Aussie Locker XD-13027 for Dana 30 7.2-Inch 27 Axle Spline Locker The Aussie Locker XD-13027 is the most advanced traction added Automatic Precision Locker in the world today You get 100 percent traction performance rather than 40-60 percent with a posi or LSD All Aussie Lockers are designed for installation in an open differential The Aussie Locker will not work in posi or limited slip carriers The XD13027 is not designed to fit the D30a differential