As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ALTERNATOR ATTACHMENT BRACKET MOUNTING HOLES ELONGATED CAUSING THE ALTERNATOR FAN/FLYWHEEL TO GRIND AGAINST THE ALTERNATOR ATTACHMENT BRACKET LEADING TO ALTERNATOR FAILURE. THIS ENGINE WAS RECENTLY OVERHAULED AND HAD ONLY 80 HOURS SINCE OVERHAUL. THE FRONT BUSHING AND MOUNTING HOLE IN THE BRACKET WERE SERIOUSLY ELONGATED ALONG WITH ONE OF THE BOLT HOLES IN THE BASE PLATE OF THE MOUNTING BRACKET. THIS ALLOWED ENOUGH PLAY FOR THE ALTERNATOR FLY WHEEL TO CONTACT THE MOUNTING BRACKET.