GMC SONOMA 2002 Owner's Manual

4-43
When towing your vehicle, turn the ignition to OFF. To
prevent your battery from draining while towing,
remove the RDO BATT and CLSTR fuses from the
instrument panel fuse block. Be sure to replace the fuse
when you reach your destination. See ªFuses and Circuit
Breakersº in the Index.
Be sure to use the proper towing equipment designed for
recreational vehicle towing. Follow the instructions for
the towing equipment.
CAUTION:
Shifting a four-wheel-drive vehicle's transfer
case into NEUTRAL can cause your vehicle to
roll even if the transmission is in Park (P), for an
automatic transmission, or if your vehicle is in
gear, for a manual transmission. You or others
could be injured. Make sure the parking brake is
firmly set before you shift the transfer case to
NEUTRAL.
Dolly Towing
(Two-Wheel Drive Models Only)
Your vehicle should not be towed with all four wheels
on the ground. Your transmission has no provision for
internal lubrication while being towed. To properly tow
your vehicle, it should be placed on a platform trailer
with all four wheels off the ground. Towing with all four
wheels on the ground should be avoided.

4-44
In rare cases when it's unavoidable and your vehicle
must be towed with all four wheels on the ground, the
propeller shaft to axle yoke orientation should be
marked and the propeller shaft removed following the
applicable service manual removal/installation
procedure. See ªService and Owner Publicationsº in
the Index.
Dust or dirt can enter the back of the transmission
through the opening created by removing the propeller
shaft if proper protection is not provided. Also, check
the transmission fluid level before driving the vehicle.
Use the following steps to dolly tow your vehicle:

Put the front wheels on a dolly.

Put the vehicle in PARK (P).

Set the parking brake and then remove the key.

Disconnect the propshaft as described above.

Clamp the steering wheel in a straight
-ahead position
with a clamping device designed for towing.

Release the parking brake.Be sure to use the proper towing equipment designed for
recreational vehicle towing. Follow the instructions for
the towing equipment.
CAUTION:
Shifting a four-wheel-drive vehicle's transfer
case into NEUTRAL can cause your vehicle to
roll even if the transmission is in PARK (P), for
an automatic transmission, or if your vehicle is in
gear, for a manual transmission. You or others
could be injured. Make sure the parking brake is
firmly set before you shift the transfer case into
NEUTRAL.

4-45
Loading Your Vehicle
The Certification/Tire label is found on the driver's door
edge, above the door latch. The label shows the size of
your original tires and the inflation pressures needed to
obtain the gross weight capacity of your vehicle. This is
called the Gross Vehicle Weight Rating (GVWR). The
GVWR includes the weight of the vehicle, all occupants,
fuel, cargo and trailer tongue weight, if pulling a trailer.The Certification/Tire label also tells you the maximum
weights for the front and rear axles, called Gross Axle
Weight Rating (GAWR). To find out the actual loads on
your front and rear axles, you need to go to a weigh
station and weigh your vehicle. Your dealer can help
you with this. Be sure to spread out your load equally on
both sides of the centerline.
Never exceed the GVWR for your vehicle, or the
GAWR for either the front or rear axle.
And, if you do have a heavy load, you should spread
it out.
Similar appearing vehicles may have different GVWRs
and payloads. Please note the Certification/Tire label on
your truck or consult your dealer for additional details.CAUTION:
In the case of a sudden stop or collision, things
carried in the bed of your truck could shift
forward and come into the passenger area,
injuring you and others. If you put things in the
bed of your truck, you should make sure they are
properly secured.

4-46
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.
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.
If you put things inside your vehicle -- like suitcases,
tools, packages, or anything else
-- they will go as fast
as the vehicle goes. If you have to stop or turn quickly,
or if there is a crash, they'll keep going.
CAUTION:
Things you put inside your vehicle can strike
and injure people in a sudden stop or turn, or
in a crash.

Put things in the cargo area of your vehicle.
Try to spread the weight evenly.

Never stack heavier things, like suitcases,
inside the vehicle so that some of them are
above the tops of the seats.

Don't leave an unsecured child restraint in
your vehicle.

