Climbing a hill
- Approach path
If you are facing a steep or slippery hill, having an approach path to gain speed can reduce the loss of traction when driving uphill. If there is no room for an adequate approach path an alternate route can be used. An approach path however should be limited to surfaces with no potholes or other large irregularities When there is room on the surface, it is better to climb at a slow constant pace to reduce damage on the vehicle’s underbody.
- Driving recommendations
1. Speed, distance and direction: Make an approach at an appropriate speed and from sucient distance. Climb the slope directly towards the crest.
2. Long slops: When climbing a long slope, keep a constant speed.
3. Operating the Clutch: (when the vehicle is equipped with a manual transmission): It is better to not switch gears when driving a manual transmission. However, if a gear shift is required, do it quickly and with little clutch use in order to avoid loss of momentum and traction.
4. Acceleration: When climbing a hill, use constant acceleration and ease o the pedal when reaching the crest to avoid damaging the vehicle underbody. If the tires loose traction due to an excessively slippery surface, slowly reduce the amount of acceleration to return traction to the wheels.
If you completely loose forward momentum and begin to slip before reaching the top, use the engine and transmission to brake (only for manual transmission vehicles) to recover. Keep the vehicle pointed towards the upper portion of the hill and use your rear view mirrors to guide you along your descent. It is best to avoid braking in order to avoid wheel lockup. However, brake softly to keep the vehicle under control* when your vehicle has an automatic transmission since the engine will not be able to assist in slowing you down.
Driving down a Hill
- Driving Tips
1. Gear selection and braking: Choose a low gear (or reduction gear in an automatic transmission) to take advantage of the engine’s braking capacity, reducing the use of the conventional brakes. When driving down a steep slope, it’s advisable to choose “L4” or “LL” to obtain maximum engine braking capacity. Depending on the vehicle’s transmission (automatic or manual) and the driving conditions, you may have to use the brake pedal.
2. Maintaining course: Drive down a hill perpendicular to the base. If tires loose traction, accelerating softly may return traction and steering control.
3. Long slopes: Vehicles tend to increase speed when going downhill continuously.
4. Clutch operation: When driving downhill, do not apply the clutch since this will eliminate the engine brake, causing a loss of traction and acceleration. This is one of the most dangerous things to do when driving downhill.
Holes or wading areas
- Driving Tips
1. Approach angle and path: Approach crevasses and holes (ditches) at an angle which allows for maximum control. Direct approaches may result in impacting the front bumper or the skid plate against the edge of the hole. By approaching at an angle, the space to maneuver is increased. Approaching at an angle also makes the tires overcome the obstacle one by one, reducing stress on the chassis. It is important at this time for at least three of the four wheels to maintain traction. Make sure to use the vehicle in 4WD mode at all times with the center differential lock applied (if applicable) to drive in these conditions.
Warning: If you are approaching at an incorrect angle, both wheels may enter the ditch at the same time, which can cause you to become stuck. Drive with caution.
Approach the ditch at an angle and allow for the tires to enter one by one:
2. Driving speed and acceleration: Slowly let the tires enter the gap one at a time. Then, accelerate gently until the tire begins to exit the ditch and decelerate immediately after the tires pass the obstacle. Repeat this process with each of the four tires. On slippery surfaces, increase or decrease speed as deemed necessary.
3. Reduce depth or inclination: When the depth or the angle of an obstacle is too great, adjustments can be made by placing a rock or another object where the tire makes impact.
Have the tire make contact with the “wall” of the gap/ditch and then accelerate softly to make the tire overcome the “wall”. Decelerate immediately after the tire overcomes the “wall”.
- Driving Tips
1. Approach angle: Dierent procedures must be made depending on the circumstances. Regardless of the procedure chosen, make sure the driver’s side is facing the ascending incline (looking up towards the summit). This gives the driver a greater sense of security.
2. Driving speed and acceleration: Constant acceleration and driving speed is always best.
- Driving Tips
1. Path: Drive only on shallow mud (the depth of the mud should never be above the lower portion of the center differential). Keep the wheels on the most solid terrain possible.
