GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9234758) - 2016 - crc - 11/9/15
Driving and Operating 339
Weight of the Trailering
Combination
It is important that the combination
of the tow vehicle and trailer does
not exceed any of its weight ratings
—GCWR, GVWR, RGAWR, Trailer
Weight Rating, or Tongue Weight.
The only way to be sure it is not
exceeding any of these ratings is to
weigh the tow vehicle and trailer
combination, fully loaded for the trip,
getting individual weights for each of
these items.
Towing Equipment
Hitches
The correct hitch equipment helps
maintain combination control. Many
trailers can be towed with a
weight-carrying hitch which simply
features a coupler latched to the
hitch ball, or a tow eye latched to a
pintle hook. Other trailers may
require a weight-distributing hitch
that uses spring bars to distribute
the trailer tongue weight among the
tow vehicle and trailer axles.
Fifth-wheel and gooseneck hitches
may also be used. See “Weight ofthe Trailer Tongue”
underTrailer
Towing 0325 for rating limits with
various hitch types.
If a step-bumper hitch will be used,
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.
Consider using sway controls with
any trailer. Ask a trailering
professional about sway controls or
refer to the trailer manufacturer's
recommendations and instructions.
Weight-Distributing Hitch and
Adjustment
A weight-distributing hitch may be
useful with some trailers. Use the
following guidelines to determine if a
weight-distributing hitch should
be used.
GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9234758) - 2016 - crc - 11/9/15
340 Driving and Operating
Vehicle SeriesTrailer WeightWeight-Distributing Hitch
Usage Hitch Distribution
1500 Up to 3175 kg (7,000 lb) OptionalRefer to trailer
manufacturer ’s
recommendation
1500 Over 3175 kg (7,000 lb) Required50%
2500/3500 Up to 8165 kg (18,000 lb) OptionalRefer to trailer
manufacturer ’s
recommendation
1. Front of Vehicle
2. Body to Ground Distance
When using a weight-distributing
hitch, measure distance (2) before
coupling the trailer to the hitch ball.
Measure the height again after the
trailer is coupled and adjust the
spring bars so the distance (2) is as
close as possible to halfway
between the two measurements.
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% of the
trailer weight up to the maximum
amount specified in the trailering
chart for the vehicle. See
“Weight of
the Trailer” underTrailer
Towing 0325.
The hitch should be located in the
pickup bed so that its 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
GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9234758) - 2016 - crc - 11/9/15
Driving and Operating 343
.White: Ground
. White/Green: Back-up Lamps
. Red/Green: Battery Feed
. Dark Blue: Trailer Brake
If the vehicle is equipped with the
heavy-duty trailering option, see
“Heavy-Duty Trailer Wiring Harness
Package” earlier in this section.
When the camper-wiring harness is
ordered without the heavy-duty
trailering package, a seven-wire
harness with a seven-pin connector
is at the rear of the vehicle and is
tied to the vehicle's frame.
Electric Brake Control Wiring
Provisions
These wiring provisions are
included with the vehicle as part of
the trailer wiring package. These
provisions are for an electric brake
controller.
The harness should be installed by
your dealer or a qualified service
center.
Tow/Haul Mode
Pressing this button at the end of
the shift lever turns on and off the
Tow/Haul Mode.
This indicator light on the instrument
cluster comes on when the Tow/
Haul Mode is on. Tow/Haul is a feature that assists
when pulling a heavy trailer or a
large or heavy load. See
Tow/Haul
Mode 0292.
Tow/Haul is designed to be most
effective when the vehicle and
trailer combined weight is at least
75% of the vehicle's Gross
Combined Weight Rating (GCWR).
See “Weight of the Trailer” under
Trailer Towing 0325. Tow/Haul is
most useful under the following
driving conditions:
. When pulling a heavy trailer or a
large or heavy load through
rolling terrain.
. When pulling a heavy trailer or a
large or heavy load in
stop-and-go traffic.
. When pulling a heavy trailer or a
large or heavy load in busy
parking lots where improved low
speed control of the vehicle is
desired.
