Chromoly Rear For Dana 44 Narrow Track W/Elocker Left Hand 31.56 Long D44 JL Rubicon 31.56 Inch Left Hand Small Bearing SET10 (Opt. Dre) 32 Spline 4340 Rear Double Drilled Yukon Gear & AxleYukon performance axles are built with high tensile strength 4340 chromoly, use superior production methods that include cold roll formed splines, and feature advanced 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