Unmounted hard drive times out ejecting or mounting
Looking at the total size of the disk I suppose you are hit by the 2.2 TB limit of MBR partition tables. 


  Since block addresses and sizes are stored in the partition table of an MBR using 32 bits, the maximum size as well as the highest start address of a partition using drives that have 512-byte sectors (actual or emulated) cannot exceed 2 TiB−512 bytes (2,199,023,255,040 bytes or 4,294,967,295 (2^32−1) sectors × 512 (2^9) bytes per sector). Alleviating this capacity limitation was one of the prime motivations for the development of the GPT.


So repartition the disk with a GPT partition table.