Did you try reshaping the box? Curious if that worked for you?Thanks for this information! I was about to drop the belly cover on our 340rl to try and fix our crushed metal duct. I used a camera to see that our “U” shaped metal box is about half crushed. I may try what someone else did and insert something into that box and try to enlarge to opening. Ours has been this way since we bought it last September.
