weight GMC SIERRA CLASSIC 2007 Service Manual

K-3500 Extended Cab (4WD)*Axle Ratio Maximum Trailer Weight GCWR
6.6L V8 Dual Rear Wheel
(Manual)3.73 14,800 lbs (6 713 kg) 22,000 lbs (9 979 kg)
6.6L V8 Dual Rear Wheel
(Automatic)3.73 16,300 lbs (7 394 kg) 23,500 lbs (10 659 kg)
*Fifth-wheel or gooseneck kingpin weight should be 15 percent to 25 percent of trailer weight up to 3,500 lbs
(1 587 kg) maximum.
*Trailer rating limited to 12,000 lbs (5 443 kg) with weight distributing hitch.
K-3500 Crew Cab (4WD)* Axle Ratio Maximum Trailer Weight GCWR
6000 V8 Single Rear Wheel 4.10 9,400 lbs (4 264 kg) 16,000 lbs (7 264 kg)
6000 V8 Dual Rear Wheel 4.10 9,200 lbs (4 173 kg) 16,000 lbs (7 264 kg)
8100 V8 Single Rear Wheel 4.10 15,000 lbs (6 804 kg) 22,000 lbs (9 979 kg)
8100 V8 Dual Rear Wheel 4.10 14,800 lbs (6 713 kg) 22,000 lbs (9 979 kg)
6.6L V8 Diesel Single Rear
Wheel3.73 14,700 lbs (6 668 kg) 22,000 lbs (9 979 kg)
6.6L V8 Diesel Dual Rear
Wheel (Manual)3.73 14,500 lbs (6 557 kg) 22,000 lbs (9 979 kg)
6.6L V8 Diesel Dual Rear
Wheel (Automatic)3.73 16,000 lbs (7 257 kg) 23,500 lbs (10 659 kg)
*Fifth-wheel or gooseneck kingpin weight should be 15 percent to 25 percent of trailer weight up to 3,500 lbs
(1 587 kg) maximum.
*Trailer rating limited to 12,000 lbs (5 443 kg) with weight distributing hitch.
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The Gross Combination Weight Rating (GCWR)
is the total allowable weight of the completely
loaded vehicle and trailer including any
passengers, cargo, equipment and conversions.
The GCWR for your vehicle should not be
exceeded.
You can ask your dealer for our trailering
information or advice, or you can write us at
the address listed in your Warranty and Owner
Assistance Information Booklet.
In Canada, write to:
General Motors of Canada Limited
Customer Communications Centre, 163-005
1908 Colonel Sam Drive
Oshawa, Ontario L1H 8P7Weight 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 409for more information about
your vehicle’s maximum load capacity.
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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.
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 chartfor 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.
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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). 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.
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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.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.
448

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.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.
449

Driving with a Trailer
{CAUTION:
If you have a rear-most window open and
you pull a trailer with your vehicle, carbon
monoxide (CO) could come into your
vehicle. You cannot see or smell CO. It
can cause unconsciousness or death. See
Engine Exhaust on page 174. To maximize
your safety when towing a trailer:
Have your exhaust system inspected
for leaks, and make necessary repairs
before starting on your trip.
Keep the rear-most windows closed.
CAUTION: (Continued)
CAUTION: (Continued)

If exhaust does come into your vehicle
through a window in the rear or
another opening, drive with your front,
main heating or cooling system on
and with the fan on any speed. This
will bring fresh, outside air into your
vehicle. Do not use the climate control
setting for maximum air because it
only recirculates the air inside your
vehicle. SeeClimate Control System
on page 230.
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. 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.
451

Auxiliary Battery
The auxiliary battery provision can be used to
supply electrical power to additional equipment that
you may choose to add, such as a slide-in camper.
If your vehicle has this
provision, this relay will
be located on the
passenger’s side of the
vehicle, next to the
auxiliary battery.
When using this provision, connection should only
be made to the upper stud (A) of the relay. Do not
make connections to the lower stud (B) of the relay.
The auxiliary battery circuit is protected by a
megafuse located behind the auxiliary battery.
Be sure to follow the proper installation instructions
that are included with any electrical equipment
that you install.Notice:Leaving electrical equipment on for
extended periods will drain the battery. Always
turn off electrical equipment when not in
use and do not use equipment that exceeds
the maximum amperage rating for the auxiliary
battery provision.
Power Winches
If you wish to use a power winch on your vehicle,
only use it when your vehicle is stationary or
anchored.
Trailer Recommendations
You must subtract your hitch loads from the CWR
for your vehicle. Weigh your vehicle with the
trailer attached, so that you won’t go over
the GVWR or GAWR. If you are using a
weight-distributing hitch, weigh the vehicle without
the spring bars in place.
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 429.
460

Noise Control System
Tampering with Noise Control
System Prohibited
The following information relates to compliance
with federal noise emission standards for vehicles
with a Gross Vehicle Weight Rating (GVWR) of
more than 10,000 lbs (4 536 kg). The Maintenance
Schedule provides information on maintaining
the noise control system to minimize degradation
of the noise emission control system during
the life of your vehicle. The noise control system
warranty is given in your warranty booklet.
These standards apply only to vehicles sold in the
United States.Federal law prohibits the following acts or the
causing thereof:
1. The removal or rendering inoperative by
any person, other than for purposes of
maintenance, repair or replacement, of any
device or element of design incorporated into
any new vehicle for the purpose of noise
control, prior to its sale or delivery to the
ultimate purchaser or while it is in use; or
2. The use of the vehicle after such device or
element of design has been removed or
rendered inoperative by any person.
Among those acts presumed to constitute
tampering are the acts listed below.
Insulation:

Removal of the noise shields or any
underhood insulation.
Engine:

Removal or rendering engine speed governor,
if the vehicle has one, inoperative so as to
allow engine speed to exceed manufacturer
specications.
531

(C) Aspect Ratio:A two-digit number that
indicates the tire height-to-width measurements.
For example, if the tire size aspect ratio is 75, as
shown in item C of the light truck (LT-Metric) tire
illustration, it would mean that the tire’s sidewall is
75 percent as high as it is wide.
(D) Construction Code:A letter code is used to
indicate the type of ply construction in the tire.
The letter R means radial ply construction;
the letter D means diagonal or bias ply
construction; and the letter B means belted-bias
ply construction.
(E) Rim Diameter:Diameter of the wheel in
inches.
(F) Service Description:The service description
indicates the load range and speed rating of a
tire. The load index can range from 1 to 279.
Speed ratings range from A to Z.Tire Terminology and Denitions
Air Pressure:The amount of air inside the tire
pressing outward on each square inch of the
tire. Air pressure is expressed in pounds
per square inch (psi) or kilopascal (kPa).
Accessory Weight:This means the combined
weight of optional accessories. Some examples of
optional accessories are, automatic transmission/
transaxle, power steering, power brakes, power
windows, power seats, and air conditioning.
Aspect Ratio:The relationship of a tire’s height
to its width.
Belt:A rubber coated layer of cords that is
located between the plies and the tread. Cords
may be made from steel or other reinforcing
materials.
Bead:The tire bead contains steel wires wrapped
by steel cords that hold the tire onto the rim.
Bias Ply Tire:A pneumatic tire in which the plies
are laid at alternate angles less than 90 degrees
to the centerline of the tread.
548