A farm jack is not a standard car jack and is called a farm jack since it’s mainly used with farming equipment such as tractors and jeeps. These jacks are larger by far than any standard jack and are used to lift extremely heavy weights high off the ground. Farm jacks are best used on vehicles with big wheels and for raised or tall vehicles.

Farm jacks come in a number of models, but the basic range is from 48” to 60” in height. These jacks all use the same mechanical lifting principles and are made from similar materials. Essentially, the lifting system is a cast steel socket that drops over the rack. The rack has a long series of holes in which steel lifting pegs are secured in place when the jack has reached the preferred height. 

At the bottom of the jack is the lifting mechanism, this includes the “foot” or “toe” which holds the weight of the load. The lever is usually a long pole of steel that is set into a receiving lever that gives you the ability to push the jack up the rack and is locked in place using the pins.

All jacks come with a “reversing catch,” remember that this must never be touched until you are ready to release the load when it is on the ground. The reverse catch basically separates the lever mechanism from the rack, and if the pins are not in place, the jack mechanism will fly down the rack. Take heed also that if the handle is in place, it will go up and down with speed, and is extremely dangerous. Imagine a chopping mechanism, that’s what you get here. So always make sure the reverse catch is locked into its place, and only use it when you need to release the tension in the lowest stage of the operation. That means when you have lowered the jack to the ground, but still have that initial tension from holding the vehicle frame to the jack. 

Operating a Farm Jack

1. If possible, wear gloves. Farm jacks are large heavy steel and cast iron objects that will abrade, cut and bang your exposed hands. Also, most people don’t clean their jacks, so it is most probably covered in grime.
2. Hopefully, you have a stable surface, if not, create one using rocks or whatever you have in the field. If you are in the stable, or on a road surface, just place the base or toe on the road surface. I always suggest that anyone that uses a farm jack have a piece of 2×4 hardwood block, or a similar sized block of aluminum as a firm base for the jack in muddy, sandy and wet terrains.
3. Now turn the knob of your jack to the lifting position, this means that when you place the lever in its lock, you can lift it up and down with ease. 
4. Position the jack in place and lower the handle down to the floor. Make sure that you located a strong and secure position under the vehicle you want to lift. Incorrect placement can damage your car. One of the best locations is under the axle. If you are using the jack to uplift an obstacle or post, position it as close to the center of the object as possible.
5. Once in position start to “jack” your jack by levering the lever up and down so that the vehicle or obstacle reaches the height you need for performance.
6. After completing the operation, turn the direction lever or knob to down. Lower the jack down using the lever, and go all the way down until it has reached the floor. 
7. Now you can use the reversing catch if required.

Conclusions

A farm jack is a perfect heavy duty tool for off-road performance, but make sure you have a proper jack harness since these are heavy and long objects. Also, as mentioned above, after use, when you have finished your trek. Maintain your jack by giving it a thorough cleaning and grease the mechanical moving components.