wheel GMC SIERRA 1993 Owner's Guide

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: the rear wheel anti-lock braking system (RWAL) helps\
avoid only
a rear braking skid. In a braking skid (where the front wheels are no longer
rolling), release enough pressure on the brakes to get the front wheels rolling
again. This restores steering control. Push the brake pedal dow\
n steadily
when you have to stop suddenly.
As long as the front wheels are rolling, you
will have steering control. Steer the way you want to go.
Off-Road Driving with Your FourcWheel
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, so\
lid surface.
Off-road driving can be great fun. But it does have some defi\
nite 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 a\
re 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. Be sure \
you read all
the information about your four-wheel drive vehicle in this manual.
Is there
enough fuel?
Is the spare tire fully inflated? Are the fluid levels up where
they should be? What are the local laws that apply to off-roa\
ding 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.
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Tune your senses to different kinds of signals. -Your eyes, for example, meed
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.
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:
e you approach things fastar and you have less time to scan the terrain
for obstacles.
you have less time
to react. ‘I , ’C _. ’.
you have more vehicle bounce when you drive over obstacles.
you’ll need more distance for braking, especially since you’\
re on an unpaved surface.
CAUTION
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.
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.
Surface Conditions
Off-roading can ta.ke you. over hard-packed dirt, gravel, rocks,\
grass, sand, mud, snow or ice. Each of these sutfaces 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\
.
Surface 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?
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Your Driving and the Road
Does the travel take you uphill or downhill? (There’s more \
discussion of
Will you have to stop suddenly or change direction quickly? these subjects later.)
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 whe\
els can leave
the ground.
If this happens, even with one or two wheels, you can’t contro\
l
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 spee\
d 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 I
1 certainly true for off-road driving. At the very time you need special
alertness and driving skills, your reflexes, perceptions and jud\
gment
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.)
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.
A, Many hills are simply too steep for any vehicle. If you drive up them,
- IOU will stall. If you drive 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.
I I
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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 to judge.
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.
Is there a constant incline, or does the hill get sharply steeper in
Is there good traction on the hillside, or will the surface cause tire
Is there a straight path up or down the hill so you won’t have to make
0 Are there obstructions on the hill than can block your path (boulders,
What’s beyond the hill? Is there a cliff, an embankment, a drop-off, a
places?
slipping?
turning maneuvers?
trees, logs
or ruts)?
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 eff\
ects
of
erosion.
Driving Uphill
Once you decide you can safely drive up the hill, you need to take some
special steps.
Use a lower 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 wheel\
s to start
spinning
or sliding.
turns, you might want
to find another route.
Try to drive straight up the hill if at all possible. If the path twists and
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Your Driving and the Road
A 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
I 'I' ?d. When driving up hills, always try to go
I straight up.
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 hill to let opposing traffic
know you're there.
Use your headlights even during the day. They make you more visible to
oncoming traffic.
I A Driving to the top (crest) of a hill at full speed can muse an
accident.
There could be a drop-off, embankment, cliff, or even
another vehicle. You buld be seriously injured or killed. .As you near
the
top of a hill, slow down and stay alert. I
Q: 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
0
0
0
Push the brake pedal to stop the vehicle and keep it from rolling
backwards.
Also, apply the parking brake.
If your engine is still running, shift the transmission into reverse, release
the parking brake, and slowly back down the hill in reverse.
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
P (Park) (or, shift to N (Neutral) if your vehicle has a
manual transmission) and restart the engine. Then, shift to Reverse,
release the parking brake, and slowly back down the hill in reverse.
As you are backing down the hill, put your left hand on the ste\
ering
wheel at the
12 o'clock position. This way, you'll be able to tell if your
wheels are straight or turned to the left or right as you back down.
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Here are some things you must not do if you stall, or are about to stall,
when going up a hill.
Never attempt to prevent a stall by shifting into N (Neutral) (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 into reverse, release the parking brake, and slowl\
y back 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 down the hill.
Q: 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 P (Park) (or the manual
transmission in first gear), 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 N (Neutral)
when you leave the vehicle. Leave it in some gear.
