You need to replace the disk. It is little-known knowledge that external disks in enclosures are sub-standard in quality when compared against their desktop cousins.
A disk with extra vibration is only going to kill its bearings sooner than a non-vibrating disk. Maybe it will outlast the warranty, maybe not.
Other disks are vibration free and quiet, why should yours be any different? Afterall, you are paying good money for it. Why settle for a sub-standard product?
