Ford Repair Questions? Ask a Mechanic for Answers ASAP
That crunching sound is the cables grinding around the shaft of the motor and gear. It's a common enough issue that I would recognize it. You DO need to get the whole regulator, it's not that expensive a part (considering you own a Bentley) but you will need to remove the side trims to access this mechanism- clean hands required!
The motor is fine- it is the regulator that you need. This will consist of a pair of side rails that have the window clips on them, and have cables routed to pull these clips up and down on both sides, going through a driver gear and spool in the middle where the motor mounts.