1998 GMC SIERRA tires

You can shift from 2-WHEEL HIGH (2H) to 4-WHEEL
HIGH (4H) or from 4-WHEEL HIGH (4H) to
2-WHEEL HIGH (2H) while
the vehicle is moving.
Your front axle will engage faster
if you take your foot
off the accelerator for a few seconds after you shift. In
extremely cold weather, it may be necessary to stop or
slow the vehicle
to shift into 4-WHEEL HIGH (4H).
To
shift into or out of 4-WHEEL LOW (4L) or
NEUTRAL
(N):
1. Slow the vehicle to a roll, about 1 to 3 mph
(2
to 5 km/h) and shift an automatic transmission
into NEUTRAL
(N), or with a manual transmission,
press the clutch pedal.
2. Shift
the transfer case shift lever in one
continuous motion.
Don’t pause
in NEUTRAL (N) as you shift the
transfer case into 4-WHEEL LOW (4L), or your
gears
could clash.
Remember that driving
in 4-WHEEL HIGH (4H) or
4-WHEEL LOW (4L) may reduce
fuel economy. Also,
driving
in four-wheel drive on dry pavement could
cause your tires to wear faster and make your transfer
case harder
to shift and run noisier. When your headlamps
or parking lamps are on, rotate the
thumb wheel next
to the headlamp switch up to brighten
or down to dim your transfer case indicator light.
Electronic Transfer Case (If Equipped)
If your four-wheel-drive vehicle has the electronic
transfer case,
the transfer case switches are below and to
the left of the climate control system.
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The body takes about an hour to rid itself of the alcohol
in one drink. No amount of coffee or number of cold
showers will speed that up.
“I’ll be careful” isn’t the
right answer. What
if there’s an emergency, a need to
take sudden action, as when a child darts into the street?
A person with even a moderate BAC might not be able
to react quickly enough to avoid the collision.
There‘s something else about drinking and driving that
many people don’t know. Medical research shows that
alcohol
in a person’s system can make crash injuries
worse, especially injuries to the brain, spinal cord or
heart. This means that when anyone who has been
drinking
-- driver or passenger -- is in a crash, that
person’s chance of being killed or permanently disabled
is higher than if the person had not been drinking.
A CAUTION:
Drinking and then driving is very dangerous.
Your reflexes, perceptions, attentiveness and
judgment can be affected by even a small amount
of alcohol. You can have a serious
-- or even
fatal
-- collision if you drive after drinking.
Please don’t drink and drive or ride with
a driver
who has been drinking. Ride home in
a cab; or if
you’re with
a group, designate a driver who will
not drink.
Control of a Vehicle
You have three systems that make your vehicle go where
you want
it to go. They are the brakes, the steering and
the accelerator.
All three systems have to do their work
at the places where the tires meet
the road.
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Sometimes, as when you’re driving on snow or ice, it’s
easy to ask more of those control systems than the tires
and road can provide. That means you can lose control
of your vehicle.
Braking
Braking action involves perception time and reaction time.
First, you have to decide to push on the brake pedal.
That’s
perception time. Then you have to bring up your
foot and do it. That’s
reaction time.
Average reaction time is about 3/4 of a second. But
that’s only an average. It might be less with one driver
and as long as two or three seconds or more with
another. Age, physical condition, alertness, coordination
and eyesight all play a part.
So do alcohol, drugs and
frustration. But even in
3/4 of a second, a vehicle
moving at
60 mph (100 km/h) travels 66 feet (20 m).
That could be
a lot of distance in an emergency, so
keeping enough space between your vehicle and others
is important.
And, of course, actual stopping distances vary greatly
with the surface
of the road (whether it’s pavement or
gravel); the condition
of the road (wet, dry, icy); tire
tread; the condition of your brakes; the weight of the
vehicle and the’amount of brake force applied.
Avoid needless heavy braking. Some people drive in
spurts
-- heavy acceleration followed by heavy
braking
-- rather than keeping pace with traffic. This
is a mistake. Your brakes may not have time to cool
between hard stops. Your brakes will wear out much
faster if you do a lot of heavy braking. If you keep pace
with the traffic and allow realistic following distances,
you will eliminate a lot of unnecessary braking. That
means better braking and longer brake life.
