1994 GMC Safari Owner's Manual - Page 217

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. I NOTICE: Spinning your wheels can destroy parts of your vehicle as as well 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, spinning the wheels aslittle as possible. Release the accelerator pedal while you shift, and press lightly on the accelerator pedal when the transmission isin gear. If that doesn't get you out after a few tries, you may need to be towed out. If you do need to be towed out, see "Towing Your Vehicle" in the Index. 5-33