There are few bogging down situations that cannot be overcome with a high-lift jack, a spade and a strong back. The high-lift jack is without doubt the most valuable piece of equipment that an off-roader can carry. The jack discussed here is the American standard brick red-coloured unit that has been around for many decades. Although there are competitors’ jacks on the market, the ‘old favourite’ is virtually unbreakable and as long as it is kept well lubricated it is reliable. Unfortunately, more and more ‘off-road’ vehicles are being introduced with fancy curved plastic bumpers - impractical for bush work because of the absence of points where a high-lift jack can be used. There are cases where a vehicle has bogged down so comprehensively that jacking has been the only way out. Personally I would not venture to a place like the Makgadikgadi Pans in a vehicle not suited to jacking with a high-lift.
The jacking mechanism is used in the following way:
To lift a vehicle:
· Stand the jack under the jacking point and push the operating lever (small L-shaped lever on top of the lifting mechanism) down.
· Raise the jacking arm to the upright position to hoist the entire mechanism up the shaft so that the jacking foot is positioned under the jacking point of the vehicle.
· Adjust the jacking foot position exactly. Once this is done pull the arm down, thereby lifting and firmly locating the foot under the vehicle jacking point. Should the position need changing, lift the arm and readjust. Once satisfied with the foot’s position, lower the arm once again all the way down until the lifting pin enters the perforations in the upright shaft or ‘ladder’. It will click into place.
· Lift the arm to the upright position until a click is heard.
· Pull the operating lever into the upper position. It will click into place. The jacking foot will be held at that height. The vehicle is ready to be lifted.
· Hold the lifting arm with both hands. Gripping it firmly, pull it down once again until the pin locates and clicks into place. Lift the arm to the upright position and the second lifting pin locates itself. Continue until the vehicle’s wheel/s are off the ground.
To lower a vehicle:
· Raise the jacking arm to the upright position.
· Push the operating lever down.
· Gripping the arm with both hands, lower the lever so as to release the lifting pin. At this point the vehicle’s weight is in your hands. If you do not have a good grip and your weight is pressing down on the arm it can shoot up and cause injury. Have bystanders stand well clear.
· From this point jack the vehicle down by lifting and lowering the arm to its fullest extent.
WARNING: High-lift jacks can be dangerous.
The following simple safety advice must be heeded:
· when lifting or lowering a vehicle, hold the jacking arm firmly and with both hands. If released at the halfway point while under load it will shoot upwards with great force. It can smash teeth, cause concussion and the upward movement can release the lifting pin, causing the arm to drop by itself, starting an auto-jacking sequence which rapidly lowers the vehicle onto the ground. Once this auto-jacking has started it is too dangerous to try and stop it running its full course. Holding the jacking arm firmly is especially important when lowering a vehicle.
· When the jack is left unattended and under load, the jacking arm must ALWAYS be left in the upright position, clipped to the upright with the supplied wire clip. In any other position the jack poses a threat to anyone close to it.
· High-lift jacks are unstable. Never climb under a vehicle that is supported only by a high-lift jack. If you need to dig under the vehicle, do what you can before you jack it up.
Extricating Vehicles with a High-Lift Jack
The following situations demonstrate how the high-lift jack can be used to extricate a vehicle:
Jack and push
Your vehicle is stuck on soft ground with the axles grounded on a ridge; or you have dropped into a gully and two or more wheels are off the ground and spinning. If the ground is soft, place the jack on its broad base and jack up the vehicle, high enough so that the one set of wheels is higher than the ridge on which the axle has been caught. Now push the vehicle sideways. The vehicle will pivot on the jack and land on the ground with the wheels on the ridge, thereby clearing the axle from the obstacle. In some situations you may need to do the same with the both axles. Vehicles with spare tyres attached to the tailgate may have to either remove them or swing them clear as the falling jack may catch on them and damage the vehicle bodywork. If they are removed from a separate wheel carrying frame, the frame can be closed and used to protect the rear of the vehicle from the jack during this operation.
Jack and pack
Quite often the ground under the jack is soft and slushy and in these cases the jack and push method is not effective - the vehicle topples off the jack, the wheels dig into the mud or sand and the vehicle settles back onto its chassis. In this situation the best course of action is to jack up the wheels that are the most deeply dug in. Once this has been done find something to place under them - sand ladders, trac-mats, carpets, rocks, branches or logs - in fact anything lying around (in wet mud, grass seems to make matters worse). Lie items in the direction of travel so that the wheels can gain some momentum as they ride over them. If all four wheels are deeply dug in, this must be done to all wheels.
Before attempting to drive out think about the gear ratio to use. Should you use a gear ratio that is too low, the result may be wheelspin, and you may not only undo all your hard work but still have a bogged vehicle. Select the highest gear you think may work - try to remember the gear ratio that was getting you through difficulties beforehand, because once off the mats or logs you must be able to keep moving without a gear change. Selecting this gear ratio is critical and for each vehicle and for each situation it differs. The vehicle is then lowered and with everyone pushing, the clutch is let out gently with acceleration as smooth as possible. If the wheel spin occurs decelerate gently.
High-lift winch
The high-lift jack can also be used as a hand winch. Heavy manila rope must be used (the stretch of nylon rope renders it ineffective)
Proceed as follows:
· Remove the steel foot from the jack by sliding out the pin.
· Lay a length of rope from the bottom of the jack to the bogged vehicle. Do not attach it to the jack.
· Attach a cable or rope to the top of the jack and then onto the anchor.
· Position the lifting foot of the jack at its lowest position.
· Join a short length of chain to make a loop. Lay this loop across the rope at the bottom of the jack. Pass your hand through the loop and underneath the rope. Grip the chain and pull it through so that the chain loops around and grabs the rope.
· Using a D-shackle, attach the end of the chain you are holding to the hole in the base of the jacking foot.
The jack is used as if lifting a vehicle. As the rope is pulled taut, the chain grips the rope. When the jack is at its highest point, slacken the rope and chain, slide the jack back down to its lowest position, slide the rope through the chain, and begin jacking again. Although it is a time consuming process, it is often successful when conventional winching techniques have failed.
Care of a high-lift jack
If carried on the tailgate of a vehicle, some method of preventing the mechanism being clogged by dust should be devised such as the jack-nappy, a washable nylon sleeve that covers the mechanism. The ‘old favourite’ is criticised by its competitors for jamming under load. It’s a valid criticism and to prevent this the lifting mechanism must be clean and well lubricated. Have a can of Q-20 handy and at the first sign of slicking, give it a good spray. Despite this it remains, in my opinion, the best high-lifter on the market.
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