A center section/motor sub-assembly for use in a hydrostatic transmission includes a center section having a pump running face for interfacing with a pump, and a motor running face for interfacing with a motor. The center section and the motor are configured for the hydraulic separating forces of the motor to be reacted only into the center section. The center section has two internal passages between pump kidney ports and motor kidney port, and the motor kidney ports are raised in elevation relative to the pump kidney ports. The internal passages run parallel to each other as they rise in elevation. A hydrostatic transmission includes the sub-assembly enclosed by a housing, in combination with a pump and output shaft assembly. For installation, the output shaft assembly is configured as a separate component from the sub-assembly of the center section and the motor.