An automatic jack and wheel change system having at least one inverted jack driven by an electric motor permanently attached to the vehicle. The system may employ a jack disposed between the front and rear wheel on each side of the vehicle, or it may be equipped with a jack at each of the four wheels. The system also features a novel wheel and hub-axle assembly featuring a split axle whose length may be adjusted by operation of an electric motor. The hub has a plurality of arms extending from the hub in a star-shape, each arm having a finger at its free end. The wheel has a plurality of slots defined therein so that the wheel may be removed by aligning the slots with the arms on the hub and pulling the wheel off when the axle is extended, and a plurality of holes defined therein for receiving the fingers to lock the wheel on the hub when the axle is retracted. Both the motor for raising the jack and the motor for adjusting the length of the axle may be operated by remote control.