Abstract: Systems are provided for a coupling element. In one example, a system includes a coupling element comprising an elongated body, a first lobe coupled to a first end of the elongated body, and a second lobe coupled to a second end of the elongated body opposite the first end, wherein the elongated body comprises a top surface separated from the first lobe via a first recess and from the second lobe via a second recess.

Abstract: A self-steering assembly for self-steering wheels used on trucks carrying heavy loads includes a kingpin arm unit with a unitary adaptor collar at one end for mounting on a conventional tubular axle and a knuckle at the other end for retaining the clevis of a pivot link with a kingpin. The pivot link has a knuckle upon which is fixed a standard spindle unit having a steering arm secured thereto so that the assembly may be coupled to a similar assembly at the other end of the axle. A damper is pivoted at one end to the steering arm and at the other end to the axle. The self-steering assembly provides for the utilization of standard components in self-steering assemblies heretofore used only for steered axles.