TL*THE CONTACT OWNS A 2007 INTERNATIONAL 9400I SEMI TRUCK. WHILE DRIVING APPROXIMATELY 65 MPH, THE CONTACT NOTICED SMOKE COMING FROM OUTSIDE OF THE VEHICLE. THE BRAKE PEDAL AND THE EMERGENCY BRAKE WERE APPLIED WITH FORCE. THE CONTACT EXIT THE VEHICLE AND NOTICED FLAMES COMING FROM THE REAR OF IT NEAR THE DRIVE AXLE. THERE WAS ALSO AN EXCESSIVE AMOUNT OF ENGINE OIL ON THE GROUND. THE CONTACT ATTEMPTED TO EXTINGUISH THE MASSIVE FLAMES. THE FIRE DEPARTMENT ARRIVED AND COMPLETELY EXTINGUISHED THE FIRE. THE CONTACT HEARD THE SOUND OF AN AIR LEAK FROM OUTSIDE OF THE VEHICLE TWO WEEKS PRIOR TO THE FAILURE. THE VEHICLE WAS TOWED TO A LOCAL REPAIR FACILITY WHERE THE REPAIRS CONSISTED OF THE REPLACEMENT OF BOTH FIRST DRIVE AXLES, TIRES, BOTH BRAKE DRUMS AND SHOES. IN ADDITION, THE TECHNICIAN DETECTED A SMALL AIR LEAK IN THE QUICK RELEASE VALVES. THE FAILURE MILEAGE WAS 461,785.