Hi there thundergyrrl,
Sorry that you are facing issues with your WD drive.
🙁
Sometimes, clicking sounds, could e result of not enough power supplied to the drive. Have you tried attaching the drive with a different USB cable? In not, you can do so. You can even use one of those Y type of USB cables.
If this does not work though, you need to keep in mind that:
- The model is most probably hardware encrypted. This means that you will not be able to recover the data in case the drive is taken out of the enclosure. It may have some proprietary connectors as well.
- In case you open the drive up(not the enclosure), you will expose the platters to dust contaminated environment.
- It seems that there is something physically wrong with either the drive itself or the enclosure. This is why the software solutions didn't work.
In case the drive is still under warranty, you can just contact WD's Support and RMA the drive.

I guess it will not hurt to contact WD's Data Recovery Partners and see what they will tell you(in case you haven't done that yet).
It may be a good idea to wait for some more data recovery ideas as well.
WD's Support:
http://products.wdc.com/support/kb.ashx?id=tpYeDc
WD's Data Recovery Partners:
http://products.wdc.com/support/kb.ashx?id=KgqWn4
Hope this will help,
D_Know_WD