A method and apparatus for vertically lifting and supporting a main wedge of a Boiling Water Reactor (BWR) jet pump restrainer assembly, to ensure that the wedge is no longer contacting a restrainer bracket of the restrainer assembly. A main wedge clamp with an upper and lower clamp jaw is used to attach to the upper support of the restrainer assembly, the lower clamp jaw being fashioned with a prong or prongs that fit underneath the crown of the main wedge and provide the vertical lift for the main wedge.