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Information placard for the size designation of your tire.
The service description and load identification will be
found on the original equipment tire. Failure to use
equivalent replacement tires may adversely affect the
safety, handling, and ride of your vehicle. We recommend
that you contact your original equipment or an autho-
rized tire dealer with any questions you may have on tire
specifications or capability.WARNING!
•Do not use a tire, wheel size or rating other than
that specified for your vehicle. Some combinations
of unapproved tires and wheels may change sus-
pension dimensions and performance characteris-
tics, resulting in changes to steering, handling, and
braking of your vehicle. This can cause unpredict-
able handling and stress to steering and suspen-
sion components. You could lose control and have
an accident resulting in serious injury or death.
Use only the tire and wheel sizes with load ratings
approved for your vehicle.(Continued)
STARTING AND OPERATING 275
5
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FUEL REQUIREMENTS
5.7L Gas Engine
The 5.7L engine is designed to meet all
emissions regulations and provide satisfac-
tory fuel economy and performance when
using high quality unleaded gasoline hav-
ing an octane range of 87 to 89. The manu-
facturer recommends the use of 89 octane
for optimum performance. The use of premium gasoline
is not recommended. Under normal conditions, the use of
premium gasoline will not provide a benefit over high
quality regular and mid-grade gasolines, and in some
circumstances may result in poorer performance.
Light spark knock at low engine speeds is not harmful to
your engine. However, continued heavy spark knock at
high speeds can cause damage and immediate service is
required. Poor quality gasoline can cause problems such as hard
starting, stalling and hesitations. If you experience these
symptoms, try another brand of “regular” gasoline be-
fore considering service for the vehicle.
Over 40 auto manufacturers world-wide have issued and
endorsed consistent gasoline specifications (the World-
wide Fuel Charter, WWFC) to define fuel properties
necessary to deliver enhanced emissions, performance
and durability for your vehicle. We recommend the use
of gasolines that meet the WWFC specifications if they
are available.
Reformulated Gasoline
Many areas of the country require the use of cleaner
burning gasoline referred to as “Reformulated Gasoline.”
Reformulated gasolines contain oxygenates, and are spe-
cifically blended to reduce vehicle emissions and im-
prove air quality.
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allowed in the United States. MMT is prohibited in
Federal and California reformulated gasoline.
Materials Added To Fuel
All gasolines sold in the United States are required to
contain effective detergent additives. Use of additional
detergents or other additives is not needed under normal
conditions and would result in unnecessary cost. There-
fore, you should not have to add anything to the fuel.
Fuel System Cautions
CAUTION!
Follow these guidelines to maintain your vehicle’s
performance:
•The use of leaded gas is prohibited by Federal law.
Using leaded gasoline can impair engine perfor-
mance, and damage the emission control system.(Continued)
CAUTION! (Continued)
•An out-of-tune engine, or certain fuel or ignition
malfunctions, can cause the catalytic converter to
overheat. If you notice a pungent burning odor or
some light smoke, your engine may be out of tune
or malfunctioning and may require immediate
service. Contact your authorized dealer for service
assistance.
•When pulling a heavy load or driving a fully
loaded vehicle when the humidity is low and the
temperature is high, use a premium unleaded fuel
to help prevent spark knock. If spark knock per-
sists, lighten the load, or engine piston damage
may result.(Continued)
STARTING AND OPERATING 283
5
Page 317 of 429
JACKING AND TIRE CHANGING
WARNING!
•Being under a jacked-up vehicle is dangerous. The
vehicle could slip off the jack and fall on you. You
could be crushed. Never put any part of your body
under a vehicle that is on a jack. Never start or run
the engine while the vehicle is on a jack. If you
need to get under a raised vehicle, take it to a
service center where it can be raised on a lift.
•The jack is designed to use as a tool for changing
tires only. The jack should not be used to lift the
vehicle for service purposes. The vehicle should
be jacked on a firm level surface only. Avoid ice or
slippery areas.
3500 Models — If Equipped
The jack and jack tools are stored under the front
passenger seat. Lift the flap on the side of the seat for
access.
Remove the jack and tools by removing the wing bolt and
sliding the assembly from under the seat.
Jack Location
WHAT TO DO IN EMERGENCIES 315
6
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WARNING!
After using the jack and tools, always reinstall them
in the original carrier and location. While driving
you may experience abrupt stopping, rapid accelera-
tion, or sharp turns. A loose jack, tools, bracket or
other objects in the vehicle may move around with
force, resulting in serious injury.
