Page 370 of 700

Hill Climbing
Hill climbing requires good judgment and a good under-
standing of your abilities and your vehicle’s limitations.
Hills can cause serious problems. Some are just too steep to
climb and should not be attempted. You should always feel
confident with the vehicle and your abilities. You should
always climb hills straight up and down. Never attempt to
climb a hill on an angle.
•Before Climbing A Steep Hill – As you approach a hill
consider its grade or steepness. Determine if it is too
steep. Look to see what the traction is on the hill side
trail. Is the trail straight up and down? What is on top
and the other side? Are there ruts, rocks, branches or
other obstacles on the path? Can you safely recover the
vehicle if something goes wrong? If everything looks
good and you feel confident, then change transmission
into a lower gear, shift the transfer case into 4LO (Low)
and proceed with caution. You should use first gear and
4LO (Low Range) for very steep hills.
• Driving Up Hill – Once you have determined your
ability to proceed and have shifted into the appropriate
gear, line your vehicle up for the straightest possible run.
Accelerate with an easy constant throttle and apply
more power as you start up the hill. Do not race forward into a steep grade, the abrupt change of grade could
cause you to lose control. If the front end begins to
bounce, ease off the throttle slightly to bring all four tires
back on the ground. As you approach the crest of the hill
ease off the throttle and slowly proceed over the top. If
the wheels start to slip as you approach the crest of a hill,
ease off the accelerator and maintain headway by turn-
ing the steering wheel no more than a ¼ turn quickly
back and forth. This will provide a fresh
biteinto the
surface and will usually provide enough traction to
complete the climb. If you do not make it to the top,
place the vehicle in REVERSE and back straight down
the grade using engine resistance along with the vehicle
brakes.
WARNING!
Never attempt to climb a hill at an angle or turn around
on a steep grade. Driving across an incline increases
the risk of a roll over, which may result in severe injury
or death.
• Driving Down Hill – Before driving down a steep hill
you need to determine if it is too steep for a safe descent.
What is the surface traction? Is the grade too steep to
maintain a slow controlled descent? Are there obstacles?
368 STARTING AND OPERATING
Page 571 of 700

Fuel Economy
Underinflated tires will increase tire rolling resistance
resulting in higher fuel consumption.
Tread Wear
Improper cold tire inflation pressures can cause abnormal
wear patterns and reduced tread life, resulting in the need
for earlier tire replacement.
Ride Comfort And Vehicle Stability
Proper tire inflation contributes to a comfortable ride.
Over-inflation produces a jarring and uncomfortable ride.
Tire Inflation Pressures
The proper cold tire inflation pressure is listed on the
driver’s side B-Pillar or rear edge of the driver’s side door.
At least once a month:
•Check and adjust tire pressure with a good quality
pocket-type pressure gauge. Do not make a visual
judgement when determining proper inflation. Tires
may look properly inflated even when they are under-
inflated.
• Inspect tires for signs of tire wear or visible damage.
CAUTION!
After inspecting or adjusting the tire pressure, always
reinstall the valve stem cap. This will prevent moisture
and dirt from entering the valve stem, which could
damage the valve stem.
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 sitting for a minimum of three hours. The
cold tire inflation pressure must not exceed the maximum
inflation pressure molded into the tire sidewall.
Check tire pressures more often if subject to a wide range
of outdoor temperatures, as tire pressures vary with tem-
perature changes.
Tire pressures change by approximately 1 psi (7 kPa) per
12°F (7°C) of air temperature change. Keep this in mind
when checking tire pressure inside a garage, especially in
the Winter.
Example: If garage temperature = 68°F (20°C) and the
outside temperature = 32°F (0°C) then the cold tire inflation
8
SERVICING AND MAINTENANCE 569
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CAUTION!(Continued)
the truck. For example, if the spare is used to replace
an outer rear tire it will have to be remounted on the
rim so that the wheel is dished inward. That way the
tread design of asymmetrical tires and the white
writing of the OWL tires will maintain proper posi-
tion.
DEPARTMENT OF TRANSPORTATION UNIFORM
TIRE QUALITY GRADES
The following tire grading categories were established
by the National Highway Traffic Safety Administration.
The specific grade rating assigned by the tire’s manu-
facturer in each category is shown on the sidewall of the
tires on your vehicle.
All passenger vehicle tires must conform to Federal
safety requirements in addition to these grades.
Treadwear
The Treadwear grade is a comparative rating, based on
the wear rate of the tire when tested under controlled
conditions on a specified government test course. For
example, a tire graded 150 would wear one and one-half
times as well on the government course as a tire graded 100. The relative performance of tires depends upon the
actual conditions of their use, however, and may depart
significantly from the norm due to variations in driving
habits, service practices, and differences in road charac-
teristics and climate.
Traction Grades
The Traction grades, from highest to lowest, are AA, A, B,
and C. These grades represent the tire’s ability to stop on
wet pavement, as measured under controlled conditions on
specified government test surfaces of asphalt and concrete.
A tire marked C may have poor traction performance.
WARNING!
The traction grade assigned to this tire is based on
straight-ahead braking traction tests, and does not
include acceleration, cornering, hydroplaning, or
peak traction characteristics.
Temperature Grades
The Temperature grades are A (the highest), B, and C,
representing the tire’s resistance to the generation of
heat and its ability to dissipate heat, when tested under
controlled conditions on a specified indoor laboratory
test wheel. 8
SERVICING AND MAINTENANCE 583