Expanding the dvr expander

Has anybody tried to put an larger hard drive in an dvr expander with any success. I have and dvr expander that was used with an cox cable 8300 box, and I have now transferred over to direct tv. I would like to know if it is feasible to upgrade the expander with an 2tb wd hard drive. If so, do you think there would be any cooling issues with the newer type hard drives.

Did you ever get help with this?