lock GMC ENVOY 1998 Workshop Manual

Off-Road Driving with Your GM
Four-Wheel-Drive Vehicle
Also, see "Anti-Lock Brakes" in the Index.
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
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-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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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.
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.
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. 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.
0 you have less time to react.
0 you have more vehicle bounce when you drive
over obstacles.
0 you’ll need more distance for braking, especially
since you’re on an unpaved surface.
A c. u7c-i:
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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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
matt how
well built the vehicle.
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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Many hills are simply too steep for any vehicle. If
you drive up them, you 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.
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
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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 Inaneuvers'!
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 of'ten have
ruts, gullies, troughs and exposed rocks because they
are more susceptible to the effects of erosion.
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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
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do, and there are some things you must not do.
First, here’s what you
should do:
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
to REVERSE
(R), release the parking brake, and
slowly back down the
hill in REVERSE (R).
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) 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).
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 r7ot 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) 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.
0 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.
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
PARK (P) 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.
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What’s the worst time for this? “Wet ice.” Very cold
snow or ice can be slick and hard to drive on.
But wet
ice can be even more trouble because
it may offer the
least traction
of all. You can get wet ice when it’s about
freezing
(32°F; OOC) and freezing rain begins to fall.
Try to avoid driving on wet ice
until salt and sand crews
can get there. Whatever
the condition
-- smooth ice, packed, blowing
or loose snow
-- drive with caution.
Accelerate gently. Try not to break the fragile traction.
If
you accelerate too fast, the drive wheels will spin and
polish the surface under the tires even more.
Your anti-lock brakes improve your vehicle’s stability
when you make
a hard stop on a slippery road. Even
though
you have an anti-lock braking system, you’ll
want to begin stopping sooner than you would on dry
pavement. See “Anti-Lock”
in the Index.
Allow greater following distance on any
slippery road.
Wdtch for slippery spots. The road might be fine
until you hit a spot that’s covered with ice. On an
otherwise clear road, ice patches may appear
in
shaded areas where the sun can’t reach: around
clumps
of trees, behind buildings or under bridges.
Sometimes the surface
of a curve or an overpass may
remain icy when
the surrounding roads are clear. If
you see a patch of ice ahead of you, brake before you
are on
it. Try not to brake while you’re actually on
the ice, and avoid sudden steering maneuvers.
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Snow can trap exhaust gases under your vehicle.
This can cause
deadly CO (carbon monoxide) gas
to get inside. CO could overcome
you and kill
you. You can’t see it
or smell it, so you might not
know it
is in your vehicle. Clear away snow from
around the base
of your vehicle, especially any
that is blocking your exhaust pipe. And check
around again from time to time to be sure snow
doesn’t collect there.
Open a window just
a little on the side of the
vehicle that’s away from the wind. This will help
keep
CO out.
Run your engine only as long as you must. This saves
fuel. When you
run the engine. make it go a little faster
than just idle. That is. push the accelerator slightly. This
uses less fuel for the heat that you get and
it keeps the
battery charged.
YOLI will need a well-charged battery to
restart the vehicle, and possibly for signaling later
on
with your headlamps. Let the heater run for a while.
Then, shut the engine off and close the window almost
all the way to preserve the heat. Start the engine again
and repeat this only when you feel really uncomfortable
from the cold.
But do it as little as possible. Preserve the
fuel
as long as you can. To help keep warm, you can get
out of the vehicle and do some fairly vigorous exercises
every half hour or
so until help comes.
Recreational Vehicle Towing
Vehicles with the electronic shift transfer case require
special modifications before they can be towed
in this
manner. Please contact your dealer
.for the towing
information that is appropriate
for yoc~r
particular vehicle.
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Trailer Wiring Harness
The heavy-duty trailer wiring is an eight-wire harness
assembly. The harness is stored under the vehicle, on the
driver’s side corner frame rear crossmember. The
heavy-duty trailer wiring has a 30-amp feed wire
with
an in-line fuse located by the junct.ion block. See “Fuses
and Circuit Breakers”
in the Index. The harness does not
have a cannector and should be wired by
a qualified
electrical technician. The technician can use the
following color code chart when connecting the wiring
harness
to your trailer.
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Dark Blue: Use for electric trailer brakes or
auxiliary wiring.
Red: Use for battery charging;
it connects to the
starter solenoid.
Light Green: Back-up lamps.
Brown: Taillamps and parking lamps.
Yellow: Left stoplamp and turn signal.
Dark Green: Right stoplamp
and turn signal.
White (Heavy Gage): Ground wire.
White (Light Gage): Auxiliary stoplamp.
Securely attach the harness to the trailer, then tape or
strap
it to your vehicle’s frame rail. Be sure you leave it
loose enough so the wiring doesn’t bend or break, but
not
so loose that it drags on the ground. Store the
harness
in its original place. Wrap the harness together
and tie
it neatly so it won’t be damaged.
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JTION:
A vehicle can fall from a car carrier if it isn’t
adequately secured. This can cause
a collision,
serious personal injury and vehicle damage. The
vehicle should be tightly secured with chains or
steel cables before it is transported.
Don’t use substitutes (ropes, leather straps,
canvas webbing, etc.) that can be cut by sharp
edges underneath the towed vehicle. Always use
T-hooks inserted in the T-hook slots. Never use
J-hooks. They will damage drivetrain and
suspension components.
When your vehicle is being towed, have the ignition key
turned
to the OFF position. The steering wheel should
be clamped
in a straight-ahead position with a clamping
device designed for towing service.
Do not use the
vehicle’s steering column lock for this. The transmission
should be in NEUTRAL
(N) and the transfer case
should be
in 2HI. The parking brake should be released.
If your vehicle has no electrical power, the electrical
solenoid lock
must be overridden to shift from
PARK (P) to NEUTRAL (N). Follow these steps:
1 I Remove the wood trim panel surrounding the base
2. Reach inside the console and find the white of the shift lever.
solenoid lever.
(ii
3. Push the solenoid
lever down.
4. While holding the solenoid lever in the unlock
position, press the shift lever button and shift into
NEUTRAL
(N).
5. Release the solenoid lever and replace the trim panel.
Don’t have your vehicle towed on the drive wheels
unless
you must. If the vehicle must be towed on the
drive wheels, be sure to follow the speed and distance
restrictions later
in this section or your transmission will
be damaged. If these limitations must be exceeded, then
the drive wheels have to be supported
on a dolly.
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How to Add Coolant to the Radiator
2. Then keep turning the pressure cap, but now push
down as you
turn it. Remove the pressure cap.
I. You can remove the radiator pressure cap when the
cooling
system. including the radiator pressure cap and
upper radiator hose, is no longer hot. Turn the pressure
cap slowly counterclockwise
until it first stops. (Don’t
press down while turning the pressure cap.)
If you hear a hiss, wait for that to stop. A hiss means
there is still some pressure left.
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Changing a Flat Tire
If a tire goes flat, avoid further tire and wheel damage
by driving slowly to a level place. Turn on
your hazard
warning flashers.
A CAUTION:
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Changing a tire can cause an injury. The vdcle
can slip
off the jack and roll over you or other
people. You and they could be badly injured.
Find a level place to change your tire. To help
prevent the vehicle from moving:
1. Set the parking brake firmly.
2. Put the shift lever in PARK (P).
3. lbrn off the engine.
4. Put the wheel blocks at the front and
rear of the tire farthest away from the
one being changed. That would be the
tire on the other side of the vehicle,
at
the opposite end.
The following steps will tell you how to use the jack and
change a tire.
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