As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UPON DISASSEMBLY OF GEARBOX AND INSPECTION OF PARTS DUE TO METAL, FOUND PINION GEAR HAD EXCESSIVE GALLING ON GEAR TEETH. POSSIBLY DUE TO IMPROPER MESHING OF GEARS. SECONDARY DAMAGE: T/M GEAR P/N 6893673 S/N NN143321. TT: 15,65.3 HOURS. SPALLING ON GEAR TEETH.