If You're Stuck: In Sand. Mud. Ice Or Snow - GMC 1994 Yukon Owner's Manual

If You're Stuck: In Sand, Mud, Ice or Snow
What you don't want to do when your vehicle is stuck is to spin your
wheels. The method known as "rocking" can help you get out when you're
stuck, but you must use caution.
NOTICE:
Spinning your wheels can destroy parts of your vehicle as well as
the tires. If you spin the wheels too fast while shifting your
transmission back and forth, you can destroy your transmission.
Rocking your vehicle to get it out:
First, turn your steering wheel left and right. That will clear the area around
your front wheels. Then shift back and forth between "R' (Reverse) and a
forward gear (or with a manual transmission, between First or Second gear
and Reverse), spinning the wheels as little as possible. Release the
accelerator pedal while you shift, and press lightly on the accelerator pedal
when the transmission is in gear. If that doesn't get you out after a few tries,
you may need to be towed out. Or, you can use your recovery hooks, if your
vehicle has them. If you do need to be towed out, see "Towing Your
Vehicle" in the Index.