towing GMC SONOMA 2004 User Guide

Your Driving, the Road, and Your Vehicle..........4-2
Defensive Driving...........................................4-2
Drunken Driving.............................................4-2
Control of a Vehicle........................................4-5
Braking.........................................................4-6
Locking Rear Axle..........................................4-8
Steering........................................................4-9
Off-Road Recovery.......................................4-11
Passing.......................................................4-11
Loss of Control.............................................4-13
Off-Road Driving with Your Four-Wheel-Drive
Vehicle....................................................4-14
Driving at Night............................................4-27
Driving in Rain and on Wet Roads..................4-29
City Driving..................................................4-32Freeway Driving...........................................4-33
Before Leaving on a Long Trip.......................4-34
Highway Hypnosis........................................4-35
Hill and Mountain Roads................................4-36
Winter Driving..............................................4-38
If You Are Stuck: In Sand, Mud,
Ice or Snow..............................................4-42
Towing..........................................................4-45
Towing Your Vehicle.....................................4-45
Recreational Vehicle Towing...........................4-45
Loading Your Vehicle....................................4-45
Truck-Camper Loading Information..................4-52
Trailer Recommendations...............................4-54
Pickup Conversion to Chassis Cab..................4-54
Towing a Trailer...........................................4-55
Section 4 Driving Your Vehicle
4-1

Rocking Your Vehicle To Get It Out
First, turn your steering wheel left and right. That will
clear the area around your front wheels. If you have a
four-wheel-drive vehicle, shift into 4HI. Then shift
back and forth between REVERSE (R) and a forward
gear, spinning the wheels as little as possible. Release
the accelerator pedal while you shift, and press lightly
on the accelerator pedal when the transmission is
in gear. By slowly spinning your wheels in the forward
and reverse directions, you will cause a rocking
motion that may free your vehicle. If that does not get
you out after a few tries, you may need to be towed out.
Or, you can use your recovery hooks if your vehicle
has them. If you do need to be towed out, seeTowing
Your Vehicle on page 4-45.
Using the Recovery Hooks
Your vehicle may be equipped with recovery hooks. The
hooks are provided at the front of your vehicle. You
may need to use them if you’re stuck off-road and need
to be pulled to some place where you can continue
driving.
4-43

Towing
Towing Your Vehicle
Consult your dealer or a professional towing service if
you need to have your disabled vehicle towed. See
Roadside Assistance Program on page 7-6.
If you want to tow your vehicle behind another vehicle
for recreational purposes (such as behind a motorhome),
see “Recreational Vehicle Towing” following.
Recreational Vehicle Towing
Recreational vehicle towing means towing your vehicle
behind another vehicle — such as behind a motorhome.
The two most common types of recreational vehicle
towing are known as “dinghy towing” (towing your
vehicle with all four wheels on the ground) and “dolly
towing” (towing your vehicle with two wheels on
the ground and two wheels up on a device known
as a “dolly”).
Your vehicle was not designed to be towed with any of
its wheels on the ground. If your vehicle must be
towed, seeTowing Your Vehicle on page 4-45.
Loading Your Vehicle
It is very important to know how much weight your
vehicle can carry. This weight is called the vehicle
capacity weight and includes the weight of all occupants,
cargo and all nonfactory-installed options. Two labels
on your vehicle show how much weight it may properly
carry, the Tire and Loading Information label and the
Certification/Tire label.
{CAUTION:
Do not load your vehicle any heavier than the
GVWR, or either the maximum front or rear
GAWR. If you do, parts on your vehicle can
break, and it can change the way your vehicle
handles. These could cause you to lose
control and crash. Also, overloading can
shorten the life of your vehicle.
4-45

Steps for Determining Correct Load Limit
1. Locate the statement “The combined weight of
occupants and cargo should never exceed XXX
pounds” on your vehicle placard.
2. Determine the combined weight of the driver and
passengers that will be riding in your vehicle.
3. Subtract the combined weight of the driver and
passengers from XXX kilograms or XXX pounds.
4. The resulting figure equals the available amount of
cargo and luggage load capacity. For example, if
the “XXX” amount equals 1400 lbs. and there will be
five 150 lb. passengers in your vehicle, the
amount of available cargo and luggage load
capacity is 650 lbs. (1400−750 (5 x 150) =
650 lbs.).
5. Determine the combined weight of luggage and
cargo being loaded on the vehicle. That weight
may not safely exceed the available cargo
and luggage load capacity calculated in Step 4.
6. If your vehicle will be towing a trailer, the load from
your trailer will be transferred to your vehicle.
Consult this manual to determine how this reduces
the available cargo and luggage load capacity of
your vehicle. SeeTowing a Trailer on page 4-55for
information on towing a trailer, towing safety
rules and trailering tips.
Loading Your Vehicle
Item Description Total
AVehicle Capacity
Weight for Example 1=1,000 lbs
(455 kg)
BSubtract Occupant
Weight @ 150 lbs
(76 kg)×2=300 lbs (138 kg)
CAvailable Occupant and
Cargo Weight =700 lbs (317 kg) Example 1
4-47

