towing GMC SIERRA 2008 Owner's Guide

To prevent transmission wear, wait until the wheels stop
spinning before shifting gears. Release the accelerator
pedal while you shift, and press lightly on the accelerator
pedal when the transmission is in gear. By slowly
spinning the wheels in the forward and reverse
directions, you will cause a rocking motion that could
free your vehicle. If that does not get your vehicle
out after a few tries, it might need to be towed out.
Or, you can use recovery hooks, if your vehicle
has them. If your vehicle does need to be towed out,
seeTowing Your Vehicle on page 4-50.
Recovery Hooks
{CAUTION:
These hooks, when used, are under a lot of
force. Always pull the vehicle straight out.
Never pull on the hooks at a sideways angle.
The hooks could break off and you or others
could be injured from the chain or cable
snapping back.Notice:Never use recovery hooks to tow the
vehicle. Your vehicle could be damaged and it would
not be covered by warranty.
For vehicles with recovery hooks at the front of the
vehicle, you can use them if you are stuck off-road and
need to be pulled to some place where you can
continue driving.
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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 5-66andInflation - Tire Pressure on
page 5-74.
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 4-55for important
information on towing a trailer, towing safety
rules and trailering tips.
4-37

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
Consult your dealer/retailer or a professional towing
service if you need to have your disabled vehicle towed.
SeeRoadside Assistance Program on page 7-7.
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
will 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”.
With the proper preparation and equipment, many
vehicles can be towed in these ways. See “Dinghy
Towing” and “Dolly Towing” following.
Here are some important things to consider before you
do recreational vehicle towing:
What’s the towing capacity of the towing vehicle?
Be sure you read the tow vehicle manufacturer’s
recommendations.
How far will you tow? Some vehicles have
restrictions on how far and how long they can tow.
Do you have the proper towing equipment?
See your dealer or trailering professional for
additional advice and equipment recommendations.
Is your vehicle ready to be towed? Just as you
would prepare your vehicle for a long trip, you’ll
want to make sure your vehicle is prepared to be
towed. SeeBefore Leaving on a Long Trip on
page 4-29.
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Dinghy Towing
Two-Wheel-Drive Vehicles
Notice:If you tow your vehicle with all four wheels
on the ground, the drivetrain components could
be damaged. The repairs would not be covered by
your warranty. Do not tow your 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 tow your vehicle:
1. Shift the transmission to PARK (P).
2. Turn the engine off, but leave the ignition on.
3. Firmly set the parking brake.
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4. Securely attach the vehicle being towed to the tow
vehicle.
{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).
You or others could be injured. Make sure the
parking brake is rmly set before you shift the
transfer case to NEUTRAL.
5. Shift the transfer case to NEUTRAL. See
Four-Wheel Drive on page 2-36for the proper
procedure to select the neutral position for
your vehicle.
6. Release the parking brake only after the vehicle
being towed is rmly attached to the towing
vehicle.
7. Turn the ignition to LOCK/OFF.
Dolly Towing
Front Towing (Front Wheels Off the
Ground)
Two-Wheel-Drive Vehicles
Notice:If you tow a two-wheel-drive vehicle with
the rear wheels on the ground, the transmission
could be damaged. The repairs would not be
covered by your warranty. Never tow your 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.
To dolly tow a two-wheel-drive vehicle, you must tow
the vehicle with the rear wheels on the dolly. See “Rear
Towing (Rear Wheels Off the Ground)” later in this
section for more information.
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Four-Wheel-Drive Vehicles
Use the following procedure to tow your vehicle:
1. Drive the vehicle up onto the tow dolly.
2. Shift the transmission to PARK (P).
3. Turn the engine off, but leave the ignition on.
4. Firmly set the parking brake.
5. Securely attach the vehicle being towed to the
tow dolly.
{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).
You or others could be injured. Make sure the
parking brake is rmly set before you shift the
transfer case to NEUTRAL.
6. Shift the transfer case to NEUTRAL. See
Four-Wheel Drive on page 2-36for the proper
procedure to select the neutral position for
your vehicle.
7. Release the parking brake only after the vehicle
being towed is rmly attached to the towing
vehicle.
8. Turn the ignition to LOCK/OFF.
4-53

