GMC ENVOY 1998 Owners Manual

Driving Downhill
When off-roading takes you uownhill, you'll want to
consider
a number of things:
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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 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?
If you decide you can go down a hill safely. then try to
keep your vehicle headed straight down. and use
a low
they won't have to do
all the work. Descend slowly,
keeping your vehicle under control at
all times.
b "ear. This way, engine drag can help your brakes and
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A CAUTION:
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 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 ~CI-OSS.
You could roll over
if you don't drive straight down.
Never
go downhill with the transmission in
NEUTRAL (N). This is crdled "free-wheeling." Your
brakes
will have to do all the work and could
overheat and fade.
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Q.' Am I likely to stall when going downhill?
A: It's much nm-e likely to happen going uphill. But if
it happens going downhill, here's what to do.
0 Stop your vehicle by applying the regular brakes.
Shift to PARK (P) and. while still braking. restart
Apply the parking
brake.
the engine.
Shift back to a low gear, release the parking brake,
and drive straight d6wn.
0 If the engine won't start, get out and get
Driving Across an Incline
Sooner or later, an off-road trail will probab lelp. y go
across
the incline
of a hill. If this happens, you have to decide
whether to
try to dri\:e across the incline. Here are some
things to consider:
0 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
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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
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 n1oI-e.
e orass can cause your tires to slip sideways. downhill.
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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Driving across an incline that’s too steep will
make your vehicle 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.
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 slipping. 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.
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.
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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.
LA CAU-ION:
Driving on frozen lakes, ponds or ~ ~ rers 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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Driving in Water
Light rain causes no special off-road driving problems.
But heavy 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. Stalling
can also occur if you
get your tailpipe under water. And, as long as your
tailpipe
is under water? you'll never be able to start your
engine. When 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 shallow water, it can still wash away the
ground from under your tires, and you could lose
traction and roll the vehicle over. Don't drive through rushing water.
See "Driving Through Wdter" in the Index for more
information
on driving through water.
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 the body structure,
steering, suspension, wheels, tires and exhaust system
for
da1nage. Also, check the fuel lines and cooling
system for any leakage.
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Your vehicle will require more frequent service due to
off-road use. Refer to the Maintenance Schedule for
additional information.
Drivin at Night
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.
0 Drive defensively.
0 Don't drink and drive.
0 Adjust your inside rearview mirror to reduce the
0 Since you can't see as well, you may need to slow
c2 "lare from headlamps behind you.
down and keep more space between
you and
other vehicles.
0 Slow down, especially on higher speed roads. Your
headlamps can light up only
so much road ahead.
In remote areas, watch for animals.
If you're tired. pull off the road in a safe place
and rest.
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. They may cut
down on glare from headlamps, but they also make a lot
of things invisible.
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You can be temporarily blinded by approaching
headlamps. 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 headlamps), slow down a little. Avoid staring
directly into the approaching headlarnps.
Keep your windshield and all the
glass oi=ryour vehicle
clean
-- inside 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. Dirty glass makes
lights dazzle and flash more than clean glass would,
making
the pupils of your eyes contract repeatedly.
Remember that your headlamps 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 dimly
lighted objects. Just
as your headlamps 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 Rain and on Wet Roads
Rain and wet roads can mean driving trouble. On a wet
road, you can‘t stop, accelerate or turn
as well because
your tire-to-road traction isn‘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 reflexes are
tuned for driving
on dry pavement.
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The heavier the rain, the harder it is to see. Even if your
windshield wiper blades are
in good shape, a heavy rain
can make
it harder to see road signs and traffic signals,
pavement markings, the edge
of the road and even
people walking.
It’s wise to keep your wiping equipment in good shape
and keep your windshield washer tank filled
with
washer fluid. Replace your windshield wiper inserts
when they show signs
of streaking or missing areas on
the windshield, or when strips of rubber start
to separate
from
the inserts. Driving
too fast through large water puddles or even
going through some car washes can cause problems, too.
The water may affect your brakes. Try to avoid puddles.
But
if you can’t, try to slow down before you hit them.
Wet brakes can cause accidents. They won’t work
as well in a quick stop and may cause pulling to
one side. You could lose control
of the vehicle.
After driving through a large puddle
of water or
a car wash, apply your brake pedal lightly until
your brakes work normally.
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Hydroplaning
Hydroplaning is dangerous. So much water can build up
under your tires that they can actually ride on the water.
This can happen
if the road is wet enough and you’re
going fast enough. When your vehicle is hydroplaning,
it has little or no contact with the road.
Hydroplaning doesn‘t happen often.
But it can if your
tires do not have much tread
or if the pressure in one or
more
is low. It can happen if a lot of water is standing on
the road. If you can see reflections from trees, telephone
poles or other vehicles, and raindrops ”dimple” the
water‘s surface, there could be hydroplaning.
Hydroplaning usually happens at higher speeds. There
just isn’t a hard and fdst rule about hydroplaning. The
best advice
is to slow down when it is raining.
1 )riving Through Deep Standing W ’ Fr
NOTICE:
If you drive too quickly through deep puddles or
standing water, water can come in through your
engine’s air intake and badly damage your
engine. Never drive through water that
is slightly
lower than the underbody
of your vehicle. If’ you
can’t avoid deep puddles or standing water, drive
through them very slowly.
Some Other Rainy Weather Tips
0 Besides slowing down, allow some extra following
distance.
And be especially carefir1 when you pass
another vehicle. Allow yourself more clear room
ahead, and be prepared
to have your view restricted
by road spray.
Have good tires with proper tread depth. (See
“Tires”
in the Index.)
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City Driving One of the biggest problems with city streets is the
amount of traffic on them.
You'll want to watch out for
what the other drivers are doing and pay attention to
traffic signals.
Here are ways to increase your safety
in city driving:
0 Know the best way to get to where you are going. Get
a city map and plan your trip into an unknown part of
the city just as you would for a cross-country trip.
0 Try to use the freeways that rim and crisscross most
large cities. You'll save time and energy. (See the
next part, "Freeway Driving.")
0 Treat a green light as a warning signal. A traffic light
is there because the corner
is busy enough to need it.
When a light turns green, and just before you start to
move, check both ways for vehicles that have not
cleared the intersection or may be running the
red light.
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