Tire pressure should be checked and adjusted as well as
inspected for signs of tire wear or visible damage, at least
once a month. Use a good quality pocket-type gauge to
check tire pressure. Do not make a visual judgement
when determining proper inflation. Radial tires may look
properly inflated even when they are under-inflated.
CAUTION!
After inspecting or adjusting the tire pressure, al-
ways reinstall the valve stem cap. This will prevent
moisture and dirt from entering the valve stem,
which could damage the Tire Pressure Monitoring
Sensor.
Inflation pressures specified on the placard are always
“cold tire inflation pressure.” Cold tire inflation pressure
is defined as the tire pressure after the vehicle has not
been driven for at least three hours, or driven less than
1 mile (1.6 km) after a three-hour period. The cold tire
inflation pressure must not exceed the maximum infla-
tion pressure molded into the tire side wall.
Check tire pressures more often if subject to a wide range
of outdoor temperatures, as tire pressures vary with
temperature changes.
Tire Placard Location (Four-Door Models)
344 STARTING AND OPERATING
Radial-Ply Tires
WARNING!
Combining radial ply tires with other types of tires
on your vehicle will cause your vehicle to handle
poorly. The instability could cause an accident. Al-
ways use radial tires in sets of four. Never combine
them with other types of tires.
Cuts and punctures in radial tires are repairable only in
the tread area because of sidewall flexing. Consult your
authorized dealer for radial tire repairs.
Tire Spinning
When stuck in mud, sand, snow, or ice conditions, do not
spin your vehicle’s wheels above 35 mph (55 km/h).
WARNING!
Fast spinning tires can be dangerous. Forces gener-
ated by excessive wheel speeds may cause tire dam-
age or failure. A tire could explode and injure some-
one. Do not spin your vehicle’s wheels faster than
35 mph (55 km/h) when you are stuck, and do not let
anyone near a spinning wheel no matter what the
speed.
346 STARTING AND OPERATING
TIRE CHAINS
Install chains on rear tires only. Tire chains may be
installed on all models except the Sahara and Rubicon.
Follow these recommendations to guard against damage
and excessive tire and chain wear:
•Use chains on P225/75R16 tires only. P255/75R17,
P255/70R18, and LT255/75R17 tires do not provide
adequate clearance.
•Use SAE class “S” tire chains or traction devices only.
•Chains must be the proper size for the vehicle, as
recommended by the chain manufacturer.
•Follow tire chain manufacturer’s instructions for
mounting chains.
•Install chains snugly and tighten after 0.6 mile (1 km)
of driving.
•Do notexceed 30 mph (48 km/h).
•Drive cautiously, avoiding large bumps, potholes and
extreme driving maneuvers.
TIRE ROTATION RECOMMENDATIONS
Tires on the front and rear axles of vehicles operate at
different loads and perform different steering, handling,
and braking functions. For these reasons, they wear at
unequal rates, and develop irregular wear patterns.
These effects can be reduced by timely rotation of tires.
The benefits of rotation are especially worthwhile with
aggressive tread designs such as those on On/Off Road
type tires. Rotation will increase tread life, help to main-
tain mud, snow, and wet traction levels, and contribute to
a smooth, quiet ride.
Refer to the “Maintenance Schedule” in Section 8 for the
proper maintenance intervals. More frequent rotation is
permissible if desired. The reasons for any rapid or
unusual wear should be corrected prior to rotation being
performed.
350 STARTING AND OPERATING
off until the tire pressure is at or above recommended
cold placard pressure. Once the “Tire Pressure Monitor-
ing Telltale Light” has been illuminated, the tire pressure
must be increased to the recommended cold placard
pressure in order for the “Tire Pressure Monitoring
Telltale Light” to be turned OFF. The system will auto-
matically update and the “Tire Pressure Monitoring
Telltale Light” will extinguish once the updated tire
pressures have been received. The vehicle may need to be
driven for up to 20 minutes above 15 mph (25 km/h) to
receive this information.
For example, your vehicle may have a recommended
cold (parked for more than three hours) air pressure of
35 psi (241 kPa). If the ambient temperature is 68°F (20°C)
and the measured tire pressure is 30 psi (207 kPa), a
temperature drop to 20°F (-7°C) will decrease the tire
pressure to approximately 26 psi (179 kPa). This tire
pressure is sufficiently low enough to turn ON the “Tire
Pressure Monitoring Telltale Light.” Driving the vehiclemay cause the tire pressure to rise to approximately
30 psi (207 kPa), but the “Tire Pressure Monitoring
Telltale Light” will still be ON. In this situation, the “Tire
Pressure Monitoring Telltale Light” will turn OFF only
after the tires have been inflated to the vehicle’s recom-
mended cold placard pressure value.
CAUTION!
