As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ENGINE WAS REMOVED FOR METAL CHIPS ON UPPER AND LOWER CHIP PLUGS. UPON INSPECTION OF GEARBOX PARTS, FOUND PINION GEAR GALLING AND TORQUE METER GEAR SPALLING. NOTE: METAL CONTAMINATION CAUSED DAMAGE TO OTHER PARTS IN GEARBOX. SUBMITTER SUGGESTED IMPROPER MESHING BETWEEN TORQUE METER GEAR AND PINION GEAR WERE THE CAUSE FOR GALLING AND SPALLING OF GEARS.