PTO Control Types

When you first purchase a truck or tractor with power take off, you must as a part of evaluating your purchase, determine which type of PTO control you desire.  There are a few different types of Power Take Off ( PTO ) control, each with certain advantages and prices.  Here is a basic overview

The most common type of PTO control is the direct transmission PTO which is where the PTO is taken directly off of the transmission, and can be engaged or disengaged via the tractor's clutch. While this is the simplest and most economic of ways to drive the power take off, it has the disadvantage that the PTO is driven only when the tractor is driven, limiting the user use of the PTO to change gears while the PTO is operating. A slip or overrunning clutch is required in this type of arrangement to prevent the accelerated mass of the driven equipment from in turn driving the tractor itself when the tractor clutch has been disengaged.

Some tractors have live PTO which in essence is a two stage clutch. This type of clutch is capable of disengaging just the engine or both the PTO and engine itself if the clutch is fully pressed. With this design the user has the benefit of being able to change gears on the tractor engine without affecting the speed of the PTO, which is beneficial especially in applications such as chemical spraying or watering.

Additionally, some tractors have independent PTO, which allows complete control of the PTO driven pump or equipment completely independent of the engine itself. This can be accomplished mechanically or with hydraulic controls. PTO equipment is offered in both mechanically driven types with splined shaft inputs and in hydraulic arrangements that can be driven by means of a hydraulic PTO control.