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Speed Sensitive Steering
This system varies the amount of steering effort
proportionate
to your vehicle speed. Steering is easier at
lower speeds for maneuvering and parking ease.
As your
vehicle speed increases,
the steering effort also
increases.
At highway speeds, the amount of steering
effort is increased for vehicle control and stability.
Steering Tips
Driving on Curves
It’s important to take curves at a reasonable speed.
A lot of the “driver lost control” accidents mentioned on
the news happen on curves. Here’s why:
Experienced driver or beginner, each
of us is subject to
the same laws of physics when driving on curves. The
traction of the tires against the road surface makes
it
possible for the vehicle to change its path when you turn
the front wheels.
If there’s no traction, inertia will keep
the vehicle going
in the same direction. If you’ve ever
tried
to steer a vehicle on wet ice, you‘ll understand this.
The traction
you can get in a curve depends on the
condition of your tires and the road surface, the angle at which the curve
is banked, and your speed. While you’re in
a curve, speed is the one factor you can control. Suppose you’re
steering through a sharp curve.
Then you suddenly accelerate. Both control
systems
-- steering and acceleration -- have to do their
work where the tires meet the road. Adding the sudden
acceleration can demand too much
of those places. You
can lose control.
What should
you do if this ever happens? Ease up on the
accelerator pedal, steer the vehicle the way
you want it
to go, and slow down.
Speed
limit signs near curves warn that you should
adjust your speed.
Of course, the posted speeds are
based on good weather and road conditions. Under less
favorable conditions you’ll want to go slower.
If you need to reduce your speed as you approach a
curve, do
it before you enter the curve, while your front
wheels are straight ahead.
Try to adjust your speed
so you can “drive” through the
curve. Maintain a reasonable, steady speed. Wait to
accelerate
until you are out of the curve, and then
accelerate gently into the straightaway.
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Loss of Control
Let’s review what driving experts say about what
happens when the three control systems (brakes, steering
and acceleration) don’t have enough friction where
the
tires meet the road to do what the driver has asked.
In any emergency, don’t give up. Keep trying to steer and
constantly seek an escape route or area of less danger.
Skidding
In a skid, a driver can lose control of the vehicle. Defensive
drivers avoid most skids by taking reasonable care suited
to
existing conditions, and by not “overdriving” those
conditions. But skids are always possible.
The three types of skids correspond
to your vehicle’s
three control systems. In the braking skid, your wheels
aren’t rolling. In the steering or cornering skid,
too
much speed or steering in a curve causes tires to slip and
lose cornering force. And
in the acceleration skid, too
much throttle causes the driving wheels to spin.
A cornering skid and an acceleration skid are best
handled by easing your foot off the accelerator pedal. If
your vehicle starts
to slide, ease your foot off the
accelerator pedal and quickly steer the way you want the
vehicle
to go. If you start steering quickly enough, your
vehicle may straighten out. Always be ready for
a
second skid if it occurs.
Of course, traction
is reduced when water, snow, ice.
gravel or other material
is on the road. For safety, you’ll
want to slow down and adjust your driving to these
conditions.
It is important to slow down on slippery
surfaces because stopping distance will be longer and
vehicle control more limited.
While driving on a surface
with reduced traction, try
your best to avoid sudden steering, acceleration or
braking (including engine braking
by shifting to a lower
gear). Any sudden changes could cause the tires
to slide.
You may not realize the surface is slippery until your
vehicle is skidding. Learn to recognize warning clues
--
such as enough water, ice or packed snow on the road to
make
a “mirrored surface” -- and slow down when you
have any doubt.
Remember:
Any anti-lock brake system (ABS) helps
avoid only the braking skid.
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Environmental Concerns
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Cargo on the load floor piled higher man
the seatbacks can be thrown forward during a sudden stop. You or
your
passengers could be injured. Keep cargo
below the top of the seatbacks.
Unsecured cargo on the load floor can be
tossed about when driving over rough
terrain. You or your passengers can be
struck
by flying objects. Secure the
cargo properly.
Heavy loads on the roof raise the vehicle's
center of gravity, making it more likely to
roll over. You can be seriously or fatally
injured if the vehicle rolls over. Put heavy
loads inside the cargo area, not on the roof.
Keep cargo in the cargo area as
far forward
and low as possible.
