Abstract: For use in rotating a bushing of an assembled track, wherein the bushing is press-fitted into apertures of a pair of links, first and second members are securable to one and the other of such pair of links, and a rapidly extendable and retractable cylinder interconnects the first and second members for providing a vibratory motion which, for optimum results, should be at resonant frequency to the links while rotational torque is being applied to such bushing.

Abstract: A controllably deformable fastener assembly has a fastener, clamping means, and a crushable element. The fastener has a threaded shank portion, a head portion and a shoulder portion on the head portion. The shank portion is of a material having a preselected tensile yield load. The clamping means is provided for screw threadably receiving the shank portion of the fastener, including a shoulder portion that is movable towards the shoulder portion of the fastener for securing a first member to a second member. The crushable element is disposed therebetween and is of a material that is controllably plastically deformable at a preselected load which is less than the preselected tensile yield load of the shank portion of the fastener.