US Patent 7886534 Integrated hydrostatic transmission assembly

A hydrostatic transmission mountable to a vehicle frame as a unit. The hydrostatic transmission has a nose cup to which a motor module is mounted. Passageways in an end block connect the pump element and motor module in a closed loop. The end block also has passageways for connecting a charge pump to the closed loop for supplying make-up flow thereto. An isolation plug is provided for separating flow between two intersecting passageways in the end block.