HUMMER H3 2010 Owners Manual

Driving and Operating 9-7
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
reflexes, 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 definite 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 fluid levels are where they
should be, and that the spare
tire is fully inflated.
.Be sure to read all the
information about
four-wheel-drive vehicles
in this manual.
.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.

9-8 Driving and Operating
Loading Your Vehicle for
Off-Road Driving
{WARNING
.Cargo on the load floor 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
floor can be tossed about
when driving over rough
terrain. You or your
passengers can be struck
by flying objects. Secure
the cargo properly.(Continued)
WARNING (Continued)
.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 floor, 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 find other important
information under
Vehicle Load
Limits
on page 9‑27and Tireson
page 10‑44.
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,
flowers, trees, or grasses or
disturb wildlife. This includes
wheel-spinning, breaking down
trees, or unnecessary driving
through streams or over soft
ground.

Driving and Operating 9-9
.Always carry a litter bag and
make sure all refuse is removed
from any campsite before
leaving.
.Take extreme care with open
fires (where permitted), camp
stoves, and lanterns.
.Never park your vehicle over
dry grass or other combustible
materials that could catch fire
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.
High Mobility Characteristics
The H3 has a 22.3 cm (8.8 inch)
running ground clearance (A), a
23.4 cm (9.2 inch) axle to ground
clearance (B), and a low center of
gravity.
The H3T has a 24.1 cm (9.5 inch)
running ground clearance (A), a
22.1 cm (8.7 inch) axle to ground
clearance (B), and a low center of
gravity.

9-10 Driving and Operating
The H3 has an approximate
approach angle (A) of 37.4 degrees
and an approximate departure
angle (B) of 34.7 degrees,
depending on suspension
packages.
The H3T has an approximate
approach angle (A) of 37.1 degrees
and an approximate departure
angle (B) of 31 degrees, depending
on suspension packages.Design specifications required a
minimum gradeability of 60%
(31 degrees) slope, with the
vehicle fully loaded, on high friction
surfaces with maximum vehicle
speed not to exceed 9.7 km/h
(6 mph). The vehicle is expected to
traverse this grade only for short
durations. Never stop and idle the
vehicle or park it on this grade.The vehicle should be able to
traverse a 40% (22 degrees) side
slope at 9.7 km/h (6 mph) while fully
loaded on high friction surfaces.

Driving and Operating 9-11
The vehicle can climb a 40.6 cm
(16 inch) vertical step. Step climbing
is best done by approaching the
step at an angle rather than
straight on.
Brake and Accelerator
Operation Techniques for
Off-Road Driving
For logs, walls, rocks, severe
ditches, hills, sand, etc.
1. Bring the vehicle to a completestop. Do not rev the engine.
2. Select the proper transmission and transfer case gear
range; usually 1 (First) gear,
Four‐Wheel‐Low 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 system,
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 first 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.

9-12 Driving and Operating
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 thebrakes.
2. Assess the terrain properly and adjust vehicle speed and gear
ranges accordingly: Four‐Wheel
High position for higher speeds
and Four‐Wheel‐Low 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.
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.
{WARNING
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.

Driving and Operating 9-13
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. 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 firm 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.

9-14 Driving and Operating
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. 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
25.4 cm (10 inches) in diameter.
Approach the log at approximately a
15° angle (A) with the transmission
in 1 (First) and the transfer case in
Four‐Wheel‐Low 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.
Driving on Hills
Off-road driving often takes you up,
down, or across a hill. Driving safely
on hills requires good judgment
and an understanding of what the
vehicle can and cannot do. There
are some hills that simply cannot be
driven, no matter how well built the
vehicle.

Driving and Operating 9-15
{WARNING
Many hills are simply too steep
for any vehicle. If you drive up
them, you will stall. If you drive
down them, you cannot control
your speed. If you drive across
them, you will roll over. You could
be seriously injured or killed.
If you have any doubt about the
steepness, do not drive the hill.
Approaching a Hill
When you approach a hill, decide if
it is too steep to climb, descend,
or cross. Steepness can be hard to
judge. On a very small hill, for
example, there may be a smooth,
constant incline with only a small
change in elevation where you can
easily see all the way to the top.
On a large hill, the incline may get
steeper as you near the top, but you
might not see this because the crest
of the hill is hidden by bushes,
grass, or shrubs.Consider this as you approach a hill:
.Is there a constant incline,
or does the hill get sharply
steeper in places?
.Is there good traction on the
hillside, or will the surface cause
tire slipping?
.Is there a straight path up or
down the hill so you will not
have to make turning
maneuvers?
.Are there obstructions on the hill
that can block your path, such
as boulders, trees, logs, or ruts?
.What is beyond the hill? Is there
a cliff, an embankment, a
drop-off, a fence? Get out and
walk the hill if you do not know.
It is the smart way to find out.
.Is the hill simply too rough?
Steep hills often have ruts,
gullies, troughs, and exposed
rocks because they are more
susceptible to the effects of
erosion.See
Hill Start Assist (HSA)
on
page 9‑52for information on
vehicles stopped on a grade.
Driving Uphill
Once you decide it is safe to drive
up the hill:
.Use transmission and transfer
case low gear and get a firm grip
on the steering wheel.
.Get a smooth start up the hill
and try to maintain speed. Not
using more power than needed
can avoid spinning the wheels or
sliding.
.Let the traction system work to
control any wheel slippage. The
traction control system allows for
moderate wheel spin with some
capability to dig in and power up
the hill.

9-16 Driving and Operating
.Do not continue if the vehicle
shudders or exhibits suspension
hopping. This can cause
damage to the driveline or
suspension components.
Improper driving technique is not
covered by the vehicle warranty.
{WARNING
Turning or driving across steep
hills can be dangerous. You could
lose traction, slide sideways, and
possibly roll over. You could be
seriously injured or killed. When
driving up hills, always try to go
straight up.
.Try to drive straight up the hill if
at all possible. If the path twists
and turns, you might want to find
another route.
.Ease up on the speed as you
approach the top of the hill.
.Attach a flag to the vehicle to be
more visible to approaching
traffic on trails or hills.
.Sound the horn as you approach
the top of the hill to let opposing
traffic know you are there.
.Use headlamps even during the
day to make the vehicle more
visible to oncoming traffic.
{WARNING
Driving to the top (crest) of a
hill at full speed can cause an
accident. There could be a
drop-off, embankment, cliff,
or even another vehicle. You
could be seriously injured or
killed. As you near the top of a
hill, slow down and stay alert.If the vehicle stalls, or is about to
stall, and you cannot make it up
the hill:
.Push the brake pedal to stop
the vehicle and keep it from
rolling backwards and apply the
parking brake.
.If the engine is still running, shift
the transmission to R (Reverse),
release the parking brake, and
slowly back down the hill in
R (Reverse).
.If the engine has stopped
running, you need to restart it.
With the brake pedal pressed,
apply the parking brake. If the
vehicle has an automatic
transmission, shift the
transmission to P (Park).
Restart the engine. Then, shift
to R (Reverse), release the
parking brake, and slowly back
down the hill as straight as
possible in R (Reverse).