GMC Sierra Hybrid 2011 Owner's Manual page 16

4-8 Storage
3. If the pickup box has molded
bed rail protectors (A), remove
the insert (C) from the outer
groove on the clamp, and
position the clamp on the side
rail (B) using the outer
groove (D).
4. Slide the inner clamp (B) into the
outer clamp (A).
5. Turn the latch (C) onto the outer
clamp.
6. Tighten the clamp by turning the
latch (C) toward the side rail.
Make sure there is no gap
between the rubber clamp pad
and the side rail.
7. If the truck box has a molded
bed rail protector, insert the latch
into the top notch on the inner
clamp.
8. Clean the vehicle's painted
surface below the pull strap
using a 50/50 mixture of rubbing
alcohol and tap water.