As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MECHANIC TURNED PROPELLER ON GROUND AND NOTICED GRINDING NOISE COMING FROM THE GEAR CASE. FOUND WORN BEARING ON TACH-GENERATOR GEAR ASSEMBLY. MX REMOVED AND REPLACED THE INTERMEDIATE HOUSING AND GEAR ASSEMBLY, ALSO REPLACED THE FUEL PUMP WHICH FIXED THE GRINDING NOISE ISSUE.