When the Ford 9-inch axle originally appeared in 1957 under the Fairlane and F-100 pickup truck, no one knew what an enduring legacy it would have. To put that in perspective, the top-of-the-line Fairlane used four-wheel drum brakes and manual steering, and made 245 hp from the carbureted FE engine. You wouldn’t swap any of those parts under your 4x4 today, but the 9-inch still enjoys incredible popularity. In fact, despite being discontinued by Ford in 1986 in favor of the 8.8 axle, there are more 9-inch parts on the market now than ever before.
We spoke to Brian Shephard, marketing director at Currie Enterprises, to get the lowdown on what makes the 9-inch so popular. While Currie offers everything from 12 Bolt to Dana 70 axles for 4x4s and hot rods, the 9-inch has been the company’s bread and butter for decades. In fact, these days, you can only order up a 9-inch from Currie that is built entirely from new parts. Conversely, you can pull a Ford 9-inch out of a truck in a junkyard and swap it under your rig for a couple hundred dollars. Most people mix and match new and used parts to get the most bang for the buck.
There are several reasons the 9-inch enjoys such a strong following. The removable third member makes gear changes much easier than Salisbury-style (Dana) axles. The use of a removable pinion support and spanners instead of carrier shims makes gear setup easy. And there are a nearly infinite number of gear ratios available for the 9-inch, from as high as 3.00 and as low as 6.50. The removable third member also means that the sheetmetal housing is not only lighter than a comparable Dana axle but is easier to weld brackets to for your link suspension since you do not have to contend with a cast centersection.
The gear design itself is responsible for the 9-inch’s reputation for holding up to high horsepower. While the ring gear diameter is smaller than a Dana 60, pinion offset from the centerline is 2 1/4 inches for a 9-inch and 1 1/8 inches for a Dana 60. This is a tradeoff, because the Dana 60 will provide a better driveline angle and more ground clearance beneath the yoke, but the Ford 9-inch will have better tooth engagement between the ring gear and pinion due to the angle of the teeth on the 9-inch design. And like a Corporate 14-bolt axle, the 9-inch has a third pinion bearing beyond the pinion teeth that minimizes gear deflection.
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When the Ford 9-inch axle originally appeared in 1957 under the Fairlane and F-100 pickup truck, no one knew what an enduring legacy it would have. To put that in perspective, the top-of-the-line Fairlane used four-wheel drum brakes and manual steering, and made 245 hp from the carbureted FE engine. You wouldn’t swap any of those parts under your 4x4 today, but the 9-inch still enjoys incredible popularity. In fact, despite being discontinued by Ford in 1986 in favor of the 8.8 axle, there are more 9-inch parts on the market now than ever before.
We spoke to Brian Shephard, marketing director at Currie Enterprises, to get the lowdown on what makes the 9-inch so popular. While Currie offers everything from 12 Bolt to Dana 70 axles for 4x4s and hot rods, the 9-inch has been the company’s bread and butter for decades. In fact, these days, you can only order up a 9-inch from Currie that is built entirely from new parts. Conversely, you can pull a Ford 9-inch out of a truck in a junkyard and swap it under your rig for a couple hundred dollars. Most people mix and match new and used parts to get the most bang for the buck.
There are several reasons the 9-inch enjoys such a strong following. The removable third member makes gear changes much easier than Salisbury-style (Dana) axles. The use of a removable pinion support and spanners instead of carrier shims makes gear setup easy. And there are a nearly infinite number of gear ratios available for the 9-inch, from as high as 3.00 and as low as 6.50. The removable third member also means that the sheetmetal housing is not only lighter than a comparable Dana axle but is easier to weld brackets to for your link suspension since you do not have to contend with a cast centersection.
The gear design itself is responsible for the 9-inch’s reputation for holding up to high horsepower. While the ring gear diameter is smaller than a Dana 60, pinion offset from the centerline is 2 1/4 inches for a 9-inch and 1 1/8 inches for a Dana 60. This is a tradeoff, because the Dana 60 will provide a better driveline angle and more ground clearance beneath the yoke, but the Ford 9-inch will have better tooth engagement between the ring gear and pinion due to the angle of the teeth on the 9-inch design. And like a Corporate 14-bolt axle, the 9-inch has a third pinion bearing beyond the pinion teeth that minimizes gear deflection.