A VAFN system is provided for a fan case of an engine. The system includes a motor; a gearbox; an actuator; a nozzle; and a drive coupling extending between the gearbox and the actuator and configured to transmit the mechanical torque from the motor to the actuator. The drive coupling includes an external tube extending from a first one of the gearbox or the actuator, the external tube defining first and second slots extending in a longitudinal direction, and an internal tube extending from a second one of the gearbox or the actuator and at least partially extending within the external tube, the internal tube including a pin with first and second ends respectively positioned within the first and second slots such that the internal tube is configured to translate within the external tube and to be rotatably coupled to the external tube.