Operating the vehicle in Tow/Haul
when lightly loaded or with no trailer
at all will not cause damage.
However, there is no benefit to the
GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9234758) - 2016 - crc - 11/9/15
350 Driving and Operating
Caution (Continued)
when a snow plow is installed.
The vehicle can be damaged if
either the front or rear axle ratings
or the Gross Vehicle Weight
Rating (GVWR) are exceeded.
Some vehicles are built with a
special snow plow prep package,
called RPO VYU. If the vehicle has
this option, you can add a plow to it,
provided certain weights, such as
the weights on the vehicle's axles
and the Gross Vehicle Weight
Rating (GVWR), are not exceeded.
The plow the vehicle can carry
depends on many things, such as:
. The options the vehicle came
with, and the weight of those
options.
. The weight and number of
passengers intended to be
carried.
. The weight of items added to the
vehicle, like a tool box or
truck cap. .
The total weight of any
additional cargo intended to be
carried.
Say, for example, you have a 318 kg
(700 lb) snow plow. The total weight
of all occupants and cargo inside
the cab should not exceed 135 kg
(300 lb). This means that you may
only be able to carry one passenger.
But, even this may be too much if
there is other equipment already
adding to the weight of the vehicle.
Here are some guidelines for safely
carrying a snow plow on the vehicle:
. Make sure the weight on the
front and rear axles does not
exceed the axle rating for each.
. For the front axle, if more cargo
or passengers must be carried,
appropriate counter ballast must
be installed rear of the rear axle.
Counter ballast must be properly
secured so it will not move
during driving.
. Follow the snow plow
manufacturer's
recommendations regarding rear
ballast. Rear ballast may be required to ensure a proper front
and rear weight distribution ratio,
even though the actual weight at
the front axle may be less than
the front axle rating.
. The snow plow manufacturer or
installer can assist you in
determining the amount of rear
ballast required, to help make
sure the snow plow/vehicle
combination does not exceed
the GVW rating, the front and
rear axle ratings, and the front
and rear weight distribution ratio.
. The total vehicle must not
exceed the GVW rating.
Front axle reserve capacity is the
difference between the Gross Axle
Weight Rating (GAWR) and the front
axle weight of the vehicle with full
fuel and passengers. Basically, it is
the amount of weight that can be
added to the front axle before
reaching the front GAWR.
GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9234758) - 2016 - crc - 11/9/15
Driving and Operating 351
United StatesCanada
The front axle reserve capacity for
the vehicle can be found in the
lower right corner of the
Certification/Tire label, as shown.
In order to calculate the amount of
weight any front accessory, such as
a snow plow, is adding to the front
axle, use the following formula:(W x (A + W.B.)) /W.B.= Weight the
accessory is adding to the
front axle.
Where: W = Weight of added accessory
A = Distance that the accessory
is in front of the front axle
W.B. = Vehicle Wheelbase
For example, adding a 318 kg
(700 lb) snow plow actually adds
more than 318 kg (700 lb) to the
front axle. Using the formula, if the
snow plow is 122 cm (4 ft) in front of
the front axle and the wheel base is
305 cm (10 ft), then: W = 318 kg (700 lb)
A = 122 cm (4 ft)
GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9234758) - 2016 - crc - 11/9/15
352 Driving and Operating
W.B. = 305 cm (10 ft)
(W x (A + W.B.)/W.B. =
(318 x (122 + 305))/305 = 445 kg
(980 lb)
So, if the front axle reserve capacity
is more than 445 kg (980 lb), the
snow plow could be added without
exceeding the front GAWR.
Heavier equipment can be added on
the front of the vehicle if it is
compensated for by carrying fewer
passengers or less cargo, or by
positioning cargo toward the rear.
This has the effect of reducing the
load on the front. However, the front
GAWR, rear GAWR, and Gross
Vehicle Weight Rating (GVWR) must
never be exceeded.
