A manufacturing assembly is disclosed for manufacturing a disk drive. The manufacturing assembly comprises a pre-merge arm having a contact surface for contacting an actuator arm of the disk drive, and an actuator operable to actuate the pre-merge arm. When installing the actuator arm into the base of the disk drive, the actuator is operable to actuate the pre-merge arm in a first direction so that the contact surface biases the actuator arm rotationally about a pivot to bias the lift tab away from the ramp. After installing the actuator arm into the base of the disk drive, the actuator is operable to actuate the pre-merge arm in a second direction opposite the first direction so that the lift tab moves towards and contacts a ramp near an outer periphery of a disk.