Transmission testing machine and method

A machine and method for testing a power transmission device are provided wherein the machine comprises a drive for driving the power transmission device and means for loading the power transmission device wherein the loading means comprises a power recovery system comprising a coupling having an input shaft and an output shaft with the shafts being free of mechanical connections therebetween, apparatus operatively connecting the power transmission device to the input shaft, and apparatus operatively connecting the output shaft to the drive, with the coupling having integral means operating to drive the output shaft at a speed which approaches but is less than the speed of the input shaft to thereby provide supplementary power for the drive in driving the power transmission device and with the system providing testing for any desired loading of the power transmission device with only the power necessary to overcome power losses in the machine thereby resulting in a substantial power recovery.