As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IN FLIGHT, AIRCRAFT LANDED WITHOUT INCIDENT. THE ALTERNATOR DRIVE END BEARING FAILED CAUSING THE ALTERNATOR ROTOR ASSEMBLY WITH THE DRIVEN GEAR TO EXTEND INTO THE ALTERNATOR DRIVE GEAR. THE MISALIGNMENT OF THESE TWO GEARS CAUSED THE ATTACH BOLTS ON THE ALTERNATOR DRIVE GEAR TO SHEAR. METAL FROM THE FAILED BEARINGS AND DAMAGE TO THE CRANKCASE CONTAMINATED THE ENGINE AND RUINED THE OIL PUMP GEARS AND HOUSING.