A securing assembly for connecting a drive assembly to a driven assembly of a catheter pump includes a motor housing, a flow diverter housing, and a flow diverter positioned within the flow diverter housing, wherein one of the flow diverter or the flow diverter housing includes a securement device. The securing assembly also includes a cap coupled between the motor housing and the flow diverter housing. The cap includes a central opening and a locking recess extending circumferentially about the central opening. Insertion of the flow diverter into the central opening causes securement device to engage the locking recess.