Movable wall panel system with self-plumbing panels

A movable wall panel system with panels that automatically plumb to account for slope or rotation of the overhead track. The system includes a cross beam within an interior volume of the wall panel that is connected to at least one trolley movable along the overhead track. The cross beam is pivotally connected to the frame of the wall panel such that the panel can pivot relative to the cross beam, for example within the plane of the panel width. At least one biasing member, such as a compression spring, is located between the frame and the cross beam to resist pivoting motion. In a preferred embodiment, a pendant of each trolley is provided with a pivot surface that engages an underside of the cross beam in weight supporting relationship. The pivot surface and the cross beam underside are complementarily structured and arranged to permit pivoting about the pivot surface of the cross beam and the connected wall panel frame, such as in a direction generally perpendicular to the panel width.