A power axle for assisting an automotive vehicle in ascending and descending steep slopes and grades includes an electromagnetic motor mounted to one floating axle of the vehicle, a junction box mounted to and electrically connected to the electromagnetic motor, a DC/AC power inverter mounted to the cab interposed between and for electrically interconnecting the vehicle's battery to the electromagnetic motor for powering the motor from the battery and control switches mounted on the dashboard and which include an on/off switch and a speed control dial for regulating and controlling the interaction and engagement of the electromagnetic motor with the floating axle of the vehicle.