Ford 9-inch 31-spline Rear Axle, 78-79 Ford Bronco, 73-79 Ford F150 SKU: 798606NET

Black Forge™ 31-spline Rear Axle for Ford 9" | 78–79 Bronco & 73–79 F-150 

If you’re running bigger tires and putting serious torque through your drivetrain, this Black Forge™ 31-Spline Rear Axle for 1978–79 Ford Bronco and 1973–79 F-150 4x4 is built to take it. Constructed from 1541-H alloy steel with a black oxide finish, this axle is designed to handle the added load and hard use of off-roading and high-traction setups. At 32" overall length, it fits either side and comes fully assembled.

• 1541-H alloy steel construction: Superior strength for high-torque and off-road applications

• 31-spline shaft: Fits right into the factory 31-spline Ford 9-inch rear end for a clean install

• Black oxide finish: Resists corrosion and adds surface hardness for long-term durability

• Tapered roller bearing design: Handles increased side loading from oversized tires and aggressive driving

• Fully assembled: Ready to install out of the box—no pressing or setup required

Additional Info

• Fitment: 1978–79 Ford Bronco; 1973–79 F-150 4x4 (right or left side)

• Overall Length: 32"

• Retainer Hole Size:

  • 1973–1978: 1/2"

  • 1979: 3/8"

• Spline Count: 31-spline (Ford 9-inch)

Built from 1541H alloy with a black oxide finish, this axle delivers serious strength for off-road rigs and high-powered a 78-79 Bronco or 73-79 F150 4WD truck.