A piston assembly, which may be part of a concentric slave cylinder for use in an automatic transmission, is provided. The piston assembly includes a piston and a piston cylinder disposed adjacent to the piston and having portions forming a receiving slot. A piston guide is attached to the piston. The piston guide has a main body portion and an alignment protrusion extending from the main body portion. The alignment protrusion is disposed in the receiving slot of the piston cylinder. The alignment protrusion includes a main alignment portion and a spring lever. The spring lever is separated from the main alignment portion by a gap. Compressible material is disposed in the gap.