1998 GMC ENVOY Owners Manual

Payload
The payload capacity is shown on the CertificationRire
label. This is the maximum load capacity that your
vehicle can carry. Be sure to include the weight of the
occupants as part
of your load. If you added any
accessories or equipment after your vehicle left the
factory, remember to subtract the weight
of these things
from the payload.
Your dealer can help you with this.
Electronic Level Control
The rear of the vehicle is automatically kept level as you
load
or unload your vehicle. However, you should still
not exceed the
GVWR or the GAWR.
The ignition has to be on for the level control to work.
The system includes a small electric air compressor and
air-adjustable rear shock absorbers.
You may hear the compressor operating when you load
or unload your vehicle, and periodically
as the system
self-adjusts. This is normal. The compressor should operate for
brief periods
of time
If the sound continues for an extended period of time,
your vehicle needs service.
To keep your battery from
being drained. you may want to remove the
LD LEV
fuse in the fuse control panel until you can get your
vehicle serviced (see “Fuses and Circuit Breakers”
in
the Index).
Using heavier suspension components to get added
durability might not change your weight ratings.
Ask
your dealer to help you load your vehicle the right way.
NOTICE:
Your warranty does not cover parts or
components that fail because
of overloading.
ProCarManuals.com

Add-on Equipment
When you carry removable items, you may need to put a
limit on how many people you carry inside your vehicle.
Be sure
to weigh your vehicle before you buy and install
the new equipment.
Towing a Trailer
I NOTICE:
Your warranty doesn’t cover parts or
components that fail because of overloading.
A CAUTION:
If you don’t use the correct equipment and drive
properly, you can lose control when you pull a
trailer. For example,
if the trailer is too heavy, the
brakes may not work well
-- or even at all. You
and your passengers could be seriously injured.
Pull
a trailer only if you have followed all the
steps in this section. Ask your dealer for advice
and information about towing a trailer with
your vehicle.
I NOTICE:
Pulling a trailer improperly can damage your
vehicle and result in costly repairs not covered by
your warranty.
To pull a trailer correctly, follow
the advice in this part, and see your dealer for
important information about towing a trailer
with your vehicle.
4-43
ProCarManuals.com

Every vehicle is ready for some trailer towing. If yours
was built with trailering options, as many are, it’s ready
for heavier trailers. But trailering is different than just
driving your vehicle by itself. Trailering means changes
in handling, durability and fuel economy. Successful,
safe trailering takes correct equipment, and
it has to be
used properly.
That’s
the reason for this part. In it are many
time-tested, important trailering tips and safety rules. Many
of these are important for your safety and that of
your passengers.
So please read this section carefully
before you pull a trailer.
If You Do Decide To Pull A Trailer
If you do, here are some important points:
0
0
There are many different laws, including speed limit
restrictions, having to do with trailering. Make sure
your rig will be legal, not only where you live but
also where you’ll be driving.
A good source for this
information can be state or provincial police.
Consider using a sway control if your trailer
will
weigh 2,000 lbs. (900 kg) or less. You should always
use a sway control if your trailer will weigh more
than
2,000 Ibs. (900 kg). You can ask a hitch dealer
about sway controls.
0
0
0
Don’t tow a trailer at all during the first 500 miles
(800 km) your new vehicle is driven. Your engine,
axle or other parts could be damaged.
Then, during the first
500 miles (800 km) that you
tow a trailer, don’t drive over 50 mph (80 km/h) and
don’t make starts at full throttle. This helps your
engine and other parts of
your vehicle wear in at the
heavier loads.
You should use DRIVE
(D) (or, as you need to, a
lower gear) when towing a trailer. Operating your
vehicle
in DRIVE (D) when towing a trailer will
minimize heat buildup and extend the life
of
your transmission.
Three important considerations have to
do with weight:
the weight of the trailer,
0 the weight of the trailer tongue
0 and the weight on your vehicle’s tires.
4-44
ProCarManuals.com

