As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT NOTE THE TAIL ROTOR GEARBOX WAS LEAKING. GEARBOX WAS CLEANED WITH SOLVENT AND AIR DRIED AND THEN GROUND RAN FOR 2-3 MIN. LEAKAGE AND CRACK WERE NOTED IN AREA DEPICTED IN DIAGRAM BELOW. LOGBOOK RESEARCH NOTED NO EVIDENCE OF DAMAGE HISTORY OR TAIL ROTOR STRIKE. CAUSE OF CRACK UNKNOWN. (K)