GMC 2011 Sierra - Manual (Page 310)

Black plate (16,1) GMC Sierra Owner Manual - 2011
9-16 Driving and Operating
Driving Across an Incline
An off-road trail will probably go
across the incline of a hill. To decide
whether to try to drive across the
incline, consider the following:
{
WARNING
Driving across an incline that is
too steep will make your vehicle
roll over. You could be seriously
injured or killed. If you have any
doubt about the steepness of the
incline, do not drive across it.
Find another route instead.
. A hill that can be driven straight
up or down might be too steep
to drive across. When going
straight up or down a hill, the
length of the wheel base — the
distance from the front wheels to
the rear wheels — reduces the
likelihood the vehicle will tumble
end over end. But when driving
across an incline, the narrower
track width — the distance
between the left and right
wheels — might not prevent the
vehicle from tilting and rolling
over. Driving across an incline
puts more weight on the downhill
wheels which could cause a
downhill slide or a rollover.
. Surface conditions can be a
problem. Loose gravel, muddy
spots, or even wet grass can
cause the tires to slip sideways,
downhill. If the vehicle slips
sideways, it can hit something
that will trip it — a rock, a rut,
etc. — and roll over.
. Hidden obstacles can make the
steepness of the incline even
worse. If you drive across a rock
with the uphill wheels, or if the
downhill wheels drop into a rut
or depression, the vehicle can tilt
even more.
For these reasons, carefully
consider whether to try to drive
across an incline. Just because
the trail goes across the incline
does not mean you have to drive it.
The last vehicle to try it might have
rolled over.
If you feel the vehicle starting
to slide sideways, turn downhill.
This should help straighten out
the vehicle and prevent the side
slipping. The best way to prevent
this is to “walk the course” first, so
you know what the surface is like
before driving it.