As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE PILOT NOTICED DURING CRUISE FLIGHT THAT THE HELICOPTER DEVELOPED AN UNUSUAL VIBRATION. IMMEDIATELY DIVERTED TO THE CLOSEST AIRPORT. FOUND THE LT AFT MAIN ROTOR GEARBOX MOUNT WAS UNSERVICEABLE DUE TO GLYCOL BEING RELEASED FROM THE BELLOWS. MOUNT WAS REPLACED AND THE ACFT HAS BEEN RETURNED TO SERVICE WITH NO ADDITIONAL DISCREPANCIES.