Hi. Just to ask how and when to use the 4 wheel drive function on my 1999 Jeep Grand Cherokee with Quadra Trac2. The Jeep,s small stick next to the gear stick has been on 4 All Time level all the time and I am next week going to a farm, which is muddy and has a lot of sand. Just in case I get stuck in mud or sand, How do I pull myself out?