As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(AUS) CRANKSHAFT GEAR INCORRECT PART. GEAR WAS NOT COMPLETELY MESHING WITH THE OIL PUMP DRIVE GEAR. PN 13S19648 FITTED INSTEAD OF CORRECT PN 13S19647. SUSPECT ENGINE HAD BEEN CONVERTED FROM EITHER AN IO-540 OR TSIO-540 MODEL, BOTH OF WHICH USED THE FITTED GEAR. PERSONNEL/MAINTENANCE ERROR. UNAPPROVED PART.