What was found
AT FL330 AND APPROX 1.5 HOURS INTO THE FLIGHT THE CREW BEGAN TO NOTICE AN AIRCRAFT VIBRATION. THE AIRCREW ISOLATED THE VIBRATION TO THE NR 2 ENGINE. THE VIBRATION BECAME EXCESSIVE AND THE CREW ELECTED TO PLACE THE NR 2 ENGINE IN IDLE POWER AND DIVERTED TO ANOTHER AIRPORT. AT 20 DME FROM THE AIRPORT THE AIRCREW ELECTED TO SHUT THE NR 2 ENGINE DOWN DUE TO THE VIBRATION INCREASING. AN EMERGENCY WAS DECLARED AND THE AIRCRAFT LANDED. INVESTIGATION REVEALED THE STARTER-GENERATOR HAD FAILED. STARTER-GENERATOR WAS REPLACED AND AIRCRAFT RETURNED TO SERVICE. (M)