Yukon Gear & Axle YDAF9-370-31 Dropout Assembly for Ford 9" Differential, 31 Spline, 3.70 Ratio

The Yukon Gear & Axle YDAF9-370-31 is a complete, ready-to-install dropout assembly (third member) designed for the iconic Ford 9-inch differential. Built by expert Yukon technicians, this assembly arrives fully shimmed and backlashed to factory specification — eliminating the time-consuming and error-prone setup work typically required when rebuilding a differential.

Key Features:

• Axle Spline Count: 31 spline
• Gear Ratio: 3.70
• Application: Ford 9" differential housing
• Carrier Type: Open differential (non-locking)
• Case Material: Nodular iron for improved rigidity and power handling
• Assembly: Complete, fully shimmed and backlashed to spec
• Yoke: Not included — must be sourced separately

Installation is straightforward: simply drop the third member into your existing Ford 9-inch differential housing, bolt on the differential cover, fill with gear oil, and you're ready to go. The nodular iron case construction reduces deflection under load, ensuring consistent gear contact and long service life. This is an open differential unit — ideal for street and general performance builds where a 3.70 gear ratio is desired.

Note: Pinion yoke is not included with this assembly.