Rear Towing (Rear Wheels Off the
Ground)
Two-Wheel-Drive Vehicles
Use the following procedure to tow your vehicle from
the rear:
1. Drive the vehicle onto the dolly.
2. Firmly set the parking brake. SeeParking Brake on
page 2-49.
3. Put the transmission in PARK (P).
4. Follow the dolly manufacturer’s instructions to attach
and secure the vehicle being towed to the dolly and
then the loaded dolly to the tow vehicle. Make sure
the wheels are straight before towing.
Use an adequate clamping device to ensure that
the front wheels are locked into the straight position.
5. Release the parking brake only after the vehicle
being towed is rmly attached to the tow vehicle.
6. Turn the ignition to LOCK/OFF.
Four-Wheel-Drive Vehicles
Use the following procedure to tow your vehicle from
the rear:
1. Drive the vehicle onto the dolly.
2. Firmly set the parking brake. SeeParking Brake on
page 2-49.
3. Put the transmission in PARK (P).
4. Follow the dolly manufacturer’s instructions to attach
and secure the vehicle being towed to the dolly and
then the loaded dolly to the tow vehicle.
Use an adequate clamping device to ensure that
the front wheels are locked into the straight position.
{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).
You or others could be injured. Make sure the
parking brake is rmly set before you shift the
transfer case to NEUTRAL.
5. Shift the transfer case to NEUTRAL. See
Four-Wheel Drive on page 2-36.
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6. Release the parking brake only after the vehicle
being towed is rmly attached to the tow vehicle.
7. Turn the ignition to LOCK/OFF.
Towing a Trailer
If your 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:
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 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.
To identify the trailering capacity of your vehicle, you
should read the information in “Weight of the Trailer” that
appears later in this section.
Trailering is different than just driving your vehicle by
itself. Trailering means changes in acceleration, braking,
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.
4-55

The hitch should be located in the pickup bed so that it’s
centerline is over or slightly in front of the rear axle. Take
care that it is not so far forward that it will contact the back
of the cab in sharp turns. This is especially important for
short box pickups. Trailer pin box extensions and sliding
fth wheel hitch assemblies can help this condition. There
should be at least six inches of clearance between the top
of the pickup box and the bottom of the trailer shelf that
extends over the box.
Make sure the hitch is attached to the tow vehicle frame
rails. Do not use the pickup box for support.
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. If you
are towing a trailer up to 5,000 lbs (2 271 kg) with a
factory-installed step bumper, you may attach the safety
chains to the attaching points on the bumper. If you are
towing a trailer up to your vehicle’s trailer rating limit you
may attach the safety chains to the attaching point on the
hitch platform. If you are towing with an aftermarket hitch
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 2,000 lbs (900 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.
If your vehicle is equipped with StabiliTrak
®, your trailer
cannot tap into the vehicle’s hydraulic brake system.
Your trailer 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 uid 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, make the brake tap at
the port on the master cylinder that sends the uid
to the rear brakes. But don’t use copper tubing for this.
If you do, it will bend and nally break off. Use steel
brake tubing.
4-77

{CAUTION:
Connecting a trailer that is not compatible with
the ITBC system may result in reduced or
complete loss of trailer braking. There may be
an increase in stopping distance or trailer
instability which could result in personal injury
or damage to your vehicle, trailer, or other
property. An aftermarket controller may be
available for use with trailers with surge, air or
electric-over-hydraulic trailer brake systems.
To determine the type of brakes on your trailer
and the availability of controllers, check with
your trailer manufacturer or dealer.When trailering, make sure of the following:
The ITBC system is used only with trailers that are
equipped with electric brakes.
All applicable local and federal laws and regulations
are followed.
All electrical and mechanical connections to the
trailer are made correctly.
The trailer’s brakes are in proper working condition.
The trailer and vehicle are properly loaded for
the towing condition.
The ITBC system is a factory installed item.
Out-of-factory installation of this system should not be
attempted. GM is not responsible for warranty or
performance of the system resulting from out-of-factory
installation.
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