GMC SIERRA 1998 Owners Manual

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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Off-Road Driving with Your
Four-Wheel-Drive
Vehicle
This off-road guide is for vehicles that have
four-wheel drive.
Also, see “Anti-Lock Brakes“
in the Index.
If your vehicle doesn’t have four-wheel drive, you
shouldn’t drive off-road unless you’re on a level,
solid surface.
Off-road driving can be great fun. But
it does have some
definite hazards. The greatest of these is the terrain itself.
“Off-roading” means you’ve left
the great North
American road system behind. Traffic lanes aren’t
marked. Curves aren’t banked. There are
no road signs.
Surfaces can be slippery, rough, uphill or downhill.
In
short, you’ve gone right back to nature.
Off-road driving involves some new skills. And that’s
why it’s very important that you read this guide. You’ll
find many driving tips and suggestions. These
will help
make your off-road driving safer and more enjoyable.
Before You Go Off-Roading
There are some things to do before you go out. For
example, be
sure to have all necessary maintenance and
service work done. Check
to make sure all underbody
shields
(if so equipped) are properly attached. Be sure
you read
all the information about your
four-wheel-drive vehicle
in this manual. Is there enough
firel‘?
Is the spare tire fully inflated? Are the fluid levels
up where
they should be‘? What are the local laws that
apply to off-roading where you’ll be driving?
If you
don’t know, you should check
with law enforcement
people
in the area. Will you be on someone’s private
land?
If so, be sure to get the necessary permission.
Loading Your Vehicle for Off-Road Driving
There are some important things to remember about
how to load your vehicle.
0 The heaviest things should be on the load floor and
forward of your rear axle. Put heavier items
as far
forward
as you can.
Be sure the load is secured properly, so driving on
the off-road terrain doesn’t toss things around.
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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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Traveling to Remote Areas
It makes sense to plan your trip, especially when going
to a remote area. Know
the terrain and plan your route.
You are much less likely to get bad surprises. Get
accurate maps of trails and terrain. Try to learn of any
blocked or closed roads. Controlling your vehicle
is
the key to successful
off-road driving. One of the best ways
to control your
vehicle
is to control your speed. Here are some things to
keep
in mind. At higher speeds:
0 you approach things faster and you have less time to
scan the terrain for obstacles.
It’s also
a good idea to travel with at least one other
vehicle. If something happens to one of them, the other
can help quickly. you have less time to react.
0 you have more vehicle bounce when you drive
over obstacles.
Does your vehicle have a winch?
If so, be sure to read
the winch instructions. In a remote area, a winch can be
handy
if you get stuck. But you’ll want to know how to
use
it properly.
Getting Familiar with Off-Road Driving
It’s a good idea to practice in an area that’s safe and
close to home before you
go into the wilderness.
Off-road driving does require some new and different
driving skills. Here’s what we mean.
Tune your senses to different kinds of signals. Your
eyes, for example, need to constantly sweep the terrain
for unexpected obstacles. Your ears need to listen for
unusual tire or engine sounds. With your arms, hands,
feet and body, you’ll need
to respond to vibrations and
vehicle bounce.
0 you’ll need more distance for braking, especially
since you’re on an unpaved surface.
When you’re driving off-road, bouncing and
quick changes in direction can easily throw you
out of position. This could cause you to lose
control and crash.
So, whether you’re driving on
or
off the road, you and your passengers should
wear safety belts.
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Scanning the Terrain
Off-road driving can take you over many different kinds
of terrain. You need to
be familiar with the terrain and its
many different features. Here are some things to consider.
Su$ace Conditions. Off-roading can take you over
hard-packed dirt, gravel, rocks, grass, sand, mud, snow or
ice. Each
of these surfaces affects the steering, acceleration
and braking of your vehicle in different ways. Depending
upon the kind of surface
you are on, you may experience
slipping, sliding, wheel spinning, delayed acceleration,
poor traction and longer braking distances.
Su$ace Obstacles. Unseen or hidden obstacles can be
hazardous. A rock, log, hole, rut or bump can startle you if
you’re not prepared for them. Often these obstacles are
hidden by grass, bushes, snow or even the
rise and fall of
the terrain itself. Here are some things to consider:
Is the path ahead clear?
