Ultimate 88 axle kit 95-02 Explorer, 4340 Chrome-Moly (Double drilled axles). The Yukon Ultimate 88 kit eliminates the factory c-clips and converts your housing to use two 4340 Chrome-Moly bolt in axles. No welding is needed, just a little cutting to remove the factory axle bearing seat. The result is a super strong setup to give you years of hard use on the trail! Yukon 4340 Chrome Moly alloy rear axles come with a limited lifetime warranty against manufacturing defects.