A tongue-hitch structure for a pull-type implement may comprise a tongue locking mechanism. A work frame for the pull-type implement may comprise a vertically adjustable rear wheel suspension comprising an actuator for moving the work frame between a lowered, working position and a raised, transport position. The tongue-hitch structure may be adapted to allow vertical movement between the tongue-hitch structure and the work frame. A leveling arrangement may be coupled between the work frame and the hitch-tongue structure operable to prevent and/or allow vertical movement between the tongue-hitch structure and the work frame.