What was found
DURING CRUISE CREW RECEIVED GEN 4 OFF BUS AND GEN4 BRG FAIL MESSAGES. CREW FOLLOWED CHECKLIST AND SUBSEQUENT LANDING PERFORMED WITHOUT INCIDENT. MAINTENANCE EVALUATION FOUND #4 GENERATOR HAD A BEARING FAILURE WHERE INSTEAD OF SHAFT SHEARING AS EXPECTED, THE CASE BROKE AT THE COOLING CUTOUT OUTLETS NEAR THE FLANGE CAUSING THE MAIN BODY OF THE GENERATOR TO ROTATE AND TWIST THE POWER ELECTRICAL CABLES UNTIL THE GENERATOR SHAFT FINALLY SHEARED. THE GENERATOR AND 3 MAIN ELECTRICAL POWER CABLES AND OTHER ELECTRICAL WIRING REQUIRED REPLACEMENT. REVIEW OF THE GENERATOR OVERHAUL DOCUMENTS REVEALED CONCERN THE CMM USED WAS AN OLD REVISION OF REV. 6 INSTEAD OF THE CURRENT REVISION OF REV. 12.