4500/5500 Models
These vehicles do not come equipped with a jack.
NOTE:Jacking and tire changing on 4500/5500 models
should be performed by an authorized dealer, or knowl-
edgeable service personnel with the appropriate heavy
duty equipment, like a tire service company.
Preparations For Jacking
1. Park the vehicle on a firm level surface. Avoid ice or
slippery areas.
WARNING!
Do not attempt to change a tire on the side of the
vehicle close to moving traffic. Pull far enough off
the road to avoid the danger of being hit when
operating the jack or changing the wheel.
2. Set the parking brake.
3. Place the shift lever into PARK (automatic transmis-
sion) or REVERSE (manual transmission). On 4-Wheel
drive vehicles, shift the transfer case to the “4L” position.
4. Turn OFF the ignition.
5. Turn on the Hazard Warning flasher.
316 WHAT TO DO IN EMERGENCIES
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4. By rotating the wheel wrench clockwise, raise the
vehicle until the wheel just clears the surface.
WARNING!
Raising the vehicle higher than necessary can make
the vehicle unstable and cause an accident. It could
slip off the jack and hurt someone near it. Raise the
vehicle only enough to remove the tire.
5. Remove the wheel nuts and pull the wheel off. Install
the spare wheel and wheel nuts with the cone shaped end
of the nuts toward the wheel on single rear wheel (SRW)
models. On dual rear wheel models (DRW) the lug nuts
are a two-piece assembly with a flat face. Lightly tighten
the nuts. To avoid risk of forcing the vehicle off the jack,
do not fully tighten the nuts until the vehicle has been
lowered. 6. Using the wheel wrench, finish tightening the nuts
using a crisscross pattern. Correct nut tightness is 135 ft
lbs (183 N·m) torque for single rear wheel (SRW) models
and 145 ft lbs (197 N·m) for dual rear wheel models. If in
doubt about the correct tightness, have them checked
with a torque wrench by your authorized dealer or at a
service station.
WARNING!
A loose tire or jack thrown forward in a collision or
hard stop could injure someone in the vehicle. Al-
ways stow the jack parts and the extra tire and wheel
in the places provided.
320 WHAT TO DO IN EMERGENCIES
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MAINTAINING YOUR VEHICLE
CONTENTS
\2Engine Compartment— 5.7L .............. 335
\2 Onboard Diagnostic System (OBD II) ....... 336
\4 Loose Fuel Filler Cap Message ........... 336
\2 Replacement Parts ..................... 337
\2 Dealer Service ........................ 337
\2 Maintenance Procedures ................. 338
\4 Engine Oil ......................... 338
\4 Engine Air Cleaner Filter ............... 340
\4 Maintenance Free Battery .............. 341 \4
Air Conditioner Maintenance ............ 342
\4 Body Lubrication .................... 343
\4 Windshield Wiper Blades ............... 344
\4 Adding Washer Fluid ................. 344
\4 Exhaust System ..................... 345
\4 Cooling System ..................... 348
\4 Brake System ....................... 353
\4 Rear Axle And 4X4 Front Driving Axle Fluid
Level ............................. 355
7
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ONBOARD DIAGNOSTIC SYSTEM (OBD II)
Vehicles with 5.7L engines are equipped with a sophisti-
cated onboard diagnostic system called OBD II. This
system monitors the performance of the emissions, en-
gine, and automatic transmission control systems. When
these systems are operating properly, your vehicle will
provide excellent performance and fuel economy, as well
as engine emissions well within current government
regulations.
If any of these systems require service, the OBD II system
will turn on the Malfunction Indicator Light (MIL). It will
also store diagnostic codes and other information to
assist your service technician in making repairs. Al-
though your vehicle will usually be driveable and not
need towing, see your authorized dealer for service as
soon as possible.CAUTION!
Prolonged driving with the MIL on could cause
further damage to the emission control system. It
could also affect fuel economy and driveability. The
vehicle must be serviced before any emissions tests
can be performed.
If the MIL is flashing, severe catalytic converter
damage and power loss will soon occur. Immediate
service is required.
Loose Fuel Filler Cap Message
If the vehicle’s diagnostic system determines that the fuel
filler cap is loose, improperly installed, or damaged, a
gASCAP message will be displayed in the instrument
cluster. Tighten the gas cap until a “clicking” sound is
heard. This is an indication that the gas cap is properly
tightened. Press the odometer reset button to turn the
message off. If the problem persists, the message will
336 MAINTAINING YOUR VEHICLE