CHEVROLET SILVERADO 2007 1.G Owners Manual

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. If you
have a lot of options, equipment, passengers
or cargo in your vehicle, it will reduce the tongue
weight your vehicle can carry, which will also
reduce the trailer weight your vehicle can tow.
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. SeeLoading
Your Vehicle on page 427for more information
about your vehicle’s maximum load capacity.The trailer tongue weight (A) should be 10 percent
to 15 percent of the total loaded trailer weight,
up to a maximum of 600 lbs (272 kg) for the
1500 or 2500 series, and up to a maximum of
750 lbs (340 kg) for the 2500 HD or 3500 series
with a weight carrying hitch. The trailer tongue
weight (A) should be 10 percent to 15 percent of
the total loaded trailer weight, up to a maximum
of 1,000 lbs (453 kg) for the 1500 series and up to
a maximum of 1,500 lbs (680 kg) for the 2500,
2500 HD or 3500 series with a weight distributing
hitch.
461

Fifth wheel or gooseneck kingpin weight should be
15 to 25 percent of the trailer weight up to the
maximum amount specied in the trailering chart
for your vehicle. See “Weight of the Trailer”,
and “Fifth-Wheel and Gooseneck Trailering”
in this section.
Do not exceed the maximum allowable tongue
weight for your vehicle. Choose the shortest hitch
extension that will position the hitch ball closest
to the vehicle. This will help reduce the effect
of trailer tongue weight on the rear axle.
After you have loaded the trailer, weigh the trailer
and then the tongue separately, to see if the
weights are proper. If they are not, you may be
able to get them right by moving some items
around in the trailer.
Trailering may be limited by the vehicle’s ability to
carry tongue weight. Tongue weight cannot cause
the vehicle to exceed the GVWR (Gross Vehicle
Weight Rating) or the RGAWR (Rear Gross Axle
Weight Rating). The effect of additional weight
may reduce your trailering capacity more than the
total of the additional weight.Consider the following example:
A vehicle model base weight is 5,500 lbs
(2 495 kg); 2,800 lbs (1 270 kg) at the front axle
and 2,700 lbs (1 225 kg) at the rear axle. It has a
GVWR of 7,200 lbs (3 266 kg), a RGAWR of
4,000 lbs (1 814 kg) and a GCWR (Gross
Combination Weight Rating) of 14,000 lbs
(6 350 kg). The trailer rating should be:
You can expect tongue weight to be at least
10 percent of trailer weight (850 lbs (386 kg)) and
because the weight is applied well behind the
rear axle, the effect on the rear axle will be greater
than just the weight itself, as much as 1.5 times
as much. The weight at the rear axle could
be 850 lbs (386 kg) X 1.5 = 1,275 lbs (578 kg).
462

Since the rear axle already weighs 2,700 lbs
(1 225 kg), adding 1,275 lbs (578 kg) brings the
total to 3,975 lbs (1 803 kg). This is very close to,
but within the limit for RGAWR as well. The vehicle
is set to trailer up to 8,500 lbs (3 856 kg).
But let’s say your specic vehicle is equipped with
some of the latest options and you have a front
seat passenger and two rear seat passengers with
some luggage and gear in the vehicle as well.
You may add 300 lbs (136 kg) to the front axle
weight and 400 lbs (181 kg) to the rear axle
weight. Your vehicle now weighs:
Weight is still below 7,200 lbs (3 266 kg) and you
may think that you should subtract 700 additional
pounds (318 kg) from your trailering capacity
to stay within GCWR limits. Your maximum
trailer would only be 7,800 lbs (3 538 kg).You may go further and think you must limit
tongue weight to less than 1,000 lbs (454 kg) to
avoid exceeding GVWR. But, you must still
consider the effect on the rear axle. Because your
rear axle now weighs 3,100 lbs (1 406 kg), you
can only put 900 lbs (408 kg) on the rear axle
without exceeding RGAWR. The effect of tongue
weight is about 1.5 times the actual weight.
Dividing the 900 lbs (408 kg) by 1.5 leaves you
with being able to handle only 600 lbs (272 kg) of
tongue weight. Since tongue weight is usually
at least 10 percent of total loaded trailer weight,
you can expect that the largest trailer your vehicle
can properly handle is 6,000 lbs (2 721 kg).
It is important that you make sure your vehicle
does not exceed any of its ratings — GCWR,
GVWR, RGAWR, Maximum Trailer Rating
or Tongue Weight. The only way to be sure you
are not exceeding any of these ratings is to weigh
your vehicle and trailer.
463

