Abstract: An air actuator has a pair of axially spaced end members and an intervening elastomeric flexible sleeve extending therebetween which forms a fluid pressure chamber. An annular clamp ring having a smooth inner diameter coacts with an annular wall on the end cap having an outer diameter with annular indentations formed therein to clamp the ring on the end cap. The annular wall defines clamping surfaces in between and adjacent to the annular indentations. The annular indentations form a series of pinch areas with the intervening sleeve, which sealingly clamp the sleeve therebetween. The indentations receive portions of the sleeve and change the direction of reinforcing cords within the sleeve. The clamp ring abuts against a radially extending surface or shoulder of the end cap to reduce axial movement of the ring during operation of the air spring.