Locking Hub Conversion Kit for Jeep XJYJ & TJ Dana 30 front5 x 5.5 bolt pattern. The Yukon worry free Spin Free Kit replaces the vulnerable and expensive factory unit bearings with tapered bearings and races. The result is not only a design which is easier and more economical to servicebut one that offers significant increases in mileage per gallon. This hub kit also includes low-profile Yukon Hardcore premium locking hubsgiving you more driving selectability. This kit includes new wheel hubsspindleshigh strength Yukon 4340 Chrome-Moly outer axlesYukon Hardcore premium locking hubsTimken bearingshigh quality seals and all hardware for installation.