Chromoly Inner Front For Dana 44 Diff 32 Spline Left Hand 21.3 Long D44 JL & Jt Rubicon 32 Spline Left Hand Inner 21.3 Inch 4340 1350 Series 7166 Joint M210 Wide Track Front Yukon Gear & AxleYukon high performance axles are built with high strength 4340 chromoly, use superior production methods that include cold roll formed splines, and feature induction coil heat treating to create an axle of unmatched quality and durability. Yukon high performance axles are built with high tensile strength 4340 chromoly, use superior production methods that include cold roll formed splines, and feature advanced induction coil heat treating to create an