Will the surface texture change abruptly up ahead?
Does the travel take you uphill or downhill? (There’s
more discussion of these subjects later.)
Will you have to stop suddenly or change
direction quickly? When
you drive over obstacles or
rough terrain, keep a
firm grip on the steering wheel. Ruts, troughs or
other
surface features can jerk the wheel out of your hands if
you’re not prepared.
When you drive over bumps, rocks, or other obstacles,
your wheels can leave the ground. If this happens, even
with
one or two wheels, you can’t control the vehicle as
well or at all.
Because
you will be on an unpaved surface, it’s
especially important to avoid sudden acceleration,
sudden turns or sudden braking.
In a way, off-road driving requires a different kind of
alertness from driving
on paved roads and highways.
There are
no road signs, posted speed limits or signal
lights. You have to use your own good judgment about
what is safe and what isn’t.
Drinking and driving can be very dangerous on any
road. And this is certainly true for off-road driving. At
the very time you need special alertness and driving
skills, your reflexes, perceptions and judgment can be
affected by even a small amount
of alcohol. You could
have a serious
-- or even fatal -- accident if you drink
and drive or ride with a driver who has been drinking.
See “Drunken Driving’’ in the Index.
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Driving on Off-Road Hills
Off-road driving often takes you up, down or across a
hill. Driving safely on hills requires good judgment and
an understanding
of what your vehicle can and can‘t do.
There are some hills that simply can’t be driven, no
matter how well built the vehicle.
I a CAUTION:
Many hills are simply too steep for any vehicle. If
you drive up them, you will stall. If you drive
1 down them, you can’t control your speed. If you
drive across them,
you will roll over. You could be
seriously injured or killed. If
you have any doubt
about the steepness, don’t drive the hill.
Approaching a Hill
When you approach a hill, you need to decide if it’s one
of those hills that’s just too steep
to climb, descend or
cross. Steepness can be hard tojudge. On a very small
hill, for example, there may be a smooth, constant
incline with only
a small change in elevation where you
can easily see all the way
to the top. On a large hill, the incline
may get steeper as you near the top, but
you may
not see this because the crest
of the hill is hidden by
bushes, grass
or shrubs.
Here are some other things to consider as you approach
a
hill.
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Is there a constant incline, or does the hill get sharply
steeper
in places‘?
Is there good traction on the hillside, or will the
surface cause tire slipping‘?
Is there a straight path up or down the hill SO you
won’t have to make turning maneuvers?
Are there obstructions on the
hill that can block your
path (boulders, trees, logs or ruts)?
What’s beyond the
hill? Is there a cliff, an
embankment,
a drop-off, a fence? Get out and
walk the
hill if you don’t know. It’s the smart way to
find out.
Is the hill simply too rough‘? Steep hills often have
ruts, gullies, troughs and exposed rocks because they
are more susceptible to the effects of erosion.
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Driving Uphill
Once you decide you can safely drive up the hill, you
need to take some special steps.
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Use a low gear and get a firm grip on the
steering wheel.
Get a smooth start
up the hill and try to maintain
your speed. Don’t
use more power than you need,
because you don’t want your wheels to start spinning
or sliding.
Try to drive straight up the
hill if at all possible. If
the path twists and turns, you might want to find
another route.
l A C * UYON:
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Ease up on your speed as you approach the top of
the hill.
Attach a flag to the vehicle to make you more visible
to approaching traffic on trails or hills.
Sound the horn as you approach the top
of the hill to
let opposing traffic know you’re there.
Use your headlamps even during the day. They make
you more visible to oncoming traffic.
Turning or driving across steep hills can be
dangerous. You could lose traction, slide
sideways, and possibly roll over. You could be
seriously injured or killed. When driving up hills,
always try to go straight up.
1 A CAUTION:
Driving to the top (crest) of a hill at full speed can
cause an accident. There could be a drop-off,
embankment, cliff, or even another vehicle. You
could be seriously injured or killed.
As you near
the top of a hill, slow down and stay alert.
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What should I do if my vehicle stalls, or is about
to stall, and I can’t make it up the hill?
A: If this happens, there are some things you should
do, and there
are some things you must not do.
