GMC 2011 Sierra Denali Owner's Manual page 260

9-8 Driving and Operating
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 all-wheel-drive
and 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.
If you think you will need some
more ground clearance at the
front of your vehicle, you can
remove the front fascia lower air
dam. The air dam is held in place
by 2 bolts and 10 snaps accessible
from underneath the front fascia.
To remove the air dam:
1. Remove the 2 outboard air
dam bolts.
2. With a flat blade tool, disengage
the snaps.
3. After the bolts are removed and
the snaps are disengaged, push
forward on the air dam until it
is free.
Notice: Operating your vehicle
for extended periods without
the front fascia lower air dam
installed can cause improper air
flow to the engine. Always be
sure to replace the front fascia
air dam when you are finished
off-road driving.
After off-roading, be sure to reinstall
the air dam:
1. Line up the snaps and push the
air dam rearward to engage the
snaps.
2. Install the two outboard bolts.
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)