2. Gear selection: Choose a lower gear which you are able to control on muddy surface. If the vehicle is equipped with locking differentials, make sure they are locked.
3. Clutch operation: Maintain speed in such a way that you do not loose traction and not required to shift gears. Shifting may result in sudden deceleration and make the vehicle become stuck.
4. Steering operation: Turning the steering wheel on muddy terrain may increase the surface resistance. Try to keep the steering as straight as possible.
5. Adjusting tire pressure: On muddy surfaces, the mud may become stuck on the gaps between the tire tread (contact patch), reducing traction which make the vehicle easily become stuck. To avoid this from happening, reduce tire pressure to 1.2 kg/cm to 1.5 kg/cm (17 to 21 psi). This results in an increase in traction. If the mud is too wet, increasing tire pressure may result in an increase in traction, which will result in less mud getting stuck on the tires.
On muddy terrain, consider the use of tire chains.
- Driving Tips
1. Approach angle and path: Choose a path going downstream. Driving against the ow of water may make the vehicle become stuck. Also avoid water depth greater than the center of the wheels. In places where a river is owing slowly, you should be especially careful of mud and sand accumulations on the river bed. Water is usually deeper than it looks, which is why you should add between 20 to 30 cms to the appeared depth from the surface.
2. Gear selection and speed: L4 (part time) or LL (full time) is a good gear selection and constant acceleration will avoid water from entering the engine and exhaust. If water enters the air intake or electrical system this will cause water hammering/broken connecting rods* or a short circuit.
3. Steering operation: The ground beneath the water may not be visible due to mud or reection on the surface. These situations may cause the vehicle to become stuck in a gap on the river oor. To avoid accidents in these situations, your thumbs should never be on the inside portion of the steering wheel.
4. Choose where you will exit: Where you exit the river should be a solid surface will a small incline. Many vehicles become stuck when exiting a river.
Water hammering / broken connecting rods: if the amount of water which enters an engine’s combustion chamber exceeds its capacity, the appropriate engine combustion stops. This may cause the connecting rod to bend or break, as well as possibly damaging the piston.
- Driving Tips
1. Traction and tire pressure: On sandy terrain the surface is usually soft with a high degree of resistance, similar to muddy terrain. This is why gaining traction on sand is dicult. To avoid becoming stuck, reduce your tire pressure. However, reducing pressure excessively may cause the tires to separate from the wheels, which will bring a whole new series of problems.
2. Gear selection: Considering the lack of traction, “L4” (LL) is a good choice. If your vehicle come equipped with locking differentials, use them.
3. Steering and clutch operation: Do not turn suddenly. Operating the clutch may cause the vehicle to become stuck. Therefore, use a gear which can take you the entire way without having to change it. If you must switch gears, do so quickly so as to not lose wheel torque. Automatic transmissions are recommended over a manual, since they don’t require clutch operation.
4. Stopping the vehicle: Applying the brakes will sink the vehicle into the sand. Therefore, let the vehicle roll to a stop, or better yet, stop the vehicle on a solid surface which will make starting o on a hill possible.
- Driving Tips
1. Gear selection and speed: L4 (LL) is the appropriate transfer lever position for driving over steep rocky terrain. Drive at a moderate speed, since driving at higher speeds may shoot rocks from the ground to the undercarriage of the vehicle, which may result in vehicle damage. Also, the impact of driving over a ditch or hole may damage the tires, wheels and/or suspension.
2. Trail: For your safety, it is recommended you have a passenger in the front seat assisting the driver. Observe sharp rocks which may damage the wheel or puncture a tire. When driving over rocks, make sure these will not move out of place. If a rock moves from the tire to below the vehicle when driven under, it may lodge under the chassis or may cause a rollover.
3. Tire pressure: Lowering tire pressure is an option when more traction is required. However, higher tire pressure will be needed more often to minimize damages from the rocks to the tires and wheels.
