A turn-up device (40) for making a molded body of an air spring on a mechanical drum (30) having expandable end portions (32). The device (40) comprises a support member (42), a plurality of turning arms (44) pivotally mounted to the support member (42), and a sleeve (46) having a plurality of fingers (72) each provided with a cam surface (74). The turning arms (44) are movable between radially outer and inner positions and are biased to the radially inner position. The turning arms (44) are positioned and sized for insertion into the spaces between the segments of the expandable end portion of the drum (30). The support member (42) is movable towards the end portion (32) of the drum (30) relative to the sleeve (46). The turning arms (44) each include a roller (62) that engages the respective cam surface (74) of the respective finger (72) when the turning arm (44) is in its radially outer position. Upon continued movement of the support member (42) towards the drum (30), the roller (62) of each turning arm disengages the respective cam surface (74) of each finger (72) and releases each turning arm (44) to its radially inner position by virtue of each turning arm (44) being biased to its radially inner position.