A surgical instrument includes an end effector, a shaft assembly proximally extending from the end effector, and at least one translatable rack gear assembly coupled with the shaft assembly. The shaft assembly includes at least one elongate member connected to a select one or both of the end effector and the shaft assembly. The at least one translatable rack gear assembly includes a rack gear, an anchor longitudinally adjustable relative to the rack gear, and an insert received within the anchor. The anchor is coupled with the at least one elongate member such that adjustment of the anchor relative to the rack gear longitudinally moves the insert and the at least one elongate member for adjusting tension of the at least one elongate member.