Powertrax 9204302700 No-Slip Traction System (DANA 30, 27 Spline Open) Combines the smooth operation of a limited-slip differential, with the traction performance of a locking differential A precise synchronization mechanism eliminates the ratcheting sounds typical of other locking differentials Special gear and spring design reduce the backlash and therefore driveline windup Only ultra strength material is used which is 67% stronger than titanium Simple installation because no ring and pinion set-up, no special tools or oils, are required; step by step model specific instructions are provided with every kit