4. Steering operation: When preparing for the possible steering kickback caused by rocky terrain, place your thumbs over the steering wheel. You must keep a firm grip at all times to avoid moving o-course from the originally selected path.
- Driving Tips
Inspecting the terrain
1. Since dangerous objects may be below the visible slow, walk over the surface to test it before driving.
2. The maximum amount of slow you should drive over should just reach the lower portion of the differential. If the surface consists mainly of fresh, unpacked snow, the maximum height may reach the lower portion of the bumper. Anything deeper will require you to remove part of the snow from the path and then continue.
3. The quality of the snow will change it’s reaction to a vehicle. Vehicles may become more easily stuck in wet, icy snow patches.
4. Some vehicles will be more stable when driving in trails left by other vehicles.
Starting the vehicle
Releasing the clutch pedal quickly will result in a loss of traction. To start the vehicle, release the clutch slowly and gently. Also, select a higher gear. For automatic transmissions, simply release the brake pedal to set the vehicle in motion.
On a snowy or icy surface, drive at no more than half the recommended speed limit.
1. Use specially designed tires for driving on snow*. Having excesscondence when driving a 4×4 over snow may result in the vehicle getting stuck or having an accident. Once the vehicle loses traction there is no dierence between a 4×4 and a 4×2 vehicle.
*Snow tires: These are tires specically designed for driving in snowy or icy conditions. The main benet of this tire is the ability for it to remain elastic under cold conditions, which improves its traction. The tire’s tread is specically designed for smooth, comfortable driving over snowy and/or icy roads.
2. Making tight turns is dangerous. If the vehicle begins to skid, the vehicle will travel to either the lowest portion of the road or towards the tire which began slipping. Slowly press the accelerator (do not release it) and steer in the opposite direction to regain control.
3. When the vehicle begins to loose control while turning, drivers tend to over-compensate. Drivers must be aware of this trend, since the vehicle may suddenly regain traction and then begin to severely skid out of control.
1. Test the brakes to see if a wheel lockup is possible, but in a secure, open area. Knowing this limit allows the driver to make delicate maneuvers under high-pressure situations.
2. Vehicles equipped with snow tires or chains have less horizontal grip than conventional tires. Therefore, driving speed must be reduced before making a turn.
3. The roads immediately before an intersection or corner tend to be slippier than normal, since many vehicles have previously applied the brakes in these places before.
Begin your ascent observing the vehicles in front of you and try to not stop when climbing. If you are forced to stop and cannot restart, return to the base of the hill and start your climb from the beginning.
Switching gears or a sudden deceleration when driving downhill should be avoided, otherwise the vehicle may lose traction. Select a low transmission gear and allow the engine to do the braking for you.
- Tire Chains
1. There are metallic snow chains and non-metallic snow cables. Snow cables are lighter, and are easier to install and transport. On the other hand, metal snow chains are heavier and are more dicult to install, although they are more economical and are easier to repair should they become damaged.
2. Snow chains or cables should be installed as soon as snow begins to fall continuously. If other vehicles are driving with them, that is a good sign to install them. In the case of a 4×4, install the snow chains on the tires which are supporting the greatest amount of weight. For driving over deep snow or driving downhill, install the chains on the front tires. When driving uphill or over more compact snow, install them on the rear. If chains are installed on the front tires they may cause damage to the inner portion of the wheel, the axle or the brake lines. When installing chains on the rear tires, they may a ect steering performance, but allow for easier correction. If the vehicle becomes stuck, the chains may be removed and placed on the front tires to obtain more traction. Placing the chains on the front or rear wheels is a decision which should be made depending on the situation, but the rear tires are generally the norm.
- Additional advice for cold weather driving
Snow accumulation on the vehicle
When driving, snow attached to the fenders may a ect steering, and visibility may be reduced by snow on the head lamps. Correct these possible issues by occasionally checking the vehicle.
Try to not bring snow into the vehicle
Be careful not to bring snow into the vehicle’s interior through your shoes and clothing, since it may make the pedals slippery or icy and may even freeze the pedals when the vehicle is parked.
