Winches.

Winches are mounted on four wheel drive vehicles to recover bogged vehicles, to move heavy objects, and as the ultimate in 4x4 fashion accessories. They are usually mounted at the front, which is not the best position in many ways; it adds weight to a vehicle extremity and may require stronger springs, and it makes winching backwards difficult or impossible. Have you ever been stuck nose in? (The Foers system allows a centre mounted winch to pull to the front and the rear without rethreading the winch rope.)

Winching is potentially dangerous and some simple precautions should be observed. Keep innocent bystanders well away; a winch cable can snap and lash anyone in the vicinity. Do not use a snatch strap or other elastic device with a winch - you could be forming a powerful catapult. Use strong winching points - a stout tree (use a trunk protector), a buried ground anchor, or another vehicle. Use good equipment and discard damaged winch cable. Wear tough gloves to protect hands from frayed strands of cable. Make sure that the cable of a drum-winch feeds on in neat, uniform layers, but if you are feeding the cable in, keep hands well out from the winch fairleads in case they are snagged and dragged in.

Electric Winches

The electric winch is the most common type of winch. It is the cheapest and requires the least modification to the vehicle, so it it reasonably easy to remove it and transfer it to your next 4WD (a fact midnight spares are well aware of).

Electric winches can draw hundreds of amps which puts a great strain on the battery, alternator and the winch switch-gear if used for prolonged winching. They will operate if the engine is dead (e.g. in water) - until the battery is flattened. It is common practice to fit dual batteries to cope with the load and to leave the motor running while winching to keep the batter(y|ies) charging to some extent.

Failure of the switching solenoid is a moderately common fault. Remember to fit an interior isolation switch so that the winch cannot be started by mischief makers in your absence (possible even without the control unit).

PTO Winches

The PTO winch is driven by the engine through the gearbox and a power take-off unit, usually mounted on the rear of the transfer case. This kind of winch is ideal for prolonged heavy duty winching - the engine has plenty of power, even near idle speed, and there are no solenoids or electric motors to overheat. The gearbox and throttle can be used to give a wide range of winching speeds.

The main draw-back of the PTO winch is that it lacks the "fine control" of an electric or a hydraulic winch, and it cannot be used if the motor is dead, although some are fitted with a manual crank option for this eventuality. It is possible to drive the wheels, or the winch, or both by engaging the PTO, or the transfer case, or both but you do not have independent control of the winch and wheels except by de-clutching.
- 4wd.sofcom.com/4WD.html

Hydraulic Winches

A hydraulic winch is driven by a hydraulic motor, the fluid pressure coming from a hydraulic pump driven by the main engine of the four wheel drive. Hydraulic winches offer the fine control of electric winches with the endurance of PTO winches.

Traditionally, the hydraulic pump was driven from a gearbox or transfer-case PTO, but a recent development is to make use of the power steering pump already on the vehicle. Such a winch should not be expected to have the wind-in speed of a PTO-hydraulic unit under heavy load, but it should be considerably cheaper. Because the steering system is being modified, it would be prudent to check with the vehicle manufacturer re warranty, your insurance company re cover, and road-authorities re legality.

As of 1999 TJM had begun assembling power-steering driven winches locally.

Capstan Winches

The capstan winch is invariably driven by engine power. If mounted on the front, as on this 1948 Land Rover, the power usually comes from the front of the engine crank-shaft pulley via a dog-clutch. The rare, rear-mounted capstan winch is driven by a transfer-case power take off (PTO).

[4WD: picture of rear capstan winch, jpg]

A capstan winch is operated by taking a couple of turns around the capstan with the winch cable, and setting the capstan turning continuously. By varying the amount of tension on the tail of the rope, frictional forces can be controlled quite easily to generate the desired pull. The winch will hold the load if you make a couple of hitches with the rope tail around a strong point, such as the bumper bar. The winch rope is usually hemp, or synthetic rope these days. Steel cable can be used on a capstan but frayed strands are a hazard, and such cable wants to coil tightly after use, and is difficult to handle and store.

The great advantage of the capstan winch, over drum winches, is that it can pull at an oblique angle to the centre line of the vehicle. It does need two people to self-recover a vehicle with a capstan winch, but operating a drum winch solo is not very satisfactory either.

[4x4: picture of winch on amphibious Jeep or Seep, jpeg] Capstan winches were also fitted to Jeeps. A capstan has a distinctly nautical flavour and this kind of winch adorned the fore-deck of each amphibious Jeep or Seep (left, under the "red nose"). In this case the initial drive came by a belt from the crank-shaft pulley which could slip under heavy loads.

[4WD: picture of power take off PTO winch, jpeg]

This is the Nokken winch. It is mounted on the left-hand chassis rail and is driven by a PTO unit under the transfer case. It is in fact a capstan winch, the wire winch cable taking a couple of turns around the capstan closest to the camera, then being taken up on the storage drum farthest from the camera. This arrangement is compact and places the weight of the winch in the best position, close to the centre of the vehicle. The pulling power of the winch is not significantly reduced by the amount of cable on the storage drum, unlike simple drum winches. The cable can also be run out to the front or the rear of the vehicle.

Go to the Foers winch, TJM and offroad pages