You'll find other important information in this manual.
See "Vehicle Loading," "Luggage Carrier" and "Tires"
in the Index. Off-road
driving can provide wholesome and satisfying
recreation. However,
it also raises environmental
concerns.
GM recognizes these concerns and urges
evesy off-roader to follow these basic rules for
protecting the environment:
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Always use established trails, roads and areas that
have been specially set aside
for public off-road
recreational driving; obey all posted regulations.
Avoid any driving practice that could damage the
environment
-- shrubs, flowers, trees, grasses -- or
disturb wildlife (this includes wheel-spinning,
breaking down trees or unnecessary driving through
streams or over soft ground
j.
Always carry a litter bag . . . make sure all refuse is
removed from any campsite before leaving.
Take extreme care
with open fires (where permitted),
camp stoves and lanterns.
Never park your vehicle over dry grass or other
combustible materials that could catch fire from the
heat of the vehicle's exhaust system.
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Q.' Am I likely to stall when going downhill?
A: It's much more likely to happen going uphill. But if
it happens going downhill, here's what to do.
Stop your vehicle by applying the regular brakes.
Apply the parking brake.
Shift to PARK (Pj (or to NEUTRAL (Nj with the
manual transmission) and, while still braking, restart
the engine.
Shift back to a low gear, release the parking brake,
and drive straight down.
0 If the engine won't start, get out and get help.
Driving Across an Incline
Sooner or later, an off-road trail will probably go across
the incline of a
hill. If this happens, you have to decide
whether to try to drive across the incline. Here are some
things to consider:
A hill that can be driven straight up or down may be
too steep to drive across. When you go straight up or
down a
hill, the length of the wheel base (the
distance from the front wheels to the rear wheels)
reduces the likelihood the vehicle will tumble end over end.
But when
you drive across an incline, the
much more narrow track width (the distance between
the left and right wheels) may not prevent the vehicle
from tilting and rolling over.
Also, driving across an
incline puts more weight on the downhill wheels.
This could cause
a downhill slide or a rollover.
Surface conditions can be a problem when you drive
across
a hill. Loose gravel, muddy spots, or even wet
grass can cause your tires to slip sideways, downhill.
If the vehicle slips sideways, it can hit something
that will trip
it (a rock, a rut, etc.) and roll over.
Hidden obstacles can make the steepness of the
incline even worse.
If you drive across a rock with
the uphill wheels, or
if the downhill wheels drop into
a rut or depression, your vehicle can tilt even more.
For reasons like these, you need to decide carefully
whether to try to drive across an incline. Just because
the trail goes across the incline doesn't mean you
have to drive it. The last vehicle to try
it might have
rolled over.
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I-
I A CAUTION:
-
~ Getting out on the downhill (low) side of a vehicle
~ stopped across an incline is dangerous. If the
vehicle
rolls over, you could be crushed or killed.
Always get out on the uphill (high) side of the
~ vehicle and stay well clear of the rollover path.
Driving in Mud, Sand, Snow or Ice
When you drive in mud, snow or sand, your wheels
won’t get good traction. You can’t accelerate
as
quickly, turning is more difficult, and you’ll need
longer braking distances.
It‘s best to use a low gear when you’re
in mud -- the
deeper the mud, the lower the gear.
In really deep mud,
the idea
is to keep your vehicle moving so you don’t
get stuck.
When you drive on sand, you’ll sense
a change in wheel
traction. But
it will depend upon how loosely packed the
sand is. On loosely packed sand (as on beaches or sand
dunes) your tires will tend to sink into the sand. This has
an
effect on steering, accelerating and braking. You may
want to reduce the air pressure in your tires slightly
when driving on sand. This will improve traction.
Hard packed snow and ice offer the worst tire traction.
On these surfaces, it’s very easy to lose control. On wet
ice, for example, the traction is
so poor that you will
have difficulty accelerating. And
if you do get moving,
poor steering
and difficult braking can cause you to slide
out of control.
r A CAUTION:
Driving on frozen lakes, ponds or rivers can be
dangerous. Underwater springs, currents under
the ice, or sudden thaws can weaken the ice. Your
vehicle could fall through the ice and you and
your passengers could drown. Drive your vehicle
on safe surfaces only.
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