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CATALYTIC CONVERTER
The catalytic converter requires the use of unleaded fuel
only. Leaded gasoline will destroy the effectiveness of the
catalyst as an emission control device. Under normal
operating conditions, the catalytic converter will not
require maintenance. However, you must keep the en-
gine maintained to assure proper operation and prevent
possible damage.
NOTE:Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.CAUTION!
Damage to the catalytic converter can result if your
vehicle is not kept in proper operating condition. In
the event of engine malfunction, particularly involv-
ing engine misfire or other apparent loss of perfor-
mance, have your vehicle serviced promptly. Contin-
ued operation of your vehicle with a severe
malfunction could cause the converter to overheat,
resulting in possible damage to the converter and
vehicle.
As with any vehicle, do not park or operate this vehicle in
areas where combustible materials such as grass or leaves
can come in contact with a hot exhaust system.
A scorching odor may be detected if you continue to run
a malfunctioning engine. The odor may indicate severe
and abnormal catalyst overheating. If this occurs, the
266 STARTING AND OPERATING
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vehicle should be stopped, the engine shut off and the
vehicle allowed to cool. Service, including a tune-up to
manufacturer's specifications should be obtained imme-
diately.
To minimize the possibility of catalyst damage:
²Do not try to start the engine by pushing or towing the
vehicle.
²Do not idle the engine with any spark plug wires
disconnected or removed.
²Do not idle the engine for prolonged periods during
very rough idle or malfunctioning operating condi-
tions.
²Do not allow vehicle to run out of fuel.
VEHICLE LOADING
Certification Label
As required by National Highway Traffic Safety Admin-
istration Regulations, your vehicle has a certification
label affixed to the driver's side door or pillar.
This label contains the month and year of manufacture,
Gross Vehicle Weight Rating (GVWR), Gross Axle Weight
Rating (GAWR) front and rear, and Vehicle Identification
Number (VIN). A Month-Day-Hour (MDH) number is
included on this label and indicates the Month, Day and
Hour of manufacture. The bar code that appears on the
bottom of the label is your Vehicle Identification Number
(VIN).
Gross Vehicle Weight Rating (GVWR)
The GVWR is the total permissible weight of your vehicle
including driver, passengers, vehicle, options and cargo.
The label also specifies maximum capacities of front and
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Loading
The actual total weight and the weight of the front and
rear of your vehicle at the ground can best be determined
by weighing it when it is loaded and ready for operation.
The entire vehicle should first be weighed on a commer-
cial scale to insure that the GVWR has not been exceeded.
The weight on the front and rear of the vehicle should
then be determined separately to be sure that the load is
properly distributed over front and rear axle. Weighing
the vehicle may show that the GAWR of either the front
or rear axles has been exceeded but the total load is
within the specified GVWR. If so, weight must be shifted
from front to rear or rear to front as appropriate until the
specified weight limitations are met. Store the heavier
items down low and be sure that the weight is distributed
equally. Stow all loose items securely before driving.Improper weight distributions can have an adverse effect
on the way your vehicle steers and handles and the way
the brakes operate.
CAUTION!
Do not load your vehicle any heavier than the
GVWR or the maximum front and rear GAWR. If
you do, parts on your vehicle can break, or it can
change the way your vehicle handles. This could
cause you to lose control. Also overloading can
shorten the life of your vehicle.
An EXAMPLE of a loaded vehicle is shown in the
following chart. Note that neither GVWR nor GAWR
capabilities are exceeded. Overloading can cause poten-
tial safety hazards and shorten service life.
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²Air ConditioningÐturn it off temporarily.
²Hilly TerrainÐTurn overdrive off.
See Cooling System Operating information in the Service
and Maintenance section of this manual for more infor-
mation.
Automatic Transmission Oil Temperature Warning
Light
All vehicles with automatic transmissions are equipped
with a transmission sump oil temperature sensor and
warning light. If elevated transmission temperatures are
encountered, the engine controller will select the most
desirable gear until the transmission temperatures are
reduced. If transmission oil temperatures continue to
rise, a warning light located in the instrument cluster will
illuminate. If this should occur, stop the vehicle, shift to
Neutral, and run the engine at idle or faster until the light
goes off.
Towing With An Automatic Transmission
Vehicles equipped with an automatic transmission may
shift into and out of Overdrive, or a lower gear, when
driving in hilly areas, when heavily loaded, or when
towing into heavy winds.
When this condition occurs, select TOW/HAUL mode or
shift into a lower gear to prevent excessive transmission
wear and/or overheating, and to provide better engine
braking.
NOTE:Do not exceed the following RPM while manu-
ally downshifting:
²5800 rpm with 3.7L engines.
²5800 rpm with 4.7L engines.
²5600 rpm with 5.7L engines.
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WARNING!
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, unless suitable sup-
ports are placed under the vehicle as a safety mea-
sure. The vehicle should be jacked on a firm level
surface only. Avoid ice or slippery areas.
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.2500/3500 Model Vehicles
WHAT TO DO IN EMERGENCIES 297
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Tire Changing Procedure
WARNING!
Getting under a jacked-up vehicle is dangerous. The
vehicle could slip off the jack and fall on you. You
could be crushed. Never get 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.
Do not raise this vehicle using a bumper jack. The jack is
designed as a tool for changing tires on this vehicle only.
It is not recommended that the jack be used for service
purposes or to lift more than one wheel at a time.
Preparations
Park the vehicle on a firm level surface, avoiding ice or
slippery areas. Set the parking brake and place the gear
selector in PARK (automatic transmission) or REVERSE
(manual transmission). On four-wheel drive vehicles,
shift the transfer case to the ª4Lº position.
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.
302 WHAT TO DO IN EMERGENCIES
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NOTE:If the 2500/3500 bottle jack will not lower by
turning the dial (thumb wheel) by hand, it may be
necessary to use the jack drive tube in order to lower the
jack.
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 endof the nuts toward the wheel on 2500/3500 single rear
wheel (SRW) models. On 3500 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 2500/3500 single rear wheel
(SRW) models and 145 ft. lbs. (197 N´m) for 3500 dual rear
wheel models. If in doubt about the correct tightness,
have them checked with a torque wrench by your dealer
or at a service station.
WHAT TO DO IN EMERGENCIES 307
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MAINTAINING YOUR VEHICLE
CONTENTS
mEngine CompartmentÐ 3.7L/4.7L...........322
mEngine CompartmentÐ 5.7L...............323
mOnboard Diagnostic System (OBD II).........324
mEmissions Inspection And Maintenance
Programs............................324
mDealer Service.........................326
mReplacement Parts......................327
mMaintenance Procedures..................327
NAir Conditioner Maintenance.............327NEngine Oil..........................329
NEngine Oil Filter......................333
NDrive Belts Ð Check Condition And
Tensioner...........................333
NSpark Plugs.........................333
NEngine Air Cleaner Filter................334
NEngine Fuel Filter.....................334
NCatalytic Converter....................335
NEmission-Related Components............336
7