Yukon Gear & Axle (YA WU-07) Spin Free Locking Hub Conversion Kit for Jeep TJ/XJ/YJ Dana 30 Differential 1 Year Warranty Spin Free Kit replaces the vulnerable and expensive factory unit bearings with tapered bearings and races Significant increases in mileage per gallon Includes new wheel hubs, spindles, high strength Yukon 4340 Chrome-Moly outer axles, premium locking hubs, Timken bearings, high quality seals and all hardware for installation. 5 x 4.5" bolt pattern