Modular hydrostatic transaxle for zero turn radius mower

1. Field of Invention A hydrostatic transaxle including first and second hydrostatic transmission modules and an axle drive housing. Each module includes a transmission housing, a rotating fluid pump and a rotatable fluid motor with the pump being of variable displacement and the motor being rotated at various speeds and in forward and reverse directions in response to changes in pump displacement. The axle drive housing contains first and second gear trains and a pair of axles. One of the axles is operably coupled to the first transmission module motor through the first gear train, and the other of the axles is operably coupled to the second transmission module motor through the second gear train. Each of the hydrostatic transmission module housings is detachably fixed to the axle drive housing.