1999 Keystone Springdale....slide problem

I bought this trailer cheap as it needed some work. Mostly fixed up now, but the small slide where the couch is seems to be loose. It is a manual slide, which I crank out from outside. It comes out no problem, but when I go to crank it back in, it seems to bind at the top. Its almost like the framework that it sits on has dropped or is broken inside. I have to crank it in and push the top part in as I crank it. Good thing I am tall...lol
When its all the way in, the top is still out an inch or so...and the whole thing seems to sit crooked

All I can see underneath is a large screw in the center that it rides on. The rest is covered by the black mesh. Anyone have any ideas how this all works before I rip it apart