How to Drive So It Doesn't Break & Off Road Recovery
Updated April 19, 2016
The 4wd community is small as it is. I think that anyone that wants to be a part of it should be welcomed in. I don'tchoose to go out wheeling with people by what they drive,it's how they drive that matters.
My truck is a daily driver and I have to travel 1000 or more miles whenever I go off roading. What it boils down to is this; when on the highway keep it 65 or under. I'll just sit in the right lane at 63 with the cruise on and let everyone pass me. I never have to worry about getting a speeding ticket. Over 65 you will put stress on the drivetrain and overheat the transfercase (in the summer). Don't forget that the Hummer is not aerodynamic. It's like a moving brick. Resistance increases with speed. The truck will run all day and all night and be very happy below 65. You will also get 13 to 14 mpg.
My truck has been to Moab and Durango 4 times. To the Black hills at least 3 times, Colorado a bunch of times and to Windrock once. I'm sure I'm due. There reasons I haven't broken a shaft.
When I drive off road my goal is to drive smooth and with finesse. When I btm I try to use it just enough to get up and then slowly release the brake and drive smoothly over the obstacle to keep stress off the drivetrain as much as possible. I also like to drive in H whenever I can to keep the windup down. That's why I like the idea of a tcase mod that gives you a low unlock.
The second reason is when I'm stuck I'll try a couple of times to go over. I stop and purposely take a breather to keep from getting flustered and doing something stupid. I always let my wheels slowly come to a stop. When you're on the trail with a bunch of trucks breakage is often due peer pressure. How many times have we seen a driver just put the 'peddle to the metal' and break his truck. If I can't make it without the risk of breaking I'll just winch or get pulled over. In fact it's interesting to watch the women drive at the AMG test track. One reason they do so well is that they aren't that concerned with showing off. They are more worried about breaking the truck.
I think I developed these habits because living in Illinois I always have to drive long distances to get to the trails. This means that If I break I'm not going home until it's fixed and I could ruin my vacation. The other reason is that I've been wheeling since 1975 and never was in any kind of club before I got my 3rd Hummer so for the most part I was out alone.
I Just Got My Truck. How do I Drive it Off-Road?
First, the shifter which has a lever that moves you from Park to Reverse to Forward has a second lever .... it is for your T-case. This is your friend for 4 wheeling. You can shift into HL (high lock) while moving, certainly less than 40 mph. But the magic occurs with LL (low lock), it is here that your T-case is locked (powers front and back differentials equally) and it gears it down for maximum torque. To shift into LL, you must have the transmission in Neutral or Park. This is best done while the vehicle is stopped. Then with a mighty heave ho ... push the shifter into LL. Do not hesitate, shove it good! You hear a quick grinding then it is over. Now shift your transmission into gear. For a really steep hill where you need maximum torque going up or maximum engine braking going down, keep the transmission in 1st then crawl up or down your obstacle. For most off roading where Low Lock is needed, you can leave the transmission in D and let the transmission determine which of the gears it wants.
Next the differentials, these power the wheels evenly, until one slips. Unfortunately, the wheel that slips gets all the power (non-TT4 trucks, pre-1999) so here we use BTM. Brake Throttle Modulation is when you apply SOME brake, stop the spinning wheel and redistribute the power to both wheels. Do NOT hit your brakes when the wheels are spinning ... this is how you break halfshafts. Once you discover you can not move because one wheel is spinning in the front and one is spinning in the back ... take your foot off the gas, let the wheels stop. Now apply the brake. Then give it gas. Then release some of the brake and give it more gas as you move foreward. You do not need to see rpm's on a gauge ... this is all by feel. By the way, BTM is a low rpm maneuver. You will feel the truck move, if it can. If BTM does not work use a winch or have a second Hummer/ tractor pull you out with a strap.
Here we add another variable in 4 wheeling ... tire pressure. You can deflate your tires to have them flatten out. This gives more traction and also helps prevent wheel spinning which tears up the landscape.
Air down to 15 pounds. Put it
in low lock. Put the transmission in Drive. Visually find a theoretical
line on the hill which will not exceed your approach angle or departure angle or lead to high centering (where a rock or obstacle gets under the truck and lifts all the wheels off the ground) . Tell all the spectators to keep clear. Drive straight up the hill (traversing can be dangerous if you exceed your center of gravity).
Remember once off the pavement you may scratch your truck, tear off sidebars or steps or create general havoc.
Off Road Recovery
This is a very wide subject. I'd go searching on the net to find articles written on extracting your truck and the correct use of jacks and winches. Remember that a vehicle is very heavy and the chains and wire rope used to pull a truck out are under very high tension and can snap and break like a guitar string destroying everything in it's path including you.