Systems and method for cooling and lubricating power transmission systems include providing oil to an oil tube and then to a rotor shaft via the oil tube. Oil may also be provided through at least one channel defined in an end of the oil tube inserted into an annular region of the rotor shaft, through at least one channel defined in an end of the gear shaft and between the end and a shoulder of the rotor shaft and through at least one channel defined in side surface of the rotor shaft in a region of rotor shaft inserted into the gear shaft. Such systems and method can also include providing oil a fluid passageway in a bearing shim plate via an inlet tube. Oil may also be provided through a radial gap adjacent a bearing shim plate outlet and chamber defined in the bearing shim plate.