A reciprocating saw includes a housing assembly and a motor positioned within the housing assembly. The motor includes a pinion. A drive mechanism is positioned within the housing assembly and includes a gear driven by the pinion, a hub coupled to the gear, a spindle, and a connecting rod. A clutch assembly is coupled to the drive mechanism to selectively transmit drive force form the gear to the hub. The clutch assembly includes a first disk coupled to the gear, a second disk coupled to the hub, a biasing member, and a threaded fastener. The biasing member is positioned between the hub and the gear to bias the first and second disks into frictional engagement. The threaded fastener extends through the gear and threadably engages the hub to couple the hub to the gear. Tightening the threaded fastener pulls the hub toward the gear to preload the biasing member.