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  1. FrankDrebin Guest
    #1
    Got this at ai.ORG
    as posted by FReeMaN
    http://www.autoindustriya.com/yabbse...y;threadid=925


    Five Safety Tips When Taking Your Vehicle Off-Highway
    by Bill Burke

    It's 7 a.m., you hop in your sport utility vehicle, crank the starter, shift into gear and head out. The only thing is that your destination is right into the middle of traffic to the high-rise office, and not to the high-rise mountains! Like so many of us, the 4-wheel drive we bought usually only takes us to work and shopping, and our driving experience reflects that! When it is time to hit the trails and do some actual 4-wheeling, our skill level is hindered by lack of practice and the all too present level of fear--fear of damage, getting lost and getting stuck. These are real fears and have limiting consequences to the adventure called 4-wheeling. You could blunder along until something happens that turns you off to 4-wheeling, but it doesn't have to be like that. The learning curve and experience level do not need to include the damage, lost or stuck scenario!

    4-wheeling is not always about big torque and horsepower, lockers and big 35's. IT IS ABOUT FINESSE. The other stuff helps some, but finesse is the first and most important thing to acquire! Here are some hints to help you out in this area. Of course, there is no substitute for taking a class or experiential trip with me!

  2. FrankDrebin Guest
    #2
    1 - Drive as slow as possible, but as fast as necessary. There are times when in soft sand like beaches and washes, speed needs to be moderate and flotation through mud and snow needs to be kept up, hence "as fast as necessary." But usually taking your time on the trail will allow you to pick a smooth path and allow you time to react/act to the varieties of terrain like moving rocks and logs under the tires. If you have a ground clearance deficiency, going slow helps here, in that, if you do hit a rock with the diff or other rock grabber, it will usually stop the vehicle on impact or you will lightly scrape over it. If you were going too fast and hit a rock or other obstacle, it could knock a hole in the oil pan, diff or even knock off the oil filter.

    Don't get caught up in the Baja or Camel Trophy syndrome. They don't use those rigs as daily drivers. At the end of those events, the keys are handed over to a mechanic and a corporation that has deep pockets to refurbish them. Plus, you could get hurt!

  3. FrankDrebin Guest
    #3
    2 - Survey the trail ahead to avoid any "surprises." When in doubt, get out and recon! Make sure the trail goes beyond the obstacle, doesn't become a bottomless quagmire, has no back side to the hill (cliff?) or just plain ends. You can get a good idea where to place your tires and the differentials and have a plan of approach. And follow through to beyond the obstacle.

    Don't stop in the middle of the challenge to check it out.
    Get through it, then walk back and check it out again. See where you actually went. Observe your tire tracks.

  4. FrankDrebin Guest
    #4
    3 - Drive directly up and down hills. Traveling diagonally may result in a sideways slide -- worst case, a rollover.
    Know your approach and departure angles, the bumper to tire distance. Some trails will require off-camber driving. Just go slow, keeping the tires in the tracks. Don't lose attention and climb up a rock or stump on the up hillside. Vehicles will tend to slide sideways before rolling over. The tires will slip sideways a little. Stop if the slide puts you off the edge of the track. If it is clear downhill and a rollover is imminent, immediately turn the vehicle into the slide and drive it down. If that is not an option, and you are going over, turn the vehicle off and hold on to your seat-bottom and hope the seat belt works properly. You did have it on? There are other scenarios, but this is the least drastic. Use enough momentum to get up and over the hill. Avoid high centering on the crest. Use the engine brake method for the descent. Remember #2!

    DO NOT TURN AROUND WHEN ON A HILL. Rollover CAN happen. Practice backing down.

  5. FrankDrebin Guest
    #5
    4 - Reduce the tire pressure. This improves traction in all conditions, especially sand. Remember that ground clearance has been compromised. Reinflate before driving on the pavement for any distance.


    The easiest way to improve off-highway traction and performance is to "air-down." Depending on the tire you have and type of vehicle, you could go to as much as 15psi, even lower, if needed; for soft sand, 10psi.

    Be careful to not turn fast and push the tire off the bead.


    Usually, though, for most average 4-wheeling, 18 to 20psi will be enough. I know some folks who run 6psi. Highway pressure is another thing. The tire is marked on the side, i.e., 50psi at 3300 pounds. In essence, that one tire could hold my Defender up. Depending on the weight of the loaded vehicle and the size of tire, I have found that between 28 and 35 psi works in most on-highway applications. Read the manufacturer's label. The air pressure difference between the front and rear is due to the tire and auto manufacturers' experimentation for over/under steer and load variances. Carry a mini-compressor to reinflate, or know that an air pump is not far from the trail end. For snow, on- and off-highway, I like to run my tires a little hard. It allows the edges to grip better, especially if I am going to run chains.