If your slide-in camper and its load weigh less than the
CWR, the center of gravity zone for your vehicle
may be larger.
Your dealer can help you make a good vehicle-camper
match. He’ll also help you determine your CWR.
Secure loose items to prevent weight shifts that could
affect the balance of your vehicle. When the truck
camper is loaded, drive to a scale and weigh on the
front and on the rear wheels separately to determine
axle loads. Individual axle loads should not exceed
either of the Gross Axle Weight Ratings (GAWR). The
total of the axle loads should not exceed the Gross
Vehicle weight Rating (GVWR). These ratings are given
on the vehicle certification label that is located on the
rear of the passenger’s door. If weight ratings are
exceeded, move or remove items to bring all weights
below the ratings.
If you want more information on curb weights, cargo
weights, cargo weight rating and the correct center
of gravity zone for your vehicle, your dealer can help
you. Just ask for a copy of “Consumer Information,
Truck-Camper Loading.”Trailer Recommendations
You must subtract your hitch load from the CWR for
your vehicle. Weigh your vehicle with your trailer
attached, so that you won’t go over the GVWR or the
GAWR.
You’ll get the best performance if you spread out the
weight of your load the right way, and if you choose the
correct hitch and trailer brakes.
For more information, seeTowing a Trailer on page 4-55
later in this section.
Pickup Conversion to Chassis Cab
General Motors is aware that some vehicle owners may
consider having the pickup box removed and a
commercial or recreational body installed. However, we
recommend that conversions of this type not be done
to pickups. Owners should be aware that, as
manufactured, there are differences between a chassis
cab and a pickup with the box removed which may
affect vehicle safety. For specific information on
this pickup, contact GM Customer Assistance. See
Customer Assistance Offices on page 7-4.
4-54

Towing a Trailer
{CAUTION:
If you do not 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.
Notice:Pulling a trailer improperly can damage
your vehicle and result in costly repairs that would
not be covered by your warranty. Always follow
the instructions in this section and check with your
dealer for more information about towing a trailer
with your vehicle.Your vehicle may be able to tow a trailer. To identify
what the vehicle trailering capacity is for your vehicle,
you should read the information in “Weight of the Trailer”
that appears later in this section.
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, accelleration, braking, 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.
4-55

If You Do Decide To Pull A Trailer
If you do, here are some important points:
•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. See “Hitches” later
in this section.
•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 may want to shift the transmission to THIRD (3)
or, if necessary, a lower gear selection if the
transmission shifts too often (e.g., under heavy
loads and/or hilly conditions). If you have a manual
transmission and you are towing a trailer, it’s
better not to use the highest gear.Three important considerations have to do with weight:
•the weight of the trailer,
•the weight of the trailer tongue
•and the weight on your vehicle’s tires.
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 following chart shows how much your trailer can
weigh, based upon your vehicle model and options.
Maximum trailer weight is calculated assuming only the
driver is 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.
The weight of the trailer tongue also affects trailering
capacity. See “Weight of the Trailer Tongue” next.
4-56

If you’ll be pulling a trailer, that when loaded, will weigh
more than 5,000 lbs (2 270 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 driving. You should always use a sway control
if your traile will weigh more than these limits. You can
ask a hitch dealer about sway controls.
Safety Chains
You should always attach chains between your vehicle
and your trailer. Cross the safety chains under the
tongue of the trailer to help prevent the tongue from
contacting the road if it becomes separated from
the hitch. Instructions about safety chains may be
provided by the hitch manufacturer or by the trailer
manufacturer. For trailers up to 3,500 lbs. (1 589 kg) you
may attach the safety chains to the attaching points
on the bumper. For heavier trailers, follow the trailer or
hitch manufacturer’s recommendation for attaching
safety chains. Always leave just enough slack so you
can turn with your rig. Never allow safety chains to drag
on the ground.
Trailer Brakes
If your trailer weighs more than 1,000 lbs. (450 kg)
loaded, then it needs its own brake–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:
•The trailer parts can withstand 3,000 psi
(20 650 kPa) of pressure.
•The trailer’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 far, then make the brake
fluid tap at the port on the master cylinder that
sends fluid to the rear brakes. But don’t use copper
tubing for this. If you do, it will bend and finally break off.
Use steel brake tubing.
Driving with a Trailer
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.
4-60

And always keep in mind that the vehicle you are
driving is now a good deal longer and not nearly as
responsive as your vehicle is by itself.
Before you start, check all trailer hitch, all parts 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 would when driving your vehicle without a trailer.
This can help you avoid situations that require
heavy braking and sudden turns.
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.
4-61

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.
Driving On Grades
Reduce speed and shift to a lower gear before 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.
You should use THIRD (3) when towing a trailer.
Operating your vehicle in THIRD (3) 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 turn your
engine off immediately 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 (P) (or
the manual transmission out of gear and the parking
brake applied) for a few minutes before turning the
engine off. If you do get the overheat warning,
seeEngine Overheating on page 5-26.
Parking on Hills
{CAUTION:
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. Apply your regular brakes, but don’t shift into
PARK (P) yet, or into gear for a manual
transmission. When parking uphill, turn your wheels
away from the curb. When parking downhill, turn
your wheels into the curb.
2. Have someone place chocks under the
trailer wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4-62