Shifting the transfer case to
N (Neutral) can cause your vehicle to
roll even
if the transmission is in P (Park) (or, if you have the
manual transmission, even
if you’re in gear). This is because the N
(Neutral) position on the transfer case overrides the transmis\
sion. If
you are going to leave your vehicle, set the parking brake and shi”
the transmission to
P (Park) (or, put your manual transmission in f
gear). But do not shift the transfer case to the N (Neutral) positior
Leave the transfer case in the
2 Wheel, 4 High or 4 Low position.
1
Lriving 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? Grave
I?
Are there hidden surface 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?
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Your Driving and the Road
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 dr\
ag can help
your brakes and they won’t have to do
all the work. Descend slowly, keeping
your vehicle under control at all times.
CAUTION
A 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.
Q: Are there some things I should not do when driving down a hili?
A: Yes! These are important because if you ignore them you could lose
control and have a serious accident.
When driving downhill, avoid turns that take you across the in\
cline 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 N (Neutral), or with the clutch
pedal depressed in a manual shift. This is called “free-whee\
ling,” Your
brakes will have
to do all the work and could overheat and fade.
Avoid braking so hard that you lock the wheels when going downhill. If
your front wheels are locked, you can’t steer your vehicle. \
If your wheels
lock up during downhill braking, you may feel the vehicle star\
ting to slide
sideways.
To regain your direction, just ease off the brakes and steer to
keep the front of the vehicle pointing straight downhill.
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 pa\
rking
brake.
Shift to P (Park) (or to Neutral 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.
If the engine won’t start, get out and get help.
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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:
0
For
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.
reasons like these, you need to decide carefully whether to try to drive
across an incline. Just because the trail goes across the incl\
ine doesn’t mean
you have to drive it. The last vehicle to try
it might have rolled over.
CAUTIP!
4 Driving across an incline that’s too steep will make your v\
ehicle roll
over. You could be seriously injured or killed. If you have any doubt
about the steepness
of the incline, don’t drive across it. Find another
route instead.
Q: What if I’m driving across an incline that’s not too steep, but I hit
some
loose gravel and start to slide downhill. What should I do?
A: If you feel your vehicle starting to slide sideways, turn downhill. This
should help straighten out the vehicle and prevent the side sl\
ipping. However,
a much better way to prevent this
is to get out and “walk the course” so you
know what the surface is like before you drive it.
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Your Driving and the Road
Stalling on an Incline
If your vehicle stalls when you’re crossing an incline, be sure you (and your
passengers) get out on the uphill side, even
if the door there is harder to
open. If you get out on the downhill side and the vehicle starts to roll over,
you’ll be right in its path.
If you have to walk down the slope, stay out of the path the vehicle will take
if ‘it does roll over.
AM440002
I CAUTION
A 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
I 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 you\
r 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
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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 th\
ese surfaces, it’s
very easy to lose control. On wet ice, for example, the tract\
ion
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.
I A Driving on frozen lakes, ponds or rivers can be dangerous. I
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
on
I y.
.
Driving In Water
Light rain causes no special off-road driving problems. But hea\
vy rain can
mean flash flooding, and flood waters demand extreme caution.
Find out how deep the water is before you drive through
it. If it’s deep
enough to cover your wheel hubs, axles, or exhaust pipe, don’\
t try it-you
probably won’t get through. Also, water that deep can damage\
your axle and
other vehicle parts.
If the water isn’t too deep, then drive through it slowly. At fast speeds, water
splashes on your ignition system and your vehicle can stall. S\
talling can also
occur
if you get your tailpipe under water. And, as long as your tailp\
ipe is
under water, you’ll never be able to start your engine. Whe\
n you go through
water, remember that when your brakes get wet, it may take you longer to
stop.
Driving through rushing water can be dangerous. Deep water can \
sweep your vehicle downstream and you and your passengers could\

drown.
If it’s only inches deep, it can still wash away the ground
from under your tires, and you could lose traction and roll t\
he vehicle
over. Don’t drive throuah rushina water. I
If you have a diesel engine, see “Driving Through Water (Diese\
l Engines)” in
the Index for more information on driving through water.
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