Helps the driver to select any forward or reverse gear.
Adjust speed of the tractor from the engine crankshaft to the drive shaft.
Helps to alter the speed ratio.
Enables the power from the engines to be more easily applied to the work done by the tractor.
Enables the driver to stop the tractor movement without stopping the engine or without foot pressing on the clutch all the time.
Mohaissack answered the question on October 10, 2017 at 11:18