If you have to recover data from a large size drive (2-3+ TB) do not use a USB dock. Hook the drive up internally on a recent model (preferrably UEFI based) desktop computer. If this is impossible then an eSATA adapter might work, but I am not sure.
Use a recent operating system (Vista or later, or recent version of Mac OSX) and see if you can read the drive. If the full partition comes up at the right size, you can use standard OS-based tools to recover data. If the partition is not the right size, or there is no partition at all, you can use testdisk from within the OS to scan the drive and try to recover the partition.