Abstract: A piston and cylinder assembly in which the rear end of the piston defines an arcuate concavity opening in the rear face of the piston, a retainer having an arcuate configuration matching the arcuate configuration of the piston concavity is positioned in the concavity and defines a spherical socket capturing a spherical front end of the pushrod of the assembly, and a clip coacts with a circumferential groove on the interior surface of the concavity and an external groove structure on the retainer to fixedly secure the retainer to the piston and preclude displacement of the retainer and captured pushrod from the concavity.