The tractor PTO shaft has two parts. One is the main shaft, and the other is the secondary shaft. Together, these parts propel the tractor forward and help it move equipment. They have safety shields on both ends and vary in length and shape. PTO axles are most commonly used on two-speed tractors.PTO shafts are an important part of a tractor because they help transfer power from the tractor’s engine to connected equipment. They allow small tractors to do many different jobs. They can be attached to the front, back or side of the accessory. The power of the PTO shaft powers the attachment. They also work with different types of attachments, so you should refer to your tractor’s manual to find out which attachment is best for your tractor.