  6. FrankDrebin Guest
    #6
    5 - Cross ditches or logs at an angle so that one wheel at a time goes over the obstacle; the other three help the one wheel to climb over. Dropping the tire into a ditch or crack in a rock is scary! Sometimes the vehicle pitches and one or more tires will catch air. Be very deliberate and careful when approaching this challenge section of any trail. Logs can bounce up and catch the undercarriage, so come off these things slowly and carefully. Turn the vehicle at an angle to facilitate the one tire at a time approach. Be careful not to allow one of the front tires and one of the rear tires to get in the ditch at the same time.

  7. FrankDrebin Guest
    #7
    Remember to breathe frequently and sit back and enjoy the ride. All too often, I find my student and client stressing out and clutching the wheel hunched over with the back and shoulder muscles tensed. Relax. That is what you are in the woods for, right? The Zen of the destination is the journey!

  8. FrankDrebin Guest
    #8
    6 - Get to know your vehicle and its performance potential. SQUEEZE the accelerator gently to avoid wheelspin, backing off the pedal when spin does occur, then gaining traction again. A spinning wheel/tire combo, no matter how large, does not give traction. That dirt pile doesn't know the difference from a Mud T/A or a Pirelli Red Line if it is spinning at 80 mph. You still won't get traction. You can't steer, brake or go with a spinning tire! Feel the point where the vehicle is about to stall, squeeze the throttle lightly, then back off the throttle, especially during rock crawling, up hill and snowed-in trails. With automatics you may have to use the left foot on the brake sometimes. Usually when you take your foot off the accelerator, the vehicle seems to "stall," so you put your foot back on the gas pedal and then the vehicle goes too fast. This "herky-jerky" method can be avoided by using finesse with left foot braking and proper throttle modulation. Know your vehicle and the actions and noises of the engine and suspension as you go over the trail.

  9. FrankDrebin Guest
    #9
    7 - Avoid lengthy wheelspin; digging into the track only gets you more stuck and ruins the environment. If stuck into the track, use a jack to lift the vehicle. Build up the ground under the tires. Placing brushwood and blankets, etc. under the tires will sometimes help with clearance. On the other hand, once in a while, you will have to let the tires "dig" a little to help forward momentum. If you feel the vehicle starting to lose traction or forward motion, try backing off the throttle then giving a short "blip" on the throttle. Try this a few times in quick succession. If this fails, back up and get another look at the obstacle and try a different approach.

    When you think you are getting stuck and the driving tricks don't seem to be helping, immediately back out of the obstacle. Use the winch to get through or go somewhere else. Don't drive off the trail and around the challenge unless there is a legitimate by-pass.

    Rocking the vehicle back and forth only serves to dig you in deeper. Sometimes it helps to rock back and forth, then to back out of the obstacle, but usually I don't like to dig deeper. Check under the vehicle to see what is holding it; a rock? a stump? or other grabber thing? Make sure those things are clear before winching or using the recovery strap. In soft sand, I carry 4 long (about 4 feet), thin (tire width) rolls of carpet. They help to get the vehicle rolling out of the sand traps. And, of course, always carry a well-stocked recovery kit!

  10. FrankDrebin Guest
    #10
    8 - Keep the use of the brakes to an absolute minimum to keep the wheels from locking up on wet, muddy, loose rock Descend steep slopes in low range and first gear. Rely on engine compression to slow the vehicle. If sliding occurs, drive the vehicle forward to gain traction once again, then back off the throttle. Sometimes when in extreme rocky descents with ledges and shelf steps, the clutch must be pushed in and the brakes used to allow the vehicle to creep forward ever so slowly. This should only be done in those cases. Usually engine control through throttle modulation is best served by engine compression on descents. A locked sliding tire gets no traction.

    BEWARE of the LURCH and SURGE! Unless you have lockers engaged on both axles, the lurch and surge will scare the heck out of you until you have experienced it many times. When in gear, no brakes, and open diffs, the vehicle has traction from only one tire on an axle--you know what happens when going uphill and getting traction to only one tire per axle. Well, when going downhill, if the tire that has contact to the transmission gets air or slides, the vehicle will lurch forward because the non-tractive tire has no resistance from the gear box. Usually it is a short surge, and control is gained when the tire contacts good terrain. When that is likely, a light foot pressure on the brake pedal will help to prevent the next lurch. The vehicle will actually "shoot" forward fast for a short distance. If not controlled or anticipated, you could gain momentum and quickly get out of control, especially on long descents.

    The same happens when backing down off an ascent as well. When backing down, always be in reverse gear. The same procedure pertains as in the descent. This is especially important when backing down, as the front end becomes light and the steering tires won't give the afforded traction for steering, traction and braking.

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OFFROAD SAFETY TIPS