When you carry something inside the
vehicle, secure it whenever you can.
There's also important loading information for off-road
driving in this manual. See ªLoading Your Vehicle for
Off
-Road Drivingº in the Index.

4-47 Payload
The payload capacity is shown on the Certification/Tire
label. This is the maximum load capacity that your
vehicle can carry. If you are using E85 ethanol fuel the
maximum payload should not exceed 1000 lbs (454 kg).
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.
Remember not to exceed the Gross Axle Weight Rating
(GAWR) of the front or rear axle. See ªLoading Your
Vehicleº in the Index.
Two-Tiered Loading
By positioning four 2, x 6, wooden planks across the
width of the pickup box, you can create an upper load
platform. The planks must be inserted in the pickup box
depressions. The length of the planks must allow for at
least a 3/4 inch (2 cm) bearing surface on each end of
the plank.
When using this upper load platform, be sure the load is
securely tied down to prevent it from shifting. The
load's center of gravity should be positioned in a zone
over the rear axle.Any load that extends beyond the vehicle's taillamp area
must be properly marked according to local laws and
regulations.
Remember not to exceed the Gross Axle Weight Rating
(GAWR) of the rear axle. See ªLoading Your Vehicleº
in the Index.
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.
NOTICE:
Your warranty doesn't cover parts or
components that fail because of overloading.
Remember not to exceed the Gross Axle Weight Rating
(GAWR) of the rear axle. See ªLoading Your Vehicleº
in the Index.

4-48 Truck-Camper Loading Information
The Truck-Camper Loading label is located on the
passenger's door near the latch. It will tell you if your
vehicle can carry a slide
-in camper, how much of a load
your vehicle can carry, and how to correctly spread out
your load. Also, it will help you match the right slide
-in
camper to your vehicle.
When the truck is used to carry a slide
-in camper, the
total cargo load of the truck consists of the
manufacturer's camper weight figure, the weight of
installed additional camper equipment not included in
the manufacturer's camper weight figure, the weight of
camper cargo, and the weight of passengers in the
camper. The total cargo load should not exceed the
truck's cargo weight rating and the camper's center of
gravity should fall within the truck's recommended
center of gravity zone when installed.
The Cargo Weight Rating (CWR) is the maximum
weight of the load your vehicle can carry. It doesn't
include the weight of the people inside. But, you can
figure about 150 lbs. (68 kg) for each seating position.
The total cargo load must not be more than your
vehicle's CWR.Refer to the Truck
-Camper Loading Information Label
on the passenger's door for dimensions A and B as
shown in the following illustration.
Use the rear edge of the load floor for measurement
purposes. The recommended location for the cargo
center of gravity for the Cargo Weight Rating (C) is
the point where the mass of a body is concentrated
and, if suspended at that point, would balance the
front and rear.

4-49
Here is an example of proper truck and camper match:
A. Camper Center of Gravity
B. Recommended Center of Gravity Location Zone
The camper's center of gravity should fall within the
center of gravity zone for your vehicle's cargo load.
Campers can only be installed in a long box pickup.
Check your Truck
-Camper Loading Label on the
passenger's door to determine if your vehicle can carry a
slide
-in camper.
You must weigh any accessories, trailer hitches or other
equipment you add to your vehicle. Then, subtract this
extra weight from the CWR. This extra weight may
shorten the center of gravity zone for your vehicle. Your
dealer can help you with this.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 ªConsumer Information,
Truck
-Camper Loading.º

4-50 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, see ªTowing a Trailerº 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 ªCustomer Assistanceº in
the Index.
Towing a Trailer
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.

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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. Additional rear axle
maintenance is required for a vehicle used to tow
a trailer. See ªScheduled Maintenance Servicesº
in the Index.
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 ªWeight of the
Trailerº 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, 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.

4-52 If You Do Decide To Pull A Trailer
If you do, here are some important points:

If you have the 2200 L4 (Code 5) engine, use regular
gasoline (without ethanol) when pulling a trailer. See
ªFuelº in the Index.

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 3,500 lbs. (1 589 kg). You should always use
a sway control if your trailer will weigh more than
3,500 lbs. (1 589 kg). You can ask a hitch dealer
about sway controls.

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.
If you have an automatic transmission, tow in
DRIVE (D). 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.