Making sense of key terms and phrases

Air-cooled engines:

One of two engine cooling processes (also liquid-cooled).  Aluminum fins cover the engine block and conduct the heat away from the cylinder.  Fan-forced air flows over the fins, which cools the engine by transferring the heat to the air.  Most often used for lighter engines that run on gasoline.

Ballast:

Added weight that serves as a counter-balance to a heavy payload.  Usually comes in the form of a “ballast box” and is attached to the rear of the tractor.  Often necessary when you’re using front-end loader applications.

Draft-load sensing:

A hydraulic system on the tractor that assists you in operating mounted implements more effectively.  A valve opens and closes in response to draft loads sensed on the tractor to automatically lift/lower an implement on the tractor.  Especially valuable when operating fully mounted implements on hilly terrain.  The implement will raise and lower to follow the ground contours while maintaining a nearly constant height or depth.

Gear-driven transmission:

One of two types of transmissions available for your tractor.  Very similar to a manual transmission in an automobile.  This type of transmission is connected to the engine through the clutch.  A combination of gears and gear ranges give you up to 16 speeds for operation.

Glow Plugs:

Used on diesel engines, especially smaller ones.  When a diesel engine is cold, the compression process may not raise the air to a high enough temperature to ignite the fuel.  The glow plug is an electrically heated wire that helps ignite the fuel when the engine is cold so that the engine can start.

HST (hydrostatic transmission)

Alternative form of power transmission from the engine to the drive train of you tractor.  Essentially, it’s a complete hydraulic system that provides a stepless adjustment of speed, torque and power.  Primary benefits are ease of use and quick response.  Functions most like the automatic transmission of your automobile.

Liquid/water-cooled engine:

One of two engine cooling processes (also air-cooled).  Fluid circulates through passageways in the engine and absorbs the engine’s heat.  The fluid then circulates through a heat exchanger (radiator) where the heat is transferred to the air blowing through the exchanger.  Diesel engines use liquid-cooled.

PTO (power take-off)

A “driveshaft” on the back end of the tractor that is used to power attachments or implements, e.g. rotary mowers.  The implement will have a matching power take-off shaft that attaches to the tractor, allowing it to draw power from the tractor’s engine.  PTO shafts rotate at either 540 rpm (rounds per minute) or 1000 rpm.

ROPS (roll-over protective structure)

A frame on open-station tractors that provides a safe environment for the operator in the event of a rollover.  All operators of tractors with a ROPS must wear seatbelts – which hold you with in the protective area of the structure. 

Shuttle transmission:

Allows easy shifting between forward and reverse on gear-driven tractors.  Especially useful in applications such as front-end loader work where frequent changes of direction are required.

Three-point hitch/linkage:

One of two methods of attaching rear-mounted implements to your tractor.  Consists of three attaching points (lift arms and stabilizers).  Working with the tractor’s hydraulic system, it’s an efficient means of lifting, lowering and pulling implements.

Wet disc brakes:

One of two types – common on tractors and other slow moving equipment.  The brake system is full-enclosed – useful in keeping out dirt or other containments.  The benefit is longer service life.  Other option is dry or mechanical.  Autos use a dry disc brake.