Swapping A Junkyard Ford 9-Inch AxlePosted in How To: Transmission Drivetrain on October 1, 2011
There are only few go-to axles that we like to use when doing a budget axle swap. We typically look for these axles because they are strong, easy to find, inexpensive, and easy to modify. The Ford 9-inch is the king of swapped-in axles. No other axle enjoys as many aftermarket parts. Versions of the Ford 9-inch can be found under muscle cars, hot rods, roundy-round race cars, desert prerunner trucks, and of course Jeeps. You could even build a Ford 9-inch completely out of aftermarket parts. But our favorite wrecking yard version of the Ford 9-inch can be found under ’74-’86 F-150s and ’78-’86 Broncos. It features the legendary Ford 9-inch ring and pinion strength, 5-on-5.5 lug pattern (same as older Jeep), a 65-inch width at the wheel mounting surfaces, large-bearing semi-floating axles, and many can be found with hefty 31-spline axleshafts. Another bonus is that the axleshafts are of equal length, so you’ll only need to carry one spare should you choose to.
The V-8, manual tranny with 6.32:1 First-gear, and 37-inch tires proved too much for the Dana 44 rear axle in our somewhat-heavy ’73 J2000. Fortunately our favorite Ford 9-inch is a perfect swap in a Wide-Trac FSJ. We snagged a complete 9-inch from the local wrecking yard for just under $200. We actually ran it as-is in our Jeep with the same gear oil and brakes for several months before regearing it to match the front axle. But first it needed some modifications to get it under the back end of our J-truck.