{Warning
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 (Continued)
Warning (Continued)
weight on the rear axle to have
proper braking performance. If the
brakes cannot work properly, you
could have a crash. To help the
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 the GVWR and
the weight of the truck with full fuel
and passengers. It is the amount of
weight that can be added to the vehicle before reaching the GVWR.
Keep in mind that reserve capacity
numbers are intended as a guide
when selecting the amount of
equipment or cargo the truck can
carry. If unsure of the vehicle's front,
rear, or total weight, go to a weigh
station and weigh the vehicle. Your
dealer can also help with this.
The total vehicle reserve capacity
for the vehicle can be found in the
lower right corner of the
Certification/Tire label as shown
previously.
See your dealer for additional
advice and information about using
a snow plow on the vehicle. Also,
see
Vehicle Load Limits 0269.
Emergency Roof Lamp
Provisions
Vehicles with the RPO VYU snow
plow prep package also have an
emergency roof lamp provision
package, RPO TRW. Wiring for the
emergency roof lamp is provided
above the overhead console. See
Auxiliary Roof-Mounted Lamp 0180
for switch location.
GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9234758) - 2016 - crc - 11/9/15
Vehicle Care 385
fill plug hole, located on the rear
axle. Add only enough fluid to
reach the proper level.
. For all 6.0L 2500HD Series
applications, the proper level is
from 0 mm to 13 mm (0 to 0.5 in)
below the bottom of the fill plug
hole, located on the rear axle.
Add only enough fluid to reach
the proper level.
. For all 6.6L Duramax Diesel
2500HD Series applications and
all 3500 Series applications, the
proper level is from 17 mm to
21 mm (0.6 in to 0.8 in) below
the bottom of the fill plug hole,
located on the rear axle. Add
only enough fluid to reach the
proper level.
What to Use
Refer to Recommended Fluids and
Lubricants 0463 to determine what
kind of lubricant to use.
Noise Control System
Noise Emission Warranty
General Motors warrants to the first
person who purchases this vehicle
for purposes other than resale and
to each subsequent purchaser that
this vehicle as manufactured by
General Motors was designed, built
and equipped to conform at the time
it left General Motors control with all
applicable U.S. EPA Noise Control
Regulations. This warranty covers
this vehicle as designed, built and
equipped by General Motors and is
not limited to any particular part,
component or system of the vehicle
manufactured by General Motors.
Defects in design, assembly or any
part, component or system of the
vehicle manufactured by General
Motors, which at the time it left
General Motors control caused
noise emissions to exceed Federal
standards, are covered by the
warranty for the life of the vehicle.
The following information relates to
compliance with federal noise
emission standards for vehicles with
a Gross Vehicle Weight Rating (GVWR) of more than 4 536 kg
(10,000 lb). The noise control
system warranty is given in your
warranty manual.
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.
GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9234758) - 2016 - crc - 11/9/15
Vehicle Care 405
(2) Tire Width:The three-digit
number indicates the tire section
width in millimeters from
sidewall to sidewall.
(3) 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 3 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.
(4) 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.
(5) Rim Diameter
:Diameter of
the wheel in inches.
(6) Load Range
:Load Range. (7) Service Description
:The
service description indicates the
load index and speed rating of a
tire. If two numbers are given as
in the example, 120/116, then
this represents the load index for
single versus dual wheel usage
(single/dual). The speed rating is
the maximum speed a tire is
certified to carry a load.
Tire Terminology and
Definitions
Air Pressure:The amount of
air inside the tire pressing
outward on each square inch of
the tire. Air pressure is
expressed in kPa (kilopascal)
or psi (pounds per square inch).
Accessory Weight
:The
combined weight of optional
accessories. Some examples of
optional accessories are
automatic transmission, 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 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.
Cold Tire Pressure
:The
amount of air pressure in a tire,
measured in kPa (kilopascal)
or psi (pounds per square inch)
before a tire has built up heat
from driving. See Tire
Pressure 0408.
Curb Weight
:The weight of a
motor vehicle with standard and
optional equipment including the