tow GMC SIERRA 2009 Repair Manual

The Tire and Loading Information label also shows
the size of the original equipment tires (C) and the
recommended cold tire ination pressures (D).
For more information on tires and ination see
Tires on page 5-65andInflation - Tire Pressure
on page 5-73.
There is also important loading information on the
vehicle Certication/Tire label. It tells you the Gross
Vehicle Weight Rating (GVWR) and the Gross Axle
Weight Rating (GAWR) for the front and rear axles.
See “Certication/Tire Label” later in this section.
Steps for Determining Correct Load Limit
1.Locate the statement “The combined weight
of occupants and cargo should never exceed
XXX kg or XXX lbs” on your vehicle’s 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 kg or XXX lbs.
4.The resulting gure equals the available
amount of cargo and luggage load capacity.
For example, if the “XXX” amount equals
1400 lbs and there will be ve 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 4-51for important information
on towing a trailer, towing safety rules and
trailering tips.
4-33

For example, adding a 700 lb (318 kg) snow plow
actually adds more than 700 lbs (318 kg) to the front
axle. Using the formula, if the snow plow is 4 ft (122 cm)
in front of the front axle and the wheel base is 10 ft
(305 cm), then:
W = 700 lb (318 kg)
A = 4 ft (122 cm)
W.B. = 10 ft (305 cm)
(W x (A + W.B.))/W.B. = (700 x (4 + 10))/10 = 980 lbs
(445 kg)
So, if your truck’s front axle reserve capacity is more
than 980 lbs (445 kg), you could add the snow plow
without exceeding the front GAWR.
You can add heavier equipment on the front of the
vehicle if you compensate for it by carrying fewer
passengers, less cargo, or by positioning cargo towards
the rear. This has the effect of reducing the load on the
front. However, the front GAWR, rear GAWR, and the
Gross Vehicle Weight Rating (GVWR) must never be
exceeded.
{CAUTION:
On some vehicles that have certain front mounted
equipment, such as a snow plow, it may be possible
to load the front axle to the front gross axle weight
rating (GAWR) but not have enough weight on the
rear axle to have proper braking performance.
If your brakes can not work properly, you could
have a crash. To help your brakes work properly
when a snow plow is installed, always follow
the snow plow manufacturer or installer’s
recommendation for rear ballast to ensure a proper
front and rear weight distribution ratio, even though
the actual front weight may be less than the front
GAWR, and the total vehicle weight is less than the
gross vehicle weight rating (GVWR). Maintaining a
proper front and rear weight distribution ratio is
necessary to provide proper braking performance.
Total vehicle reserve capacity is the difference between
your GVWR and the weight of your truck with full fuel
and passengers. It is the amount of weight you can
add to your vehicle before reaching your GVWR.
4-41

Pickup Conversion to Chassis Cab
We are aware that some vehicle owners might consider
having the pickup box removed and a commercial or
recreational body installed. Owners should be aware
that, as manufactured, there are differences between a
chassis cab and a pickup with the box removed which
could affect vehicle safety. The components necessary
to adapt a pickup to permit its safe use with a specialized
body should be installed by the body builder.
Towing
Towing Your Vehicle
To avoid damage, the disabled vehicle should be towed
with all four wheels off the ground. Consult your dealer/
retailer or a professional towing service if the disabled
vehicle must be towed. SeeRoadside Assistance
Program on page 7-7.
To tow the 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 the vehicle
behind another vehicle – such as behind a motorhome.
The two most common types of recreational vehicle
towing are known as dinghy towing and dolly towing.
Dinghy towing is towing the vehicle with all four wheels
on the ground. Dolly towing is towing the vehicle
with two wheels on the ground and two wheels up
on a device known as a dolly.
Here are some important things to consider before
recreational vehicle towing:
What is the towing capacity of the towing vehicle?
Be sure to read the tow vehicle manufacturer’s
recommendations.
What is the distance that will be travelled? Some
vehicles have restrictions on how far and how
long they can tow.
Is the proper towing equipment going to be used?
See your dealer/retailer or trailering professional for
additional advice and equipment recommendations.
Is the vehicle ready to be towed? Just as preparing
the vehicle for a long trip, make sure the vehicle is
prepared to be towed. SeeBefore Leaving on a
Long Trip on page 4-26.
4-45

