As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING REMOVAL OF RENTAL TAIL ROTOR GEARBOX, IT WAS DISCOVERED THAT 1 OF THE DRIVE SPLINES FOR THE TAIL ROTOR SWASHPLATE WAS MISSING. THE RENTAL GEARBOX HAD BEEN INSTALLED FOR 40 HOURS AND WHEN IT WAS INSTALLED THE TAIL ROTOR SWASHPLATE HAD NO SIGNS OF WEAR. THIS TAIL ROTOR SWASHPLATE HAD A NEW TEE INSTALLED IN JUNE 2012.