HUMMER H2 2009 Owners Manual

Page 301 of 524

Off-Road Driving
The airbag system is designed to work properly under a
wide range of conditions, including off-road usage.
Always wear your safety belt and observe safe driving
speeds, especially on rough terrain.
Drinking and driving can be very dangerous on any road
and this is certainly true for off-road driving. At the very
time you need special alertness and driving skills, your
reexes, perceptions, and judgment can be affected
by even a small amount of alcohol. You could have a
serious — or even fatal — accident if you drink and drive
or ride with a driver who has been drinking.
Off-roading can be great fun but has some denite
hazards. The greatest of these is the terrain itself. When
off-road driving, traffic lanes are not marked, curves
are not banked, and there are no road signs. Surfaces
can be slippery, rough, uphill, or downhill.
Avoid sharp turns and abrupt maneuvers. Failure to
operate the vehicle correctly off-road could result in loss
of vehicle control or vehicle rollover.
Off-roading involves some new skills. That is why it is
very important that you read these driving tips and
suggestions to help make off-road driving safer
and more enjoyable.
Before You Go Off-Roading
Have all necessary maintenance and service
work done.
Make sure there is enough fuel, that uid levels are
where they should be, and that the spare tire is fully
inated.
Be sure to read all the information about
four-wheel-drive vehicles in this manual.
Make sure any equipment you may need — rst aid
kit, cell phone, ashlight, etc. — is securely stored
in the vehicle.
Remove any removable side steps. SeeAssist
Steps on page 4-33.
Make sure all underbody shields, if the vehicle has
them, are properly attached.
Know the local laws that apply to off-roading where
you will be driving or check with law enforcement
people in the area.
Be sure to get the necessary permission if you will
be on private land.
4-15

Page 302 of 524

Loading Your Vehicle for Off-Road
Driving
{CAUTION:
Cargo on the load oor piled higher than the
seatbacks can be thrown forward during a
sudden stop. You or your passengers could
be injured. Keep cargo below the top of the
seatbacks.
Unsecured cargo on the load oor can be
tossed about when driving over rough terrain.
You or your passengers can be struck by
ying objects. Secure the cargo properly.
Heavy loads on the roof raise the vehicle’s
center of gravity, making it more likely to roll
over. You can be seriously or fatally injured if
the vehicle rolls over. Put heavy loads inside
the cargo area, not on the roof. Keep cargo in
the cargo area as far forward and low as
possible.There are some important things to remember about
how to load your vehicle.
The heaviest things should be on the oor, forward
of the rear axle. Put heavier items as far forward
as you can.
Be sure the load is properly secured, so things are
not tossed around.
You will nd other important information underLoading
the Vehicle on page 4-44andTires on page 5-57.
4-16

Page 303 of 524

Environmental Concerns
Off-road driving can provide wholesome and satisfying
recreation. However, it also raises environmental
concerns. We recognize these concerns and urge every
off-roader to follow these basic rules for protecting
the environment:
Always use established trails, roads, and areas that
have been specially set aside for public off-road
recreational driving and obey all posted regulations.
Avoid any driving practice that could damage shrubs,
owers, trees, or grasses or disturb wildlife. This
includes wheel-spinning, breaking down trees, or
unnecessary driving through streams or over soft
ground.
Always carry a litter bag and make sure all refuse is
removed from any campsite before leaving.
Take extreme care with open res (where permitted),
camp stoves, and lanterns.
Never park your vehicle over dry grass or other
combustible materials that could catch re from the
heat of the vehicle’s exhaust system.
Traveling to Remote Areas
It makes sense to plan your trip, especially when going
to a remote area. Know the terrain and plan your route.
Get accurate maps of trails and terrain. Check to see if
there are any blocked or closed roads.
It is also a good idea to travel with at least one other
vehicle in case something happens to one of them.
For vehicles with a winch, be sure to read the winch
instructions. In a remote area, a winch can be handy if
you get stuck but you will want to know how to use
it properly.
4-17

Page 304 of 524

High Mobility Characteristics
The vehicle has a 10 inch (25.4 cm) running ground
clearance (A) and a 9 inch (22.8 cm) axle to ground
clearance (B) while maintaining a low silhouette and a
low center of gravity.
4-18

Page 305 of 524

The vehicle has an approximate approach angle (A) of
42° and a departure angle (B) of 37°.
Design specications required a minimum gradeability of
60% (31°) slope, with the vehicle fully loaded, on high
friction surfaces at 6 mph (9.7 km/h). The vehicle is
expected to traverse this grade only for short durations.
Never stop and idle the vehicle or park it on this grade.
4-19

Page 306 of 524

The vehicle should be able to traverse a 40% (22°) side
slope at 6 mph (9.7 km/h) while fully loaded on high
friction surfaces.The vehicle can climb a 16 inch (40.6 cm) vertical step.
Step climbing is best done by approaching the step
at an angle rather than straight on.
4-20

