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Introductory paragraph: The most efficient and economical method of transmitting power from an agricultural tractor to an agricultural implement is through a power take-off (PTO) driveline. Most agricultural drivelines are designed for standard tractor PTO shaft sizes and speeds. Other agricultural drivelines are used internally in the agricultural implement. International Harvester introduced the first practical power take-off on a farm tractor in 1918. The 540-rpm PTO shaft, master shield, and drawbar relationship standard was developed by the Equipment Manufacturers Institute (EMI) and the American Society of Agricultural Engineers (ASAE) in 1926. In 1958 a standard for a 1000-rpm tractor PTO was published. In 1966 a standard was published for higher horsepower tractors. The ASAE S203 standard gives the details of the shaft dimensions and horsepower ratings, which have the following basic data...