Ford Authority

Iconic Ford 9-Inch Rear End Turns 65 Years Old, Still Going Strong

For some, the age of 65 is a time when we get to retire and start traveling or doing those little projects around the house. But for the iconic Ford 9-inch rear end, there’s no time to rest. In fact, the Ford 9-inch is arguably just as popular as it ever has been, and is still the rear end of choice for hot rodders and drag racers all over the world, whether they own a Blue Oval vehicle or not.

The legendary 9-inch debuted way back in 1956 for the 1957 model year, and both was and is a revelation. The Ford rear end has become a favorite of drag racers over the years thanks to the fact that it is stronger than General Motors’ 12-bolt and lighter than a Dana 60. It’s also quite simple and can be completely assembled and disassembled by anyone with basic tools.

Unlike other rear-end designs, accessing the differential gears is accomplished by removing the center cover on the pinion (front) side of the axle through which the driveshaft yoke connects, with the differential assembly coming out of the axle as a unit attached to the cover, rather than through the rear center cover, as it is welded to the axle housing.

This requires disconnecting the driveshaft to access the internal gear set, but it offers the advantage of being able to disassemble and reassemble the differential gears and adjust clearances conveniently on the benchtop, rather than with the restricted access of working within the axle housing under the car.

Over the years, the 9-inch has seen duty in a host of Blue Oval models including the Ford F-150, Ford Mustang, Ford Bronco, Fairlane, and Thunderbird, to name just a few.

The 9-inch was used in production vehicles through 1986 before it was replaced by the 8.8-inch, but the aftermarket has taken over where Ford left off. Today, we can buy all sorts of parts and entire rear ends from a host of sources, and these companies just continue to perfect what was already a nearly-perfect product.

We’ll have more Ford history to share soon, so be sure and subscribe to Ford Authority for continuous Ford news coverage.

Brett's lost track of all the Fords he's owned over the years and how much he's spent modifying them, but his current money pits include an S550 Mustang and 13th gen F-150.

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  1. Mark L Bedel

    It’s not particularly amazing that good, solid engineering yields this kind of success, but happy 65th birthday all the same 9″. I was fortunate to have one of these in a modified 1960 Falcon, with 3.90 gearing.

  2. John Klawitter

    In a 1966 Ford Custom 2 dr. with the 427, 425 hp side oiler and 4-speed, the rear gear was a 9 3/8″ size versus a 9″. Didn’t discover that until disassembling to install a 9″ Detroit Locker assembly, which of course wouldn’t work!

  3. Jim Ray

    I own a 68 Mustang Fastback GT since 1976 it’s the original 3 1/4 ratio open rear end has 400,000 Mi Plus


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