Direct drive. Spinny parts on the front of the engine. Front of the engine box is latched. Rear is hinged to the floor piece. Mine is a friction fit between the solid floor panels and the carpet.
In mine if I pull up the engine box I can lift up the floor. I'd pull the whole assembly up and put some carpet in the joint between the floor sections and push the middle back down to see if you can get it to bind up so it stays put without screws.
Seems weird that it would loosen up.