2008 GMC YUKON Owner's Manual

Autoride®
If equipped, the Autoride®feature will provide a superior
vehicle ride and handling under a variety of passenger
and loading conditions.
The system is fully automatic and uses a computer
controller to continuously monitor vehicle speed, wheel
to body position, lift/dive and steering position of the
vehicle. The controller then sends signals to each shock
absorber to independently adjust the damping level to
provide the optimum vehicle ride.
Autoride
®also interacts with the tow/haul switch that,
when engaged, will provide additional control of the
shock absorbers. This additional control results in better
ride and handling characteristics when the vehicle is
loaded or towing a trailer. SeeTow/Haul Mode Light on
page 3-53for more information.
Towing a Trailer
If your vehicle is a Two-mode Hybrid, see the Two-mode
Hybrid manual for more information.
Do not tow a trailer during break-in. SeeNew Vehicle
Break-In on page 2-26for 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. You may also damage your
vehicle; the resulting repairs would not be
covered by your warranty. Pull a trailer only if
you have followed all the steps in this section.
Ask your dealer/retailer 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 that would
not be covered by your warranty. Always follow
the instructions in this section and check with your
dealer/retailer for more 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.
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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.
If You Do Decide To Pull A Trailer
If you do, here are some important points:
There are many different laws, including speed limit
restrictions, having to do with trailering. Make sure
your rig will be legal, not only where you live
but also where you’ll 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.
Don’t tow a trailer at all during the rst 500 miles
(800 km) your new vehicle is driven. Your engine,
axle or other parts could be damaged.
Then, during the rst 500 miles (800 km) that you
tow a trailer, don’t drive over 50 mph (80 km/h)
and don’t make starts at full throttle. This helps your
engine and other parts of your vehicle wear in at
the heavier loads.
You can tow in DRIVE (D). You may want to shift
the transmission to THIRD (3) or, if necessary, a
lower gear selection if the transmission shifts
too often (e.g., under heavy loads and/or hilly
conditions). See “Tow/Haul Mode” later in
this section.
Three important considerations have to do with weight:
The weight of the trailer
The weight of the trailer tongue
The weight on your vehicle’s tires
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Tow/Haul Mode
Tow/Haul is a feature that assists when pulling a heavy
trailer or a large or heavy load. The purpose of the
Tow/Haul mode is to:
Reduce the frequency and improve the predictability
of transmission shifts when pulling a heavy trailer or
a large or heavy load.
Provide the same solid shift feel when pulling a
heavy trailer or a large or heavy load as when
the vehicle is unloaded.
Improve control of vehicle speed while requiring
less throttle pedal activity when pulling a heavy
trailer or a large or heavy load.
Increase the charging system voltage to assist in
recharging a battery installed in a trailer.Press this button at the end of the shift lever to
enable/disable the tow/haul mode.
A light on the instrument
panel will illuminate to
indicate that tow/haul
mode has been selected.
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Your vehicle is equipped with a button at the end of the
shift lever which, when pressed, enables tow/haul.
Your vehicle may be equipped with Autoride
®which
further improves your vehicle’s ride while towing.
SeeAutoride
®on page 4-49for more information. When
the button is pressed, a light on the instrument panel
will illuminate to indicate that Tow/Haul has been
selected. Tow/Haul may be turned off by pressing the
button again, at which time the indicator light on
the instrument panel will turn off. The vehicle will
automatically turn off Tow/Haul every time it is started.
Tow/Haul is designed to be most effective when the
vehicle and trailer combined weight is at least 75 percent
of the vehicle’s Gross Combined Weight Rating
(GCWR). See Weight of the Trailer later in this section.
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 benet to the selection of Tow/Haul when the
vehicle is unloaded. Such a selection when unloaded
may result in unpleasant engine and transmission driving
characteristics and reduced fuel economy. Tow/Haul
is recommended only when pulling a heavy trailer or a
large or heavy load.
Weight of the Trailer
How heavy can a trailer safely be?
It depends on how you plan to use your rig. For
example, speed, altitude, road grades, outside
temperature and how much your vehicle is used to pull
a trailer are all important. It can also depend on any
special equipment that you have on your 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 one of the following charts to determine how much
your vehicle can weigh, based upon your vehicle
model and options.
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C-1500 (2WD) Axle Ratio Maximum Trailer Weight *GCWR
4800 V83.23
3.734,500 lbs (2 041 kg)
6,500 lbs (2 948 kg)10,000 lbs (4 536 kg)
12,000 lbs (5 443 kg)
5300 V83.42
3.736,500 lbs (2 948 kg)
7,500 lbs (3 402 kg)12,000 lbs (5 443 kg)
13,000 lbs (5 897 kg)
5300 V8 (Extended
Models)3.73
4.107,100 lbs (3 220 kg)
8,100 lbs (3 674 kg)13,000 lbs (5 897 kg)
14,000 lbs (6 350 kg)
6000 V8 (Extended
Models)4.10 8,100 lbs (3 674 kg) 14,000 lbs (6 350 kg)
K-1500 (4WD) Axle Ratio Maximum Trailer Weight *GCWR
5300 V83.73
4.107,200 lbs (3 266 kg)
8,200 lbs (3 719 kg)13,000 lbs (5 897 kg)
14,000 lbs (6 350 kg)
5300 V8 (Extended
Models)3.73
4.107,000 lbs (3 175 kg)
8,000 lbs (3 629 kg)13,000 lbs (5 897 kg)
14,000 lbs (6 350 kg)
6000 V8 (Extended
Models)4.10 8,000 lbs (3 629 kg) 14,000 lbs (6 350 kg)
C-2500 (2WD) Axle Ratio Maximum Trailer Weight *GCWR
6000 V8 (Extended
Models)3.73 9,700 lbs (4 400 kg) 14,000 lbs (6 350 kg)
K-2500 (4WD) Axle Ratio Maximum Trailer Weight *GCWR
6000 V8 (Extended
Models)3.73 9,300 lbs (4 218 kg) 14,000 lbs (6 350 kg)
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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.
Ask your dealer/retailer for our trailering information or
advice, or write us at our Customer Assistance
Offices. SeeCustomer Assistance Offices on page 7-5
for more information.
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. See Loading Your Vehicle for 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) 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 series with a weight distributing hitch.
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.
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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). Since the
rear axle already weighs 2,700 lbs (1 225 kg), adding1,275 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
seeLoading Your Vehicle on page 4-35for 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 will need the right hitch.
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