1. Avoid parking in areas with strong winds snow, or where a large snowfall may occur if possible.
2. When parking for extended periods of time, take the time to clean all the snow o of the vehicle before driving again.
3. A way to assure the vehicle’s battery is maintained is by disconnecting it from the vehicle. When in extremely cold conditions, removing the battery altogether and storing it in a warmer location is also an eective measure. Changing the vehicle’s orientation when parked or putting cardboard or towels over the vehicle’s hood are not eective measures.
4. To avoid the vehicle’s brake pedal from freezing, park the vehicle without using the parking brake. Leave the vehicle in gear, either in rst gear or in reverse.
5. To avoid the windshield wipers from freezing to the glass, raise the wiper arms, avoiding the blades from touching the windshield.
6. To avoid the door locks from freezing, lubricate the lock with a non-corrosive grease or oil where you insert the key.
If you attempt to force the door open after it has frozen, you may damage the door and/or frame’s rubber seal. Apply heat with moderately warm water and wait for the door to unfreeze.
Fuel will freeze below 10° Fahrenheit (-12° Celsius), blocking the fuel line. Leave some space in your fuel tank before arriving at your destination, which will allow you to rell the tank with anti/freezing fuel if it is available.
When the battery does not have sucient uid, stored electricity will drain more rapidly and starting in cold weather becomes more dicult.
Amount of radiator fluid and antifreeze
Avoid freezing of the cooling system by using LLC Antifreeze liquid.
Windshield washer fluid
Driving in snowy conditions uses more windshield washing uid than usual. Make sure the reservoir is full.
Starting the vehicle
When a vehicle has been parked for an extended period of time, the radiator uid may freeze slightly, even when antifreeze is used. If the vehicle is started before the frozen liquid thaws, the little liquid remaining in the radiator may boil and rupture a hose. Allow the engine to heat up before moving the vehicle. Wait until warm air comes out of the air conditioning system or the temperature gauge begins to move.
Appropriate Seating Position
Make sure you are in a proper seating position, which is required for your driving safety, as well as allowing you to respond rapidly and correctly to any change in driving conditions. Make sure the vehicle is as stable as possible is one of the most important things to look for when driving over dicult terrain. As useful tip is to slide the seat forward and place the seat back in a more upright position than normally used once you enter a dicult terrain. This driving position will not only give you improved driving visibility, but also assure a three-point seating position with the left foot, knee and right hip, which allows you to maneuver the vehicle quickly and precisely.
Mirrors are your second set of eyes. Tips for proper adjustment
When additional attention is required on a path when driving over dicult terrain, the left and right side mirrors should be adjusted slightly downward in order to allow you to see the rear wheels and the drive line.
Close all windows
If the situation allows, all windows should be completely closed to avoid the entry of foreign objects and to serve as a precaution in the event of a rollover. It is extremely dangerous to take your head out of the window when driving in reverse. However, a small opening of two to three centimeters can be useful in allowing the driver to hear changes in engine conditions as well as slipping tires due to a loss of traction.
Correctly Handling the Steering Wheel
When driving o-road the use of the steering wheel is basically the same as when driving over paved roads. A lot of attention should be paid when driving over bumpy roads since potholes and bumps can make the vehicle tilt and/or kickback from the steering wheel. If the steering wheel is not held properly, the driver can suer broken fingers or sprained wrists.
Soft and precise braking control
Roughly operating the brake pedal can lead to steering lock and sliding of the vehicle when driving over wet, frozen surfaces, as well as sand and gravel, thanks to driving over low friction surfaces with a heavy vehicle. Special care should be taken when driving down steep slopes which are actually more slippery than expected. In this case, the pedal should be pressed softly. In principle, you should do most of your braking with engine compression and use the conventional foot brake as a secondary measure.
Always drive carefully!