Page 307 of 524

Brake and Accelerator Operation
Techniques for Off-Road Driving
For logs, walls, rocks, severe ditches,
hills, sand, etc.
1. Bring the vehicle to a complete stop. Do not rev the
engine.
2. Select the proper transmission and transfer case
gear range; usually 1 (First) gear, 4LO LOCK for
such obstacles.
3. If wheel spin is experienced, maintain steady throttle,
with your foot off the brake pedal, to allow the
Traction Control System (TCS) to control the wheel
spin. TCS might not operate if the brakes are
applied.
4. If wheel spin cannot be controlled by the TCS, fully
press the brake pedal with your left foot so all
wheel spin is stopped.
5. Back away from the obstacle so that a new
approach can be tried.
6. As the rst wheel crosses the obstacle, be prepared
to alternate the brake and accelerator pedal to
maintain control and avoid tire drop-off from
obstacles. Repeat this process for the other wheels.
For mounds, washouts, loose up-hill
slopes, ditches, etc.
When wheel spin occurs as the vehicle is moving, the
driver may notice a slight shaking or shuddering of
the vehicle. This should be stopped as soon as possible
to prevent damage to vehicle components. This is the
indication that a loss of traction is occurring on this
terrain. The operator should:
1. Reduce speed and apply the brakes.
2. Assess the terrain properly and adjust vehicle
speed and gear ranges accordingly: 4HI position
for higher speeds and 4LO LOCK for more torque
and lower speeds. Transmission 1 (First) gear
is generally recommended.
3. Apply slight pressure to the brake when the shaking
or shuddering sensation is felt, keeping the vehicle
moving in a controlled manner.
4. Be prepared to alternate between braking and
accelerating through the adverse terrain.
4-21

Page 308 of 524

Getting Familiar with Off-Road Driving
It is a good idea to practice in an area that is safe
and close to home before you go into the wilderness.
Off-roading requires some new and different skills.
Tune your senses to different kinds of signals. Your eyes
need to constantly sweep the terrain for unexpected
obstacles. Your ears need to listen for unusual tire
or engine sounds. Use your arms, hands, feet, and body
to respond to vibrations and vehicle bounce.
Controlling the vehicle is the key to successful off-road
driving. One of the best ways to control the vehicle
is to control the speed. At higher speeds:
You approach things faster and have less time
to react.
There is less time to scan the terrain for obstacles.
The vehicle has more bounce when driving over
obstacles.
More braking distance is needed, especially on an
unpaved surface.
{CAUTION:
When you are driving off-road, bouncing and quick
changes in direction can easily throw you out of
position. This could cause you to lose control and
crash. So, whether you are driving on or off the
road, you and your passengers should wear
safety belts.
Scanning the Terrain
Off-road driving can take you over many different kinds
of terrain. Be familiar with the terrain and its many
different features.
Surface Conditions:Off-roading surfaces can be
hard-packed dirt, gravel, rocks, grass, sand, mud, snow,
or ice. Each of these surfaces affects the vehicle’s
steering, acceleration, and braking in different ways.
Depending on the surface, slipping, sliding, wheel
spinning, delayed acceleration, poor traction, and longer
braking distances can occur.
4-22

Page 309 of 524

Surface Obstacles:Unseen or hidden obstacles can
be hazardous. A rock, log, hole, rut, or bump can startle
you if you are not prepared for them. Often these
obstacles are hidden by grass, bushes, snow, or even
the rise and fall of the terrain itself.
Some things to consider:
Is the path ahead clear?
Will the surface texture change abruptly up ahead?
Does the travel take you uphill or downhill?
Will you have to stop suddenly or change direction
quickly?
When driving over obstacles or rough terrain, keep a rm
grip on the steering wheel. Ruts, troughs, or other surface
features can jerk the wheel out of your hands.
When driving over bumps, rocks, or other obstacles, the
wheels can leave the ground. If this happens, even with
one or two wheels, you cannot control the vehicle as well
or at all.
Because you will be on an unpaved surface, it is
especially important to avoid sudden acceleration,
sudden turns, or sudden braking.
Off-roading requires a different kind of alertness from
driving on paved roads and highways. There are no road
signs, posted speed limits, or signal lights. Use good
judgment about what is safe and what is not.
Crossing Obstacles
Approach Angle — a Key to Mobility
If you encounter a large dip in the terrain, do not
enter straight on; enter at an angle — 15° minimum
approach (A), 75° maximum approach angle (B). For
very large dips, ditches or small washes, coast in, using
the engine as a brake (transmission and transfer case
lowest gears). Then, use the low ranges in the
transmission and transfer case to power out.
4-23

Page 310 of 524

Roll The Tires Over Large Rocks
Do not straddle large rocks;
drive over them, letting the
tire cover the rock. The
tread of the tire is thicker
and tougher than the
sidewall of the tire and is
more resilient to impact
than underbody
components.
Log Crossing
Using the proper technique, the vehicle will cross logs
up to 10 inches (25.4 cm) in diameter. Approach the log
at approximately a 15° angle (A) with the transmission
in 1 (First) and the transfer case in 4LO LOCK and “walk”
the vehicle over, one tire at a time. It may be necessary to
modulate the brake pedal and accelerator to avoid
spin-out. Ease the vehicle down from the log with the
brake.
4-24

Page:   < prev 1-10 ... 261-270 271-280 281-290 291-300 301-310 311-320 321-330 331-340 341-350 ... 530 next >