If they crank out with 2 scissor type arms you can possibly remove the stop between the 2 arms if once the windows open further the 2 glasses don't grind into one another. I tried on mine, you have to drill out the rivets holding the crank & slide the arms out either end, shorten the spacer & put it back, but mine the upper & lower windows ground together too badly to be able to accomplish opening further, I only tried one window & decided to just live with them barely opening.
Danny & Linda
Sold our '13 Thor Redwood 36 FB
Currently RV & truckless