Mine were making a "clunking" noise from day one. I asked for it to be examined and evaluated for warranty work by the dealer, but was assured that it was "Normal". On one camping trip, the noise became continuous as I was extending the landing gear, and it wouldn't lift the FW enough to separate the TV. I used a hydraulic jack to get the FW up enough to disconnect, and was able to reconnect and get it home. I disassembled the unit and found that the gear teeth were broken. What was more interesting was that one of the teeth looked like it was actually a manufacurer's defect. I assume the "clunking" was the noise being made everytime that tooth engaged the adjoining gear.
I decided to replace the whole system with a much more stout one so I wouldn't get stranded in the future.