An auxiliary power unit is composed of a gas turbine engine, a gearbox, and a gearbox driven generator. A mount bracket is mechanically attached to the gearbox. The bracket is for connecting to an aircraft strut system. The aircraft strut system connects to the aircraft structure. The mount bracket has an upper mechanical attachment point and a lower mechanical attachment point to the gearbox. The gearbox includes an oil reservoir, and the lower attachment point is beneath the oil level within the oil reservoir such that said lower attachment point will be cooled by oil in the oil reservoir.