Weight of the Trailer
How heavy can a trailer safely be?
It depends on how you plan to use your rig. For
example, speed, altitude, road grades, outside
temperature and how much
your vehicle is used to pull a
trailer are all important. And,
it can also depend on any
special equipment that you have
on your vehicle.
The trailer should never weigh more than
5,000 lbs.
(2 268 kg). But even that can be too heavy.
Maximum trailer weight is calculated assuming the
driver and one passenger are
in the tow vehicle and it
has all the required trailering equipment. The weight of
additional optional equipment, passengers and cargo
in
the tow vehicle must be subtracted from the maximum
trailer weight.
You can ask your dealer for OUT trailering information or
advice, or you can write us
at the address listed in your
Warranty and Owner Assistance Information Booklet.
In Canada. write to:
General Motors of Canada Limited
Customer Communication Centre 1908 Colonel Sam Drive
Oshawa, Ontario
LlH 8P7
Weight of the Trailer Tongue
The tongue load (A) of any trailer is an important
weight to measure because it affects the total or gross
weight of your vehicle. The Gross Vehicle Weight
(GVW) includes the curb weight
of the vehicle, any
cargo you may carry
in it, and the people who will be
riding in the vehicle. And
if you will tow a trailer, you
must add the tongue load to the GVW because your
vehicle will be carrying that weight, too, See “Loading
Your Vehicle”
in the Index for more information about
your vehicle’s maximum load capacity.
4-45
1
ProCarManuals.com

A B
If you’re using a weight-carrying hitch, the trailer
tongue (A) should weigh
10 percent of the total loaded
trailer weight
(B). If you’re using a weight-distributing
hitch, the trailer tongue
(A) should weigh 12 percent of
the total loaded trailer weight (B).
After you’ve loaded your trailer, weigh the trailer and
then the tongue, separately, to see if the weights are
proper. If they aren’t,
you may be able to get them right
simply by moving some items around in the trailer.
1 Total Weight on Your Vehicle’s Tires
Be sure your vehicle’s tires are inflated to the upper
limit for cold tires. You’ll find these numbers on the
CertificatiodTire label on the driver’s door edge, above
the door latch, or see “Tire Loading”
in the Index. Then
be sure
you don’t go over the GVW limit for your
vehicle, including the weight
of the trailer tongue.
Hitches
It’s important to have the correct hitch equipment.
Crosswinds, large trucks going by and rough roads are a
few reasons why you’ll need the right hitch. Here are
some rules to follow:
0 If you’ll be pulling a trailer that, when loaded, will
weigh more than
3,500 lbs. (1 589 kg), be sure to use
a properly mounted, weight-distributing hitch and
sway control of the proper size. This equipment is
very important for proper vehicle loading and good
handling when you’re driving.
0 Will you have to make any holes in the body of your
vehicle when you install
a trailer hitch?
If you do, then be sure to seal the holes later when
you remove the hitch. If you don’t seal them, deadly
carbon monoxide (CO) from your exhaust can get
into your vehicle (see “Carbon Monoxide” in the
Index). Dirt and water can, too.
4-46
ProCarManuals.com

Safety Chains
You should always attach chains between yo~~r vehicle
and yo~lr trailer.
Cross the safety chains under the tongue
of the trailer
so that the tongue will not drop to the road
if it becomes separated from the hitch. Instructions
about safety chains may be provided by the hitch
manufacturer
or by the trailer manufxturer. Follow the
manufacturer's recommendation
for attaching safety
chains and do not attach them to the bumper. Always
leave just enough slack
so you can turn with your rig.
And, never
allow safety chains to drag on the ground.
Trailer Brakes
If your trailer weighs mcxe than 1,000 Ibs. (450 kg)
loaded, then
it needs its own brakes -- and they must be
adequate.
Be sure to read and follow the instructions for
the trailer brakes
so you'll be able to install. adjust and
maintain them properly. Your
trailer-s brake system can tap into the vehicle's
hydraulic brake system only if:
0 The trailer parts can withstand 3,000 psi
(20 650 kPa) of pressure.
0 The trai1er.s brake system will use less than
0.02 cubic inch (0.3 cc) of fluid from your vehicle's
master cylinder. Otherwise, both braking systems
won't
work well. You could even lose your brakes.
If everything checks out this fir, then make the brake
fluid tap at the port on the master cylinder that sends
fluid to the rear brakes. But don't
LIS~ copper tubing for
this.
If you do, it will bend and finally break off. Use
steel brake tubing.
4-47
I
ProCarManuals.com

