replacement parts, uids, and lubricants to
use are listed inRecommended Fluids and Lubricants
on page 6-15andMaintenance Replacement Parts
on page 6-17. When the vehicle is serviced, make sure
these are used. All parts should be replaced and all
necessary repairs done before you or anyone else
drives the vehicle. We recommend the use of genuine
parts from your dealer/retailer.
Scheduled Maintenance
(Gasoline Engine)
This maintenance section applies to vehicles with a
gasoline engine. For diesel engine vehicles, see the
maintenance schedule section in the DURAMAX
®Diesel
manual.
When the CHANGE ENGINE OIL SOON message
displays, service is required for the vehicle. Have the
vehicle serviced as soon as possible within the next
600 miles (1 000 km). It is possible that, if driving under
the best conditions, the engine oil life system may not
indicate that vehicle service is necessary for over a year.
However, the engine oil and lter must be changed at
least once a year and at this time the system must bereset. Your dealer/retailer has trained service technicians
who will perform this work using genuine parts and reset
the system.
If the engine oil life system is ever reset accidentally,
service the vehicle within 3,000 miles (5 000 km)
since the last service. Remember to reset the oil life
system whenever the oil is changed. SeeEngine Oil Life
System on page 5-18for information on the Engine
Oil Life System and resetting the system.
When the CHANGE ENGINE OIL SOON message
appears, certain services, checks, and inspections are
required. Required services are described in the
following for “MaintenanceI” and “MaintenanceII.”
Generally, it is recommended that the rst service be
MaintenanceI, the second service be MaintenanceII,
and then alternate MaintenanceIand MaintenanceII
thereafter. However, in some cases, MaintenanceII
may be required more often.
MaintenanceI— Use MaintenanceIif the CHANGE
ENGINE OIL SOON message displays within 10 months
since the vehicle was purchased or MaintenanceII
was performed.
MaintenanceII— Use MaintenanceIIif the previous
service performed was MaintenanceI. Always use
MaintenanceIIwhenever the message displays
10 months or more since the last service or if the
message has not come on at all for one year.
6-4
Scheduled Maintenance
Service MaintenanceIMaintenanceII
Change engine oil and lter. SeeEngine Oil on page 5-15. Reset oil life system.
SeeEngine Oil Life System on page 5-18.An Emission Control Service.••
Allison Transmission
®only: Replace external transmission lter at the rst
maintenance service performed on the vehicle.
Lubricate chassis components.See footnote #.••
Visually check for any leaks or damage.See footnote (j).••
Inspect engine air cleaner lter or change indicator (if equipped). If necessary,
replace lter. SeeEngine Air Cleaner/Filter on page 5-19.See footnote (p).•
Rotate tires and check in ation pressures and wear. SeeTire Inspection and
Rotation on page 5-81and “Tire Wear Inspection” inAt Least Once a Month on
page 6-12.••
Inspect brake system.See footnote (a).••
Check engine coolant and windshield washer uid levels and add uid as
needed.••
6-5
