As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GOVERNOR WAS SUBMITTED FOR INSPECTION DUE TO AN ENGINE FIRE ON THE GROUND. DURING INSPECTION, THE DRIVE GEAR PN D 4718 WAS FOUND CRACKED IN THE DRIVE GEAR SPLINES THAT ENGAGE THE GOVERNOR DRIVE ON THE ENGINE. THE GEAR CONTAINS TWO CRACKS, ALMOST 180 DEGREES APART AND OVER .5000 INCH LONG. HAD THE ENGINE NOT CAUGHT FIRE, THIS GEAR MOST LIKELY WOULD HAVE FAILED IN SERVICE.