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NOTE:On Canadian vehicles only, if your vehicle is
equipped with All-Season type tires on the front and
On/Off Road type tires mounted on the rear, do not use
a front to back rotation pattern. Instead, rotate your tires
side to side at the recommended intervals.
Dual Rear Wheels
The tires used on dual wheel assemblies should be
matched for wear to prevent overloading one tire in a set.
To check if tires are even, lay a straight edge across all
four tires. The straight edge should touch all the tires.
CAUTION!
4500/5500 Dual Rear Tires have only one approved
direction of rotation. This is to accommodate the
asymmetrical design (tread pattern) of the On/Off
road tire.
(Continued)
Tire Rotation
340 STARTING AND OPERATING
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CAUTION! (Continued)
•When replacing a flat, the spare tire may have to
be remounted on the rim or installed at a different
location to maintain the correct placement of the
tire on the wheel relative to the tire/wheel position
on the vehicle. For example, if the spare is used to
replace an outer rear tire it will have to be re-
mounted on the rim so that the wheel is dished
inward. That way the tread design of asymmetrical
tires will maintain proper position.
FUEL REQUIREMENTS
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 octanefor optimum performance. The use of premium gasoline
is not recommended, as it will not provide any benefit
over regular gasoline in these engines.
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 worldwide 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.
5
STARTING AND OPERATING 341
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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
rear axle systems (GAWR). Total load must be limited so
GVWR and front and rear GAWR are not exceeded.
Payload
The payload of a vehicle is defined as the allowable load
weight a truck can carry, including the weight of the
driver, all passengers, options and cargo.
Gross Axle Weight Rating (GAWR)
The GAWR is the maximum permissible load on the front
and rear axles. The load must be distributed in the cargo
area so that the GAWR of each axle is not exceeded.Each axle GAWR is determined by the components in the
system with the lowest load carrying capacity (axle,
springs, tires or wheels). Heavier axles or suspension
components sometimes specified by purchasers for in-
creased durability does not necessarily increase the vehi-
cle’s GVWR.
Tire Size
The tire size on the Label represents the actual tire size on
your vehicle. Replacement tires must be equal to the load
capacity of this tire size.
Rim Size
This is the rim size that is appropriate for the tire size
listed.
Inflation Pressure
This is the cold tire inflation pressure for your vehicle for
all loading conditions up to full GAWR.
348 STARTING AND OPERATING
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WARNING! (Continued)
•Make certain that the load is secured in the trailer
and will not shift during travel. When trailering
cargo that is not fully secured, dynamic load shifts
can occur that may be difficult for the driver to
control. You could lose control of your vehicle and
have a collision.
•When hauling cargo or towing a trailer, do not
overload your vehicle or trailer. Overloading can
cause a loss of control, poor performance or dam-
age to brakes, axle, engine, transmission, steering,
suspension, chassis structure or tires.
•Safety chains must always be used between your
vehicle and trailer. Always connect the chains to
the hook retainers of the vehicle hitch. Cross the
chains under the trailer tongue and allow enough
slack for turning corners.
(Continued)
WARNING! (Continued)
•Vehicles with trailers should not be parked on a
grade. When parking, apply the parking brake on
the tow vehicle. Put the tow vehicle transmission
in PARK. For four-wheel drive vehicles, make sure
the transfer case is not in NEUTRAL. Always,
block orchockthe trailer wheels.
•GCWR must not be exceeded.
•Total weight must be distributed between the tow
vehicle and the trailer such that the following four
ratings are not exceeded:
1. GVWR
2. GTW
3. GAWR
4. Trailer tongue weight rating for the trailer hitch
utilized (This requirement may limit the ability to
always achieve the 10% to 15% range of tongue
weight as a percentage of total trailer weight).
356 STARTING AND OPERATING
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Towing Requirements – Tires
•
Do not attempt to tow a trailer with less than the full
size spare tire.
•Proper tire inflation pressures are essential to the safe
and satisfactory operation of your vehicle. Refer to
“Tires – General Information” in “Starting and Oper-
ating” for proper tire inflation procedures.
•Check the trailer tires for proper tire inflation pres-
sures before trailer usage.
•Check for signs of tire wear or visible tire damage
before towing a trailer. Refer to “Tires – General
Information” in “Starting and Operating” for the
proper inspection procedure.
•When replacing tires, refer to “Tires – General Infor-
mation” in “Starting and Operating” for proper tirereplacement procedures. Replacing tires with a higher
load carrying capacity will not increase the vehicle’s
GVWR and GAWR limits.
Towing Requirements – Trailer Brakes
•
Donotinterconnect the hydraulic brake system or
vacuum system of your vehicle with that of the trailer.
This could cause inadequate braking and possible
personal injury.
•An electronically actuated trailer brake controller is
required when towing a trailer with electronically
actuated brakes. When towing a trailer equipped with
a hydraulic surge actuated brake system, an electronic
brake controller is not required.
•Trailer brakes are recommended for trailers over
1,000 lbs (454 kg) and required for trailers in excess of
2,000 lbs (907 kg).
5
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3. When a trailer with electric brakes is plugged in, the
GAIN setting will illuminate.
4. Use the GAIN adjustment (+/-) buttons to increase or
decrease the GAIN setting to the desired starting point. A
GAIN setting of 6 is a good starting point for heavier
loads.
5. In a traffic-free environment, tow the trailer on a dry,
level surface at a speed of 20–25 mph (30–40 km/h) and
squeeze the manual brake control lever completely.
6. If the trailer wheels lockup (indicated by squealing
tires), reduce the GAIN setting; if the trailer wheels turn
freely, increase the GAIN setting.
Repeat Steps 5 and 6 until the GAIN setting is at a point
just below trailer wheel lockup. If towing a heavier
trailer, trailer wheel lockup may not be attainable even
with the maximum GAIN setting of 10.EVIC Display Messages
The trailer brake control interacts with the Electronic
Vehicle Information Center (EVIC). Display messages,
along with a single chime, will be displayed when a
malfunction is determined in the trailer connection,
trailer brake control, or on the trailer. Refer to “Electronic
Vehicle Information Center (EVIC)” in “Understanding
Your Instrument Panel” for further information.
CAUTION!
The ITBM module has been designed and verified
for electric trailer brakes. Connecting a trailer that is
not compatible with the ITBM system may result in
reduced or complete loss of trailer braking. There
may be a increase in stopping distance or trailer
instability which could result in damage to your
vehicle, trailer, or other property.
5
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WARNING! (Continued)
•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 Location6
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WARNING! (Continued)
•If working on or near a roadway, be extremely
careful of motor traffic.
•To assure that spare tires, flat or inflated, are
securely stowed, spares must be stowed with the
valve stem facing the ground.
CAUTION!
Do not attempt to raise the vehicle by jacking on
locations other than those indicated in the Jacking
Instructions for this vehicle.
1. If equipped, remove the spare wheel, jack, and tools
from storage.
2. Using the wheel wrench, loosen, but do not remove,
the wheel nuts by turning them counterclockwise one
turn while the wheel is still on the ground.
3. When changing the front wheel, assemble the jack
drive tube to the jack and connect the drive tube to the
extension tube. Place the jack under the axle as close to
the tire as possible with the drive tubes extending to the
front. Connect the jack tube extension and wheel wrench.
Jack Warning Label
384 WHAT TO DO IN EMERGENCIES