What was found
(CAN) THE NR 3 ENGINE WAS SHUTDOWN IN FLIGHT DUE TO LOW OIL PRESSURE CAUSED BY OIL DEPLETION. THE FLIGHT CONTINUED TO THE NEAREST SUITABLE AIRPORT WHERE MAINTENANCE DISCOVERED A RETURN OIL SCAVENGE LINE SPLIT AND LEAKING. FURTHER INVESTIGATION IDENTIFIED VIBRATION IN THE TRANSFER GEARBOX CAUSED BY A FAILED RADIAL MID SHAFT LOWER BEARING. THE OIL RETURN LINE, GEARBOX AND RADIAL SHAFT ASSY WERE REPLACED AND THE ACFT WAS RETURNED TO SERVICE.