Dinghy Towing
Two-Wheel-Drive Vehicles
Notice:If the vehicle is towed with all four wheels
on the ground, the drivetrain components could
be damaged. The repairs would not be covered by
the vehicle warranty. Do not tow the vehicle with
all four wheels on the ground.
Two-wheel-drive vehicles should not be towed
with all four wheels on the ground. Two-wheel-drive
transmissions have no provisions for internal lubrication
while being towed.
Four-Wheel-Drive Vehicles
Use the following procedure to dinghy tow a
four-wheel-drive vehicle:
1. Position the vehicle being towed behind the tow
vehicle and shift the transmission to P (Park).
2. Turn the engine off and rmly set the parking brake.
3. Securely attach the vehicle being towed to the
tow vehicle.
4-46

{CAUTION:
Shifting a four-wheel-drive vehicle’s transfer case
into N (Neutral) can cause the vehicle to roll even
if the transmission is in P (Park). The driver or
others could be injured. Make sure the parking
brake is rmly set before the transfer case is
shifted to N (Neutral).
4. Shift the transfer case to N (Neutral). See “Shifting
into Neutral” underFour-Wheel Drive on page 2-37
for the proper procedure to select the Neutral
position for the vehicle.
5. Release the parking brake only after the vehicle
being towed is rmly attached to the towing vehicle.
6. Turn the ignition to LOCK/OFF and remove the
key — the steering wheel will still turn.
After towing, see “Shifting Out of Neutral” under
Four-Wheel Drive on page 2-37for the proper procedure
to take the vehicle out of the Neutral position.
Dolly Towing
Front Towing (Front Wheels Off
the Ground)
Two-Wheel-Drive Vehicles
Notice:If a two-wheel-drive vehicle is towed with
the rear wheels on the ground, the transmission
could be damaged. The repairs would not be
covered by the vehicle warranty. Never tow the
vehicle with the rear wheels on the ground.
Two-wheel-drive vehicles should not be towed
with the rear wheels on the ground. Two-wheel-drive
transmissions have no provisions for internal lubrication
while being towed.
4-47

To dolly tow a two-wheel-drive vehicle, the vehicle
must be towed with the rear wheels on the dolly.
See “Rear Towing (Rear Wheels Off the Ground)”
later in this section for more information.
Four-Wheel-Drive Vehicles
Use the following procedure to dolly tow a
four-wheel-drive vehicle from the front:
1. Attach the dolly to the tow vehicle following the
dolly manufacturer’s instructions.
2. Drive the front wheels onto the dolly.
3. Shift the transmission to P (Park).
4. Firmly set the parking brake.
{CAUTION:
Shifting a four-wheel-drive vehicle’s transfer case
into N (Neutral) can cause the vehicle to roll even
if the transmission is in P (Park). The driver or
others could be injured. Make sure the parking
brake is rmly set before the transfer case is
shifted to N (Neutral).
5. Use an adequate clamping device designed for
towing to ensure that the front wheels are locked
into the straight position.
6. Secure the vehicle to the dolly following the
manufacturer’s instructions.
7. Shift the transfer case to N (Neutral). See “Shifting
into Neutral” underFour-Wheel Drive on page 2-37
for the proper procedure to select the neutral position
for the vehicle.
8. Release the parking brake only after the vehicle
being towed is rmly attached to the towing vehicle.
9. Turn the ignition to LOCK/OFF.
After towing, see “Shifting Out of Neutral” under
Four-Wheel Drive on page 2-37.
4-48

Rear Towing (Rear Wheels Off
the Ground)Two-Wheel-Drive Vehicles
Use the following procedure to dolly tow a
two-wheel-drive vehicle from the rear:
1. Attach the dolly to the tow vehicle following the
dolly manufacturer’s instructions.
2. Drive the rear wheels onto the dolly.
3. Firmly set the parking brake. SeeParking Brake on
page 2-50.
4. Put the transmission in P (Park).
5. Secure the vehicle to the dolly following the
manufacturer’s instructions.
6. Use an adequate clamping device designed for
towing to ensure that the front wheels are locked
into the straight position.
7. Turn the ignition to LOCK/OFF.
4-49

