Dropout Assembly For Ford 9 Differential 31 Spline 4.56 Ratio 9 Inch Ford 4.56 Ratio W/ 31 Spline Std Carrier 3RD Member Assembly (W/O Yoke) Yukon Gear & AxleYukon dropout assemblies are built by expert Yukon technicians and come complete, fully shimmed and backlashed to spec. All you do is install the third member into your diff housing, bolt on the diff cover, add fluid, and roll. Yukon dropout assemblies are built by expert Yukon technicians and come complete, properly shimmed and backlashed to spec. All you do is install the third member into your diff housing, bolt on the diff cover, add fluid, and