External WD Elements drives on Linux systems

I have been using two WD Elements 2TB drivers with ext4 for a while, the only problem I have is that they don’t ever go into sleep mode while mounted. I haven’t been able to find a solution for this problem anywhere, so this is kinda my last hope.

Does anyone have a clue hot to make WD Elements 2TB drivers enter sleep mode on inactivity while still mounted on Linux?

Look at the drive specs Linux isn’t a suppoted OS that is probably the problem,

Joe