What was found
THE NO. 1 TR DRIVESHAFT BEARING SLEEVE BECAME DISPLACED FROM THE NO. 1 TR DRIVESHAFT BEARING ASSEMBLY. THIS CAUSED A GAP BETWEEN THE TR DRIVESHAFT AND THE BEARING INNER RACE. DURING AIRCRAFT SHUTDOWN, THE DRIVESHAFT AND BEARING INNER RACE WERE MAKING CONTACT CAUSING NOISE AND VIBRATION. THIS WAS CAUSE FOR THE PILOT AND ON-SITE MECHANIC TO REMOVE THE COWLINGS AND INVESTIGATE FURTHER. ONCE EXPOSED, SIGNIFICANT WEAR WAS OBSERVED ON THE TAIL ROTOR DRIVESHAFT AT THE LOCATION OF THE NO. 1 BEARING.