This project all started because I noticed the plastic housing surrounding the FF motor was split. When I removed the housing I noticed that the crank and the plastic to which it was attached was cracked. This led to the the housing splitting.
I called Fantastic Vent Corporation (now owned by Atwood) and explained what had happened. They decided to send me a new one conditioned on me returning the old one so that they can try to determine what happened.
So, knowing that I would have to remove the old one, I decided to remove the vent in the bathroom and replace it with a FF as well. I chose the 6000RBTA model; it has no wall switch and was easily wired into the existing circuit. As you can see by the following pictures, it was time to replace the vent lid at the very least.
After a good cleaning, both FF's went in pretty smoothly.