An arrangement for pivotally coupling an auxiliary axle frame to a vehicle chassis includes a pair of support brackets, each fastened to one of two opposite longitudinal rails of the chassis. Each bracket is coupled to its associated rail with a set of threaded fasteners extended through aligned openings in the bracket and rail. Each fastener is tightened to a predetermined level of tensile force, after which its movable components are welded together to positively and permanently set the fastener. Each bracket extends behind the chassis to support a rotational coupling device including a pin rotatable about a transverse axis. Opposite arms of the tag axle frame support clevis type coupling features at their forward ends. Each clevis type feature is integrally coupled to one of the pins. An actuator used to pivot the tag axle frame can be coupled to the chassis and frame through similar rotational coupling devices and clevis type features.