trailer GMC ENVOY 1998 User Guide

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.
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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.
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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.
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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.
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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.
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Driving On Grades
Reduce speed and shift to a 1owe.r gear Iwfow you start
down a long or steep downgrade.
If you don’t shift
down. you might have to use your brakes
so much that
they would get hot and no longer work well.
On
a long uphill grade, shift down and reduce your
speed to around
45 mph (70 km/h) to reduce the
possibility of engine and transmission overheating.
You should use DRIVE
(D) 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.
When towing at high altitude
on steep uphill grades,
consider the following: Engine coolant
will boil at a lower
temperature than at normal altitudes.
If you twn your
engine off imnlediately after towing at high altitude on
steep uphill grades, your vehicle may show signs similar to
engine overheating.
To avoid this, let the engine run while
parked (preferably on level ground)
with the automatic
transmission
in PARK (PI for a few minutes before turning
the engine off.
If you do get the overheat warning. see
”Engine Overheating”
in the Index.
Parking on Hills
You really should not park your vehicle, with a trailer
attached.
on a hill. If‘ something goes wrong, your rig
could start
to move. People can be injured, and both
your vehicle and the trailer can be damaged.
But
if you ever have to park your rig on a hill, here‘s
how
to do it:
1.
-. 3
3.
4.
5.
Apply your regular brakes, but don’t shift into
PARK
(P) yet. Then turn your wheels into the curb
if facing downhill or into traffic if facing uphill.
Have someone place chocks under the trailer wheels.
When the wheel chocks are
in place, release the
regular brakes
until the chocks absorb the load.
Reapply the regular brakes. Then apply your parking
brake, and then shift into PARK
(P).
Release the regular brakes.
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When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
0 Start your engine;
Shift into a gear; and
0 Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when you’re
pulling
a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission fluid (don’t
overfill), engine
oil, axle lubricant, belt, cooling system
and brake adjustment. Each of these is covered in this
manual, and the Index will help you find them quickly.
If you’re trailering, it’s
a good idea to review these
sections before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
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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.
0
0
0
0
0
0
0
0
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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io Stea 5 Coming From Your Engine
~i you get the overheat warning but see or hear no
steam, the problem may not be too serious. Sometimes
the engine can get
a little too hot when you:
0 Climb a long hill on a hot day.
Stop after high-speed driving.
Idle for long periods in traffic.
Tow a trailer. See “Driving on Grades” in the Index.
If you get the overheat.warning with no sign of steam,
try this for a minute or
so:
1. Turn off your air conditioner.
2. Turn on your heater to full hot at the highest fan
speed and open the window
as necessary.
3. If you’re in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving
-- DRIVE (D) or THIRD (3).
If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about
10 minutes.
If the warning doesn’t come back on, you can
drive normally.
If the warning continues, pull over, stop, and park your
vehicle right away.
If there’s still no sign of steam, push the accelerator until
the engine speed is about twice as fast as normal idle
speed. Bring the engine speed back to normal idle speed
after two or three minutes.
Now see if the warning stops.
But then, if you still have the warning, turn ojfthe
engine nnd
get everyone out of the vehicle until it
cools down.
You may decide not to lift the hood but to get service
help right away.
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Engine Fan Noise
This vehicle has a clutched engine cooling fan. When the
clutch is engaged, the fan spins faster to provide more air
to cool the engine. In most everyday driving conditions,
the clutch is
not engaged. This improves fuel economy and
reduces
fan noise. Under heavy vehicle loading, trailer
towing and/or high outside temperatures, the fan speed
increases when the clutch engages.
So you may hear an
increase in fan noise. This is normal and should not be
mistaken
as the transmission slipping or making extra
shifts. It is merely the cooling system functioning properly.
The fan will slow down when additional cooling is not
required and the clutch disengages.
You may
also hear this fan noise when you start the
engine. It will go away
as the fan clutch disengages.
If a Tire Goes Flat
It’s unusual for a tire to “blow out” while you’re driving,
especially if you maintain your tires properly.
If air goes
out of
a tire, it’s much more likely to leak out slowly.
But
if you should ever have a “blowout,” here are a few
tips about what to expect and what to do:
If
a front tire fails, the flat tire will create a drag that
pulls the vehicle toward that side.
Take your foot off the
accelerator pedal and grip
the steering wheel firmly.
Steer to maintain lane position, and then gently brake to
a stop well out of the traffic lane.
A rear blowout, particularly on a curve, acts much like a
skid and may require the same correction you’d use in a
skid. In any rear blowout, remove your foot from the
accelerator pedal. Get the vehicle under control by
steering the
way you want the vehicle to go. It may be
very bumpy and noisy, but you can
still steer. Gently
brake to
a stop -- well off the road if possible.
If a tire goes flat, the next part shows how to use your
iacking equipment to change
a flat tire safely. u Y a. c
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