Abstract: A shaft retaining apparatus has been discovered for retaining a reciprocating shaft within a housing. The shaft retaining apparatus includes a shaft (16) having an outer retainer engaging surface (28) and a shaft housing (18) having a bore for rotatably receiving the shaft and at least one housing protuberance (36) disposed on a shoulder (32) on the housing. A shaft retainer (20) includes a tubular portion (40) and a flange portion (48) disposed at one end of the tubular portion. The flange has at least one retainer protuberance (44) projecting toward the shaft housing. The at least one retainer protuberance has a predetermined height and arcuate length such that it contacts the housing protuberance upon press fitting and disengages thereafter upon rotation of the shaft within the housing, thereby establishing a predetermined clearance between the retainer and the housing.