A surgical instrument includes a body, a shaft assembly, an end effector, a transducer assembly, and a loading assembly. The end effector is coupled with a distal end of the shaft assembly. The transducer assembly is removably coupled with the proximal end of the shaft assembly. The loading assembly comprises an actuator that is operable to couple the distal end of the transducer assembly with the proximal end of the shaft assembly. The loading assembly is operable to drive the transducer assembly through at least two stages of rotation to couple the distal end of the transducer assembly with the proximal end of the shaft assembly.