First, here’s what you
should do:
0 Push the brake pedal to stop the vehicle and keep it
from rolling backwards.
Also, apply the parking brake.
0 If your engine is still running, shift the transmission
to REVERSE (R), release the parking brake, and
slowly back down the hill in REVERSE (R).
0 If your engine has stopped running, you’ll need to
restart
it. With the brake pedal depressed and the
parking brake still applied, shift the transmission to
PARK
(P) (or, shift to NEUTRAL (N) if your
vehicle has a manual transmission) and restart the
engine. Then, shift to REVERSE (R), release the
parking brake, and slowly back down the hill as
straight as possible in REVERSE (R).
0 As you are backing down the hill, put your left hand
on the steering wheel at the 12 o’clock position. This
way, you’ll be able to tell if your wheels are straight
and maneuver as you back down. It’s best that you back down
the hill with your wheels straight rather
than in the left or right direction. Turning the wheel
too far to the left or right will increase the possibility
of a rollover.
Here are some things you
must not do if you stall, or are
about to stall, when going up a hill.
0 Never attempt to prevent a stall by shifting into
NEUTRAL (N) (or depressing the clutch, if you
have a manual transmission) to “rev-up” the engine
and regain forward momentum. This won’t work.
Your vehicle will roll backwards very quickly and
you could
go out of control.
Instead, apply the regular brake to stop the vehicle.
Then apply the parking brake. Shift to
REVERSE (R), release the parking brake, and slowly back straight down.
Never attempt to turn around if you are about to stall
when going up a hill. If the hill is steep enough
to
stall your vehicle, it’s steep enough to cause you to
roll over if
you turn around. If you can’t make it up
the hill,
you must back straight down the hill.
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@ Suppose, after stalling, I try to back down the
hill and decide
I just can’t do it. What should
I do?
A: Set the parking brake, put your transmission in
PARK (P) (or the manual transmission in
FIRST (1)) and turn off the engine. Leave the
vehicle
and go get some help. Exit on the uphill
side and stay clear of
the path the vehicle would
take if it rolled downhill. Do not shift the transfer
case
to NEUTRAL (N) when you leave the vehicle.
Leave
it in some gear. Shifting the transfer case to NEUTRAL
(N) can
cause your vehicle to roll even if the transmission
is in PARK
(P) (or, if you have the manual
transmission, even if you’re in gear). This is
because the NEUTRAL
(N) position on the
transfer case overrides the transmission.
You or
someone else could be injured.
If you are going to
leave your vehicle, set the parking brake and
shift the transmission to PARK
(P) (or, put your
manual transmission in FIRST
(1)). But do not
shift the transfer case to the NEUTRAL (N)
position. Leave the transfer case in the
2 Wheel,
4 High or 4 Low position.
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Driving Downhill
When off-roading takes you downhill, you’ll want to
consider
a number of things:
How steep is the downhill? Will I be able to maintain
vehicle control?
What’s the surface like? Smooth‘? Rough‘? Slippery?
Hard-packed dirt? Gravel?
Are there hidden surfxe obstacles’? Ruts? Logs?
Boulders?
What’s at the bottom of the hill‘? Is there a hidden
creek bank or even
a river bottom with large rocks‘?
If you decide you can go down a hill safely, then try to
keep your vehicle headed straight down, and use a low
gear. This way, engine drag can help your brakes and
they won’t have to do all the work. Descend slowly,
keeping your vehicle under control at all times.
Heavy braking when going down a hill can cause
your brakes to overheat and fade. This could cause
loss of control and a serious accident. Apply the
brakes lightly when descending a hill and use a
low
gear to keep vehicle speed under control.
Are there some things
I should not do when
driving down a hill?
A: Yes! These are important because if you
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ignore them you could lose control and have a
serious accident.
When driving downhill, avoid turns that take you
across the incline of the
hill. A hill that’s not too
steep to drive down may be too steep to drive across.
You could
roll over if you don’t drive straight down.
Never
go downhill with the transmission in
NEUTRAL (N), or with the clutch pedal depressed
in a manual shift. This is called “free-wheeling.”
Your brakes
will have to do all the work and could
overheat
and fade.
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