In general terms, a 4WD vehicle is heavier than its 4×2 counterpart, due to additional drivetrain components. If you attempt to drive a 4×4 vehicle in the same way you would a 4×2 vehicle, you could end up with a longer braking distance or less responsive acceleration when starting o or overtaking another vehicle. In addition, the vehicle’s center of gravity is placed higher due to the additional necessary road clearance which is necessary for driving over dicult terrain. High G-Forces can aect the vehicle’s stability when turning
due to a larger side imprint. In order to properly maneuver with the unique 4×4 features mentioned above, you must always drive with caution and not be overly aggressive. Avoid any sudden operation such as quickly accelerating, sharp turns, stopping or shifting gears suddenly, since you may cause an accident or become stuck.
How does a 4×4 work?
Different mechanisms and features of Four-Wheel Drive (4WD) systems
Most vehicles today are two-wheel drive vehicles, with traction either at the front (FWD) or at the rear (RWD). 4WD vehicles however have the ability to have traction on all four wheels, which allows for the vehicle to move even if one wheel has no grip. A vehicle with these features generally has more traction than a FWD or a RWD vehicle and provides greater stability in dicult terrain (such as in sand, mud or other slippery surfaces).
The use of 4WD vehicles
In this guide, we’ll focus on the two most common Four Wheel Drive systems: Part-Time 4×4 and Full-Time 4×4.
In a Part-Time 4×4, a vehicle is generally moved through traction received at the rear axle (RWD) until the driver engages the Four Wheel Drive transfer (o -road gearbox). There are two types of transfer controls for a Part-Time 4×4.
1. Lever Type transfer : Move the transfer lever from “H4” to “L4”.
2. Electronic Switch Type transfer: By pressing a button or moving a switch.
Shifting into 4WD in older vehicles generally requires the vehicle to be at a complete standstill. However, most modern 4×4 vehicles allow you to engage 4×4 mode without having to stop the vehicle. This is known as shift on the fly. Because of this, confirm the appropriate procedure for your vehicle by reviewing the owner’s manual in order to avoid damaging the transfer case and a potential accident. When the vehicle shifts into Four Wheel Drive, an indicator light will usually light up on the instrument panel, which conrms that 4×4 mode is engaged. However this light burn out over time, which is why the best way to know if the vehicle has traction on all four wheels is by actually driving it.
Full-Time or Permanent 4×4
In a Full-Time 4×4, all four of the vehicle’s wheels are permanently connected to the engine. Here, the use of the transfer lever is not to engage or disengage the 4WD, but rather optimize the 4×4 system according to each drive surface.
Driving Fundamentals for Difficult Terrain
LSD & Center Locking Dierential
Some vehicles come equipped with an LSD or Limited Slip Dierential. In the case of a rear-wheel drive vehicle, if the rear wheel begins to spin due to loss of grip, the limited slip dierential automatically transfers a small amount of engine torque to the opposite wheel, thus avoiding getting stuck thanks to the single wheel with no grip. Some vehicles come equipped with front or rear Limited Slip Dierentials, depending on the type of traction available on the vehicle.
1. This type of dierential lock us useful when one or both wheels on the same side of the vehicle (left or right) are spinning due to lack of surface grip. Before using a diferential lock, the driver should first engage traction to both axles (H4 or L4 in Part Time vehicles, HL in Full-Time vehicles).
2. Front and rear differential locks should never be used in conditions others than those described previously, since this could make driving, and especially turning, very dicult. This is especially true if a center differential is locked and not only the rear, which will cause the vehicle to spin suddenly during acceleration or braking.
- Engine braking: by removing your foot off of the accelerator, the engine canmaid in braking the vehicle. The resistance caused by the transfer case and transmission slows the engine speed, reduces the vehicle’s speed and effectively slows the vehicle. This is also known as “braking through engine compression”.
Braking when turning with a 4×4
When driving in 4WD mode, turning sharply will give the driver the impression that the vehicle’s differentials are locked. This is known as the tight turning phenomenon and is caused by the difference in speed between the front and rear axles. Although this doesn’t mean the vehicle is malfunctioning, if this is done on a road with good traction, it can cause premature tire wear and damage the drivetrain. This can be avoided by simply driving without the center differential locked (HL or LL).