Driving with a Trailer
A CAUTION: I
0
0
0
If you have a rear-most window open and you
pull a trailer with your vehicle, carbon monoxide
(CO) could come into your vehicle. You can’t see
or smell
CO. It can cause unconsciousness or
death. (See ‘(Engine Exhaust” in the Index.) To
maximize your safety when towing a trailer:
Have your exhaust system inspected for
leaks, and make necessary repairs before
starting on your trip.
Keep the rear-most windows closed.
If exhaust does come into your vehicle
through a window in the rear or another
opening, drive with your front, main
heating or cooling system on and with the
fan on any speed. This will bring fresh,
outside air into your vehicle.
Do not use
RECIRCULATION because it only
recirculates the air inside your vehicle. (See
“Comfort Controls” in the Index.)
Towing a trailer requires a certain amount of experience, ~
Before setting out for the open road, you’ll want to get
to know your rig. Acquaint yourself with the feel of
handling and braking with the added weight of the
trailer. And always keep in mind that the vehicle you
arc
driving is now a good deal longer and not nearly as
responsive as your vehicle is by itself.
Before you
start, check the trailer hitch and platform
(and attachments), safety chains, electrical connector,
lamps, tires and mirror adjustment. If the trailer has
electric brakes, start your vehicle and trailer moving and
then apply the trailer brake controller by hand to be sure
the brakes are working. This lets you check your
electrical connection at the same time.
During your trip, check occasionally to
be sure that the
load is secure, and that the lamps and any trailer brakes
are still working.
Following Distance
Stay at least twice as far behind the vehicle ahead as you 1
would when driving your vehicle without a trailer. This
can help you avoid situations that require heavy braking
and sudden turns.
4-48
ProCarManuals.com

Passing
You’ll need more passing distance up ahead when
you’re towing a trailer. And, because you’re
a good deal
longer,
you’ll need to go much farther beyond the
passed vehicle before you can return to your lane.
Backing Up
Hold the bottom of the steering wheel with one hand.
Then,
to move the trailer to the left, just move that hand
to the left. To move the trailer to the right, move your
hand to the right. Always back up slowly and,
if
possible, have someone guide you.
Making Turns
NOTICE:
~~
Making very sharp turns while trailering could
cause the trailer to come in contact with the
vehicle. Your vehicle could be damaged. Avoid
making very sharp turns while trailering.
When you’re turning with a trailer, make wider turns than
normal.
Do this so your trailer won’t strike soft shoulders,
curbs, road signs, trees or other objects.
Avoid jerky or
sudden maneuvers. Signal well
in advance.
Turn Signals When Towing a Trailer
When you tow a trailer, your vehicle has to have extra
wiring and a heavy-duty turn signal flasher.
The arrows on your instrument panel will flash
whenever you signal a
turn or lane change. Properly
hooked up,
the trailer lamps will also flash, telling other
drivers you’re about to
turn, change lanes or stop.
When towing a trailer, the arrows
on your instrument
panel will flash for turns even
if the bulbs on the trailer
are burned out. Thus, you may think drivers behind you
are seeing your signal when
they are not. It’s important
to check occasionally
to be sure the trailer bulbs are
still working.
4-49
I
ProCarManuals.com