This shaft is part of the shafting system used in the power steering equipped John Deere two cylinder tractors. This shaft is driven by the fan gear which is pressed onto this shaft. The splined end of the shaft will be "coupled" by spline couplings to an intermediate coupling shaft inside the fan shaft tube. Our shaft is made like the original except for two changes. We use a higher medium carbon steel with flame hardened splines. We then cut our retainer grooves more square and use modern heavy retainers instead of the older style Eaton snap rings. This gives a better, more easily assembled shaft assembly. We provide the retainers and a square key for the fan drive gear. There are two lengths of fan drive shafts. We make both types. This is the shorter, more common version. When rebuilding a 720 system, check carefully your serial number breaks and the casting part numbers of the fan drive housing