•The TPMS has been optimized for the original
equipment tires and wheels. The TPMS pressures
have been established for the tire size equipped
on your vehicle. Undesirable system operation or
sensor damage may result when using replace-
ment equipment that is not of the same size, type,
and/or style. Aftermarket wheels can cause sensor
damage. Do not use aftermarket tire sealants or
balance beads if your vehicle is equipped with a
TPMS, as damage to the sensors may result.
(Continued)
352 STARTING AND OPERATING
The entire vehicle should first be weighed on a commer-
cial scale to ensure that the GVWR has not been ex-
ceeded. 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 affect
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.
TRAILER TOWING
In this section, you will find safety tips and information
on limits to the type of towing you can reasonably do
with your vehicle. Before towing a trailer, carefully
review this information to tow your load as efficiently
and safely as possible.
To maintain warranty coverage, follow the requirements
and recommendations in this Owner’s Manual concern-
ing vehicles used for trailer towing.
5
STARTING AND OPERATING 365
NOTE:Remember that everything put into or on the
trailer adds to the load on your vehicle. Also, additional
factory-installed options, or authorized dealer-installed
options, must be considered as part of the total load on
your vehicle. Refer to the Tire and Loading Information
placard in the “Tire Safety Information” section of this
manual for the maximum combined weight of occupants
and cargo for your vehicle.
Towing Requirements
To promote proper break-in of your new vehicle drive-
train components, the following guidelines are recom-
mended:
NOTE: Trailer towing requires special rear axle lubri-
cant. Refer to “Fluids, Lubricants, and Genuine Parts” in
Section 7 for the correct fluid type.
CAUTION!
•Avoid towing a trailer for the first 500 miles
(805 km) of vehicle operation. Doing so may dam-
age your vehicle.
WARNING!
Improper towing can lead to an injury accident.
Follow these guidelines to make your trailer towing
as safe as possible:
•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 an accident.
(Continued)
376 STARTING AND OPERATING
wheel nut tightness is 95 ft lbs (130 N·m). If in doubt
about the correct tightness, have them checked with a
torque wrench by your authorized dealer or at a service
station.
10. Remove the jack assembly and wheel blocks.
WARNING!
A loose tire or jack, thrown forward in a collision or
hard stop, could endanger the occupants of the ve-
hicle. Always stow the jack parts and the spare tire in
the places provided.
11. Secure the tire, jack, and tools in their proper
locations.
JUMP-STARTING
If the vehicle has a discharged battery, booster cables may
be used to obtain a start from a booster battery or the
battery in another vehicle. This type of start can be dangerous if done improperly, so follow this procedure
carefully.
WARNING!
•Battery fluid is a corrosive acid solution; do not
allow battery fluid to contact eyes, skin or cloth-
ing. Do not lean over a battery when attaching
clamps or allow the clamps to touch each other. If
acid splashes in your eyes or on skin, flush the
contaminated area immediately with large quanti-
ties of water.
•A battery generates hydrogen gas which is flam-
mable and explosive. Keep flames or sparks away
from the vent holes.
•Do not use a booster battery or any other booster
source that has a greater than 12 Volt system (i.e.,
do not use a 24 Volt power source).
394 WHAT TO DO IN EMERGENCIES
Selection of Lubricant
Use only manufacturer’s recommended fluid. Refer to
“Fluids, Lubricants, and Genuine Parts” in this section
for the correct fluid type.
Maintenance After Off-Road Driving
After extended operation in mud, sand or water, or
similar dirty conditions, have your brake drums, brake
linings, and axle joints inspected and cleaned as soon as
possible. This will prevent any abrasive material from
causing excessive wear or unpredictable braking action.
Following off-road usage, completely inspect the under-
body of your vehicle. Check the tires, body structure,
steering, suspension and exhaust system for damage.
Check the threaded fasteners for looseness, particularly
on the chassis, drivetrain components, steering and sus-
pension. Retighten, if required, to torque values specified
in the Service Manual. Also check for accumulations of
vegetation or brush that could become a fire hazard, orconceal damage to fuel lines, brake hoses, axle pinion
seals, and propeller shafts. Check the air conditioning
drain tube on the lower dash wall in the engine compart-
ment for mud or debris, and clean as required. A plugged
tube will adversely affect air conditioning performance.CAUTION!
Under frequent heavy-duty driving conditions,
change all lubricants, and lubricate body compo-
nents more often than in normal service to prevent
excessive wear.
Appearance Care and Protection from Corrosion
Protection of Body and Paint from Corrosion
Vehicle body care requirements vary according to geo-
graphic locations and usage. Chemicals that make roads
passable in snow and ice, and those that are sprayed on
trees and road surfaces during other seasons, are highly
428 MAINTAINING YOUR VEHICLE