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Tire Size
The tire size on the Vehicle Certification 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.
Curb Weight
The curb weight of a vehicle is defined as the total weight
of the vehicle with all fluids, including vehicle fuel, at full
capacity conditions, and with no occupants or cargo
loaded into the vehicle. The front and rear curb weight
values are determined by weighing your vehicle on a
commercial scale before any occupants or cargo are
added.
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 the front and rear axle. Weigh-
ing 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
5
STARTING AND OPERATING 647
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Towing Requirements — Tires
•Do not attempt to tow a trailer while using a compact
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 tire
replacement procedures. Replacing tires with a higher
load carrying capacity will not increase the vehicle’s
GVWR and GAWR limits.
Towing Requirements — Trailer Brakes
WARNING!
•Do not connect trailer brakes to your vehicle’s
hydraulic brake lines. It can overload your brake
system and cause it to fail. You might not have
brakes when you need them and could have an
accident.
•Towing any trailer will increase your stopping
distance. When towing you should allow for addi-
tional space between your vehicle and the vehicle
in front of you. Failure to do so could result in an
accident.
660 STARTING AND OPERATING
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NOTE:Dual wheels are flat mounted, center piloted.
The lug nuts are a two-piece assembly. When the tires are
being rotated or replaced, clean these lug nuts and add
two drops of oil at the interface between the lug nut/bolt
and the washer.
Do not oil wheel studs.
Inspect the wheel mounting surface prior to mounting
the tire and remove any corrosion or loose particles.
Tighten the lug nuts/bolts in a star pattern until each
nut/bolt has been tightened twice.
Wheel Mounting Surface
6
WHAT TO DO IN EMERGENCIES 687
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Jack Instructions (1500 Series)
WARNING!
Carefully follow these tire changing warnings to
help prevent personal injury or damage to your
vehicle:
•Always park on a firm, level surface as far from the
edge of the roadway as possible before raising the
vehicle.
•Turn on the Hazard Warning flasher.
•Block the wheel diagonally opposite the wheel to
be raised.
•Set the parking brake firmly and set an automatic
transmission in PARK; a manual transmission in
REVERSE.
•Never start or run the engine with the vehicle on a
jack.
(Continued)
WARNING!(Continued)
•Do not let anyone sit in the vehicle when it is on a
jack.
•Do not get under the vehicle when it 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.
•Only use the jack in the positions indicated and for
lifting this vehicle during a tire change.
•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.
6
WHAT TO DO IN EMERGENCIES 697
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each nut has been tightened twice. For the correct lug
nut torque refer to “Torque Specifications” in this
section. If in doubt about the correct tightness, have
them checked with a torque wrench by you authorized
dealer or 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.
7. Install the wheel center cap and remove the wheel
blocks. Do not install chrome or aluminum wheel
center caps on the spare wheel. This may result in cap
damage.
8. Lower the jack to its fully closed position. If the bottle
jack will not lower by turning the dial (thumbwheel)
by hand, it may be necessary to use the jack drive tube
in order to lower the jack. Stow the replaced tire, jack,
and tools as previously described.
9. Adjust the tire pressure when possible.
NOTE:Do not oil wheel studs. For chrome wheels, do
not substitute with chrome plated wheel nuts.
To Stow The Flat Or Spare
NOTE:Vehicles equipped with aluminum wheels can-
not be stored under the vehicle because the wheel
retainer will not fit through the wheel pilot hole. Secure
the flat tire in the bed of the truck.Have the flat tire
repaired or replaced immediately.
702 WHAT TO DO IN EMERGENCIES
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WARNING!
A loose tire thrown forward in a collision or hard
stop could injure the occupants in the vehicle. Have
the deflated (flat) tire repaired or replaced immedi-
ately.
1. Turn the wheel so that the valve stem is facing the
ground and toward the rear of the vehicle for conve-
nience in checking the spare tire inflation. Slide the
wheel retainer through the center of the wheel.
Reinstalling The Retainer6
WHAT TO DO IN EMERGENCIES 703
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WARNING!(Continued)
•Only use the jack in the positions indicated and for
lifting this vehicle during a tire change.
•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.
Jack Warning Label
Lug Wrench Adaptor Shown In Jack And Tools Assembly6
WHAT TO DO IN EMERGENCIES 717
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5. Remove the wheel nuts and pull the wheel off. On
single rear-wheel (SRW) trucks, install the spare wheel
and wheel nuts with the cone shaped end of the wheel
nuts toward the wheel. On 3500 dual rear-wheel
models (DRW) trucks, if the outer tire is being re-
placed then leave the inner wheel on the vehicle. If the
inner wheel is being replaced remove the outer wheel
and replace the inner wheel. The wheel nuts are a
two-piece assembly with a flat face. Lightly tighten the
wheel nuts. To avoid the risk of forcing the vehicle off
the jack, do not fully tighten the wheel nuts until the
vehicle has been lowered.
Rear Inner Wheel Proper Placement (Dual Rear Wheel
Equipped)
6
WHAT TO DO IN EMERGENCIES 721