Powertrax Lock Right Positive Locking Differentials are a revolutionary design that replaces differential spider gears with a coupler gear set that dramatically increases traction. With spider gear differentials, the wheel that has the least amount of traction typically gets full power, which isn't good for a stuck truck. Lock Right Differentials send power to the wheel that has the most traction, enabling escape from almost any situation. Installation time is about an hour; no special tools or setup required because the ring and pinion gears are unaffected. Note: Installs in open carriers only.