More like a complete kit, our Four-Wheel Drive (4WD) Actuator comes with all the parts to complete the repair. Since this part is a direct replacement, the exact fit adds efficiency and convenience. When it comes time to replace your worn-out or failed 4WD differential actuator, look no further than Dorman. These replacement front axle actuators are available in the original vacuum or electric-style, just like OEM. Trust Dorman for the trouble-free engagement of your 4WD system.