Yukon front 4340 Chrome-Moly replacement axle kit for Dana 30 Jeep XJ, YJ and TJ with 30 spline axles Yukon 4340 Chrome-Moly axles provide up to 50% increased strength over stock axles for use in extreme performance applications with large tires and high horsepower Yukon's 4340 axles are manufactured using the latest technologies and the highest quality materials to ensure high strength and long life This kit comes with inner and outer axles for both left and right sides along with Dana u-joints Limited Lifetime warranty covers manufacturing defects and axle breakage for as long as you own the vehicle