What was found
(CAN) WITH AIRCRAFT IN CRUISE FLIGHT A (LT GEN TIE OPEN) ANNUNCIATOR LIGHT CAME ON. GENERATOR TIE RESET AS IAW CHECK LIST. SHORTLY THEREAFTER THE (LT GEN TIE OPEN) CAME ON FOLLOWED BY THE (LT GEN FAIL) LIGHT ANNUNCIATOR. AIRCRAFT SECURED IAW CHECK LIST AND AIRCRAFT RETURNED TO BASE. SHORTLY BEFORE LANDING THE AIRCRAFT EXPERIENCED LT ENGINE VIBRATION AND TORQUE FLUCTUATIONS AT LOW POWER SETTINGS. AIRCRAFT LANDED UNEVENTFUL. MAINTENANCE REMOVED SUSPECT GENERATOR AND FOUND END BEARING FAILED. GENERATOR REPLACED WITH OVERHAULED UNIT. AIRCRAFT GROUNDRUN, VIBRATION AND TORQUE APPEARED NORMAL. AIRCRAFT RETURNED TO SERVICE.