WH Custom Built Ford 9-inch Third Member, 31 Spline SKU: 8599NET

Custom Built Ford 9-Inch Third Member | 31-Spline

When you’re building serious power, your drivetrain needs to keep up. Our Custom-Built Ford 9-Inch Third Members are built-to-order, using premium all-new components — no used cores, no compromises. Starting with a Yukon extra heavy-duty nodular iron dropout housing and a solid spacer bearing kit, this third member is engineered for strength and reliability, ready to handle the demands of high-torque applications.

We let you dial in your perfect setup by choosing your desired gear ratio and differential option. Whether you’re looking for street manners with traction control or full-on off-road traction with a locker, we’ve got the right configuration for your build.

Want it turnkey? Select our assembly option, and we’ll build your third member in-house so it’s ready to bolt right in. Just add oil and hit the road (or trail)!

• Built to Order:
  Customize your third member with your choice of gear ratio and differential.

• Zero Core Charge:
  100% brand new components — no used or rebuilt parts.

• Heavy-Duty Yukon Dropout:
  Extra heavy-duty nodular iron case for maximum strength.

• Solid Spacer Bearing Kit:
  Superior bearing preload control for durability under load.

• 31-Spline Strength:
  Handles big power and torque for serious off-road and street builds.

• Turnkey Option:
  Select assembly and we’ll build it for you — bolt in, add oil, and go!

• Available Gear Ratios:
  3.50, 4.11, 4.56, 4.88, 5.13

• Locker Options:
  Grizzly Locker, Eaton Truetrac, or ARB Air Locker for your performance needs.

Built to handle big power! Custom 9" third member, 31-spline, all-new parts, your choice of gears & locker. Bolt it in, add oil, and hit the trail!