Four-Wheel-Drive Vehicles
Use the following procedure to dolly tow a
four-wheel-drive vehicle from the rear:
1. Attach the dolly to the tow vehicle following the
dolly manufacturer’s instructions.
2. Drive the rear wheels onto the dolly.
3. Firmly set the parking brake. SeeParking Brake on
page 2-50.
4. Put the transmission in P (Park).
5. Secure the vehicle to the dolly following the
manufacturer’s instructions.
6. Use an adequate clamping device designed for
towing to ensure that the front wheels are locked
into the straight position.{CAUTION:
Shifting a four-wheel-drive vehicle’s transfer case
into N (Neutral) can cause the vehicle to roll even
if the transmission is in P (Park). The driver or
others could be injured. Make sure the parking
brake is rmly set before the transfer case is
shifted to N (Neutral).
7. Shift the transfer case to N (Neutral). See “Shifting
into Neutral” underFour-Wheel Drive on page 2-37
for the proper procedure to select the neutral
position for the vehicle.
8. Turn the ignition to LOCK/OFF.
After towing, see “Shifting Out of Neutral” under
Four-Wheel Drive on page 2-37.
4-50

Towing a Trailer
If the vehicle has a diesel engine, see the DURAMAX®
Diesel manual for more information.
Do not tow a trailer during break-in. SeeNew Vehicle
Break-In on page 2-22for more information.
{CAUTION:
The driver can lose control when pulling a trailer if
the correct equipment is not used or the vehicle is
not driven properly. For example, if the trailer is too
heavy, the brakes may not work well or even at all.
The driver and passengers could be seriously
injured. The vehicle may also be damaged; the
resulting repairs would not be covered by the
vehicle warranty. Pull a trailer only if all the steps in
this section have been followed. Ask your dealer/
retailer for advice and information about towing a
trailer with the vehicle.Notice:Pulling a trailer improperly can damage
the vehicle and result in costly repairs not covered
by the vehicle warranty. To pull a trailer correctly,
follow the advice in this section and see your
dealer/retailer for important information about
towing a trailer with the vehicle.
To identify the trailering capacity of the vehicle, read
the information in “Weight of the Trailer” that appears
later in this section.
Trailering is different than just driving the vehicle by
itself. Trailering means changes in handling, acceleration,
braking, durability and fuel economy. Successful, safe
trailering takes correct equipment, and it has to be used
properly.
The following information has 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 pulling a trailer.
4-51

Pulling A Trailer
Here are some important points:
There are many different laws, including speed limit
restrictions, having to do with trailering. Make sure
the rig will be legal, not only where you live but
also where you will 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.
Do not tow a trailer at all during the rst 500 miles
(800 km) the new vehicle is driven. The engine,
axle or other parts could be damaged.
Then, during the rst 500 miles (800 km) that a
trailer is towed, do not drive over 50 mph (80 km/h)
and do not make starts at full throttle. This helps
the engine and other parts of the vehicle wear in
at the heavier loads.
Vehicles can tow in D (Drive). Shift the transmission
to a lower gear if the transmission shifts too often
under heavy loads and/or hilly conditions.Three important considerations have to do with weight:
The weight of the trailer
The weight of the trailer tongue
And the weight on the vehicle’s tires
Weight of the Trailer
How heavy can a trailer safely be?
It depends on how the rig is used. For example, speed,
altitude, road grades, outside temperature and how much
the vehicle is used to pull a trailer are all important. It can
depend on any special equipment on the vehicle, and
the amount of tongue weight the vehicle can carry.
See “Weight of the Trailer Tongue” later in this section
for more information.
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.
Use the following chart to determine how much the
vehicle can weigh, based upon the vehicle model
and options.
Weights listed apply for conventional trailers and
fth-wheel trailers unless otherwise noted.
4-52