As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) TAILROTOR GEARBOX BEVEL GEAR - LOSS OF TORQUE ATTACHING IT TO THE OUTPUT DRIVE SHAFT - ALL THE BOLTS WERE LOOSE CAUSING EXTREME BACKLASH IN GEAR SET. FOUND DURING GEARBOX REMOVAL/INSTALLATION. THE INPUT PINION, OUTPUT BEVEL GEAR, OUTPUT SHAFT ALL SCRAPED.