trailer HUMMER H3 2008 User Guide

Your Driving, the Road, and Your Vehicle..........4-2
Defensive Driving...........................................4-2
Drunk Driving.................................................4-2
Control of a Vehicle........................................4-3
Braking.........................................................4-3
Antilock Brake System (ABS)...........................4-4
Braking in Emergencies...................................4-5
Traction Control System (TCS).........................4-5
Locking Rear Axle..........................................4-6
StabiliTrak
®System........................................4-7
Steering........................................................4-8
Off-Road Recovery.......................................4-10
Passing.......................................................4-10
Loss of Control.............................................4-10
Off-Road Driving...........................................4-12
Assist Steps.................................................4-31Driving at Night............................................4-32
Driving in Rain and on Wet Roads..................4-33
Before Leaving on a Long Trip.......................4-34
Highway Hypnosis........................................4-34
Hill and Mountain Roads................................4-34
Winter Driving..............................................4-35
If Your Vehicle is Stuck in Sand,
Mud, Ice, or Snow.....................................4-39
Rocking Your Vehicle to Get It Out.................4-40
Recovery Loops...........................................4-40
Loading Your Vehicle....................................4-42
Towing..........................................................4-48
Towing Your Vehicle.....................................4-48
Recreational Vehicle Towing...........................4-48
Towing a Trailer...........................................4-50
Trailer Recommendations...............................4-62
Section 4 Driving Your Vehicle
4-1

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 4-50for
important information on towing a trailer,
towing safety, and trailering tips.
Item Description Total
AVehicle Capacity
Weight for
Example 1=1,000 lbs
(453 kg)
BSubtract
Occupant Weight
150 lbs (68 kg) x 2=300 lbs (136 kg)
CAvailable Cargo
Weight =700 lbs (317 kg)
Example 1
4-44

Refer to your vehicle’s Tire and Loading Information
label for specic information about your vehicle’s
capacity weight and seating positions. The
combined weight of the driver, passengers, cargo
and any accessories or equipment added to your
vehicle after it left the factory should never exceed
your vehicle’s capacity weight.
Certication/Tire Label
A vehicle specic Certication/Tire label is
attached to the bottom section of the center
pillar (B-pillar), on the driver’s side of the vehicle.The label shows the Gross Vehicle Weight
Rating (GVWR). The GVWR includes the weight
of the vehicle, all occupants, fuel, cargo and trailer
tongue weight, if pulling a trailer.
The Certication/Tire label also tells you the
maximum weights for the front and rear axles,
called Gross Axle Weight Rating (GAWR).
To nd out the actual loads on your front and
rear axles, you need to go to a weigh station
and weigh your vehicle. Your dealer can help
you with this. Be sure to spread out your
load equally on both sides of the centerline.
Never exceed the GVWR for your vehicle, or
the GAWR for either the front or rear axle.
If you do have a heavy load, you should
spread it out.
Similar appearing vehicles may have different
GVWRs and capacity weights. Please note your
vehicle’s Certication/Tire label or consult
your dealer for additional details.
Label Example
4-46

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 7-6.
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
with 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/retailer 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 4-34.
4-48

Towing a Trailer
{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 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 handling,
acceleration, braking, 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.
4-50

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.
If you have an automatic transmission, you can tow
in DRIVE (D). You may want to shift the transmission
to THIRD (3) or, if necessary, a lower gear if the
transmission shifts too often under heavy loads
and/or hilly conditions. If you have a manual
transmission and you are towing a trailer, it is
better not to use the highest gear.
Three important considerations have to do with weight:
The weight of the trailer
The weight of the trailer tongue
And the weight on your vehicle’s tires
4-51

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 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 the following chart to determine how much
your vehicle can weigh, based upon your vehicle
model and options.
Engine Axle Ratio Maximum Trailer Weight *GCWR
Automatic Transmission, 3.7L Engine 4.56 4,500 lbs (2 041 kg) 9,500 lbs (4 309 kg)
Automatic Transmission, 5.3L Engine 4.10 6,000 lbs (2 721 kg) 11,400 lbs (5 171 kg)
Manual Transmission 4.56 3,000 lbs (1 364 kg) 8,000 lbs (3 629 kg)
*The Gross Combination Weight Rating (GCWR) in 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 7-5for more information.
4-52

Weight of the Trailer Tongue
The tongue load (A) of any trailer is an important weight
to measure because it affects the total 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.
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 4-42
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 (B), up to
a maximum of 500 lbs (227 kg) with a weight carrying
hitch or 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.
Your spare tire carrier is behind the tailgate. If your
hitch extension is too short, the spare tire may interfere
with trailer coupling or trailer tongue jack operation
on some types of trailers.
4-53

After you’ve loaded your trailer, weigh the trailer and
then the tongue, separately, to see if the weights
are proper. If they aren’t, you may be able to get
them right simply by moving some items around
in the 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/Tire Label located on the B-pillar below the
door latch or seeLoading Your Vehicle on page 4-42.
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
When using a weight-distributing hitch, the hitch must be
adjusted so that the distance (A) remains the same both
before and after coupling the trailer to the tow vehicle.
Trailering may also 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.(A) Body-to-Ground Distance (B) Front of Vehicle
4-54

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.
4-55