1993 GMC SIERRA Owners Manual

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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Your Driving and the Road
After Off-Road Driving
Remove any brush or debris that has collected on the underbody\
, chassis, or
under the hood. These accumulations can be a fire hazard.
After operation in mud or sand, have the brake linings cleaned\
and checked. These substances can cause glazing and uneven braking. Check th\
e body
structure, steering, suspension, wheels, tires, and exhaust syste\
m for damage.
Also, check the fuel lines and cooling system for any leakage.
Your vehicle will require more frequent service due
to off-road use. Refer to
Section
7 for additional information.
Driving at Night
I
--.
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- AM450002 I
Night driving is more dangerous than day driving. One reason is that some
drivers are likely
to be impaired-by alcohol or drugs, with night vision
problems, or by fatigue.
Here are some tips on night driving.
Drive defensively. Remember, this is the most dangerous time.
Don’t drink and drive (See “Drunken Driving” in the Index for more on
this problem).
Adjust your inside rear view mirror to reduce the glare from headlights
Since you can’t see as well, you may need to slow down and keep
behind
you.
more space between you and other vehicles. It’s hard
to tell how fast
the vehicle ahead is going just
by looking at its taillights.
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Slow down, especially on higher speed roads. Your headlights ca\
n light
In remote areas, watch for animals.
If you’re tired, pull off the road in a safe place and rest.
up only
so much road ahead.
Night Vision
No one can see as well at night as
in the daytime. But as we get older
these differences increase.
A 50-year-old driver may require at least twice as
much light to see the same thing at night as a 20-year-old.
What you do in the daytime can also affect your night vision.\
For example, if
you spend the day in bright sunshine you are wise to wear sunglasses. Your
eyes will have less trouble adjusting to night.
But if you’re driving, don’t wear sunglasses at night. Th\
ey may cut down on
glare from headlights, but they also make a lot of things inv\
isible that should
remain visible-such as parked cars, obstacles, pedestrians, or e\
ven trains
blocking railway crossings. You may want
to put on your sunglasses after you
have pulled into a brightly-lighted service or refreshment area.\
Eyes shielded
from that glare may adjust more quickly to darkness back on t\
he road. But
be sure to remove your sunglasses before you leave the service\
area.
You can be temporarily blinded by approaching lights.
It can take a second or
two, or even several seconds, for your eyes to readjust to the dark. When
you are faced with severe glare (as from a driver who doesn’\
t lower the high
beams, or a vehicle with misaimed headlights), slow down a little. Avoid\

staring directly into the approaching lights. If there is a line of opposing
traffic, make occasional glances over the line of headlights to make certain
that one of the vehicles isn’t starting to move into your lane. Once you are
past the bright lights, give your eyes time to readjust before\
resuming speed.
High Beams
If the vehicle approaching you has its high beams on, signal by \
flicking yours
to high and then back to low beam. This is the usual signal to lower the
headlight beams.
If the other driver still doesn’t lower the beams, resist the
temptation to put your high beams on. This only makes
two half-blinded
drivers.
On a freeway, use your high beams only in remote areas where \
you won’t impair approaching drivers. In some places, like cities, using \
high beams is
illegal.
When you follow another vehicle on a freeway or highway, use \
low beams.
True, most vehicles now have day-night mirrors that enable the \
driver to
reduce glare. But outside mirrors are not
of this type and high beams from
behind can bother the driver ahead.
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Your Driving and the Road
A Few More Night Driving Suggestions
Keep your windshield and all the glass on your vehicle clean-i\
nside and out.
Glare at night is made much worse by dirt on the glass. Even\
the inside
of
the glass can build up a film caused by dust. Tobacco smoke \
also makes inside glass surfaces very filmy and can be a vision hazard
if it’s left there.
Dirty glass makes lights dazzle and flash more than clean glas\
s would,
making the pupils of your eyes contract repeatedly. You might even want to
keep a cloth and some glass cleaner in your vehicle
if you need to clean
your glass frequently.
Remember that your headlights light up far less of a roadway \
when you are
in a turn or curve.
Keep your eyes moving; that way, it’s easier to pick out d\
imly lighted objects.
Just as your headlights should be checked regularly for proper \
aim,
so should
your eyes be examined regularly. Some drivers suffer from night\
blindness-the inability to see in dim light-and aren’t even aware of
it.
Driving in the Rain
Rain and wet roads can mean driving trouble. On a wet road y\
ou can’t stop,
accelerate or turn as well because your tire-to-road traction i\
sn’t as
good as
on
dry roads. And, if your tires don’t have much tread left, you’ll get even
less traction.
It’s always wise to go slower and be cautious if rain starts to fall while you
are driving. The surface may get wet suddenly when your reflex\
es are tuned
for driving on
dry pavement.
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