Total Weight on Your Vehicle’s Tires
Be sure your vehicle’s tires are inated to the
upper limit for cold tires. You’ll nd these numbers
on the Certication label at the rear edge of the
driver’s door or see Loading Your Vehicle for more
information. Then be sure you don’t go over the
GVW limit for your vehicle, or the GAWR, including
the weight of the trailer tongue. If you use a
weight distributing hitch, make sure you don’t go
over the rear axle limit before you apply the weight
distribution spring bars.
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.
Weight-Distributing Hitches and Weight
Carrying Hitches
A:Body to Ground Distance
B:Front of Vehicle
When using a weight-distributing hitch, the hitch
must be adjusted so the distance (A) remains
the same both before and after coupling the trailer
to the tow vehicle.
464

If you use a step-bumper hitch, the bumper could
be damaged in sharp turns. Make sure there is
ample room when turning to avoid contact between
the trailer and the bumper.
If you will 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.
Always use a sway control if the trailer will weigh
more than these limits. You can ask a hitch
dealer about sway controls.Fifth Wheel and Gooseneck Trailering
Fifth wheel and gooseneck trailers can be used
with many pickup models. These trailers place a
larger percentage of the weight (kingpin weight)
on the tow vehicle than conventional trailers.
Make sure this weight does not cause the vehicle
to exceed GAWR or GVWR.
Fifth wheel or gooseneck kingpin weight should be
15 to 25 percent of the trailer weight up to the
maximum amount specied in the trailering chart
for your vehicle. See “Weight of the Trailer” in
this section for more information.
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.
465

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.
466

Integrated Trailer Brake Control System
Your vehicle may have
an Integrated Trailer
Brake Control (ITBC)
system for electric trailer
brakes.
This symbol is located on the Trailer Brake
Control Panel on vehicles with an Integrated
Trailer Brake Control System. The power output to
the trailer brakes is based on the amount of
brake pressure being applied by your vehicle’s
brake system. This available power output to the
trailer brakes can be adjusted to a wide range
of trailering situations.The ITBC system is integrated with your
vehicle’s brake, anti-lock brake and StabiliTrak
®
(if equipped) systems. In trailering conditions
that cause your vehicle’s anti-lock brake or
StabiliTrak
®systems to activate, power sent to the
trailer’s brakes will be automatically adjusted to
minimize trailer wheel lock-up. This does not imply
that your trailer has the StabiliTrak
®system.
If your vehicle’s brake, anti-lock brake or
StabiliTrak
®systems are not functioning properly,
your ITBC system may not be fully functional
or may not function at all. Make sure all of these
systems are fully operational to ensure full
functionality of the ITBC system.
The ITBC system is powered through your
vehicle’s electrical system. Turning the ignition off
will also turn off the ITBC system. The ITBC
system is fully functional only when the ignition is
in ON or in RUN.
467

The ITBC system can only be used with trailers
with electric brakes.
{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.
468

Trailer Brake Control Panel
A. Manual Trailer Brake Apply Lever
B. Trailer Gain Adjustment ButtonsThe ITBC system has a control panel located on
the instrument panel to the left of the steering
column. SeeInstrument Panel Overview
(Base/Uplevel version) on page 208orInstrument
Panel Overview (Premium version) on page 211
for more information on location. The control panel
allows you to adjust the amount of output,
referred to as trailer gain, available to the electric
trailer brakes and allows you to manually apply
the trailer brakes. The Trailer Brake Control Panel
is used along with the Trailer Brake Display
Page on the DIC to adjust and display power
output to the trailer brakes.
469

Trailer Brake DIC Display Page
The ITBC system displays messages into the
vehicle’s Driver Information Center (DIC). SeeDIC
Warnings and Messages on page 281for more
information.
The display page indicates Trailer Gain setting,
power output to the electric trailer brakes,
trailer connection and system operational status.
A. Trailer Gain Setting
B. Power Output to Trailer Brakes
C. No trailer with electric brakes connected or
fault presentThe Trailer Brake Display Page can be displayed
by performing any of the following actions:Scrolling through the DIC menu pages using
the odometer trip stem or the DIC Vehicle
Information button (if equipped).
Pressing a Trailer Gain button – If the Trailer
Brake Display Page is not currently displayed,
pressing a Trailer Gain button will rst recall the
current Trailer Gain setting. After the Trailer
Brake Display Page is displayed, subsequent
depressions of the gain buttons will then cause
the Trailer Gain setting to change.
Activating the Manual Trailer Brake Apply lever
Connecting a trailer equipped with electric
trailer brakes
All DIC warning and service messages must
rst be acknowledged by the driver before
the Trailer Brake Display Page can be displayed
and Trailer Gain can be adjusted.
470