A transmission (380) for use with a powered surgical tool (44) is descrbied, the tool having a body (45) and a rotating drive spindle (68) that extends from the body. The transmission comprises a housing (382, 412) having at least one feature (418, 419) for releasably attaching the housing to the tool body (45) and at least one feature (385, 387) for releasably attaching another device (520) to the housing. The transmission further comprises a drive link (470) disposed in the housing (380, 382) for reciprocating movement in the housing, the drive link including a feature (478) for engaging a driven component (552) of the device (520) attached to the housing, and a gear train (430) internal to the housing (382, 412), the gear train configured for connection to the tool spindle (68) and connected to the drive link (470), the gear train adapted to convert the rotary motion of the tool spindle into motion that reciprocates the drive link. The housing (382, 412) is shaped so that, when the housing is secured to the tool (44), a section of the housing extends over a section of the tool. The drive link (470) is disposed in the housing so as to be disposed for reciprocating movement in the section of the housing that extends over the tool (44).