Whether in lightweight buggies, high-speed desert trucks, or big-power muscle cars, the Ford 9-inch axle is a proven contender, and the Currie name has been synonymous with this dropout-style axle for 50 years. The original stamped steel housings have long been eliminated from the Ford factory offerings, but the simple and strong removable-carrier housing axles (also known as banjo style) are still being made by Currie.
One of the latest upgrades Currie has offered is its fully fabricated F9 axlehousings. Unlike the old-style housings, these fabricated housings offer greater ground clearance even with the pinion rotated up to 20 degrees, a stronger structural design, and multiple axletube diameter and thickness options. These trick axleshousings can also be ordered ready to bolt into a Jeep TJ or JK Wrangler as an awesome instant axle upgrade.
We recently had the chance to follow the assembly of an F9 housing as well preview some even bigger, badder axle options coming from Currie.
Indy-Axle
We mentioned the prototype F9 Heavy Duty fabricated housing, which is larger and allows for up to a 4-inch axletube, but here is another interesting offering from Currie, the F9 Independent. This all-steel third member is just what you need for your custom four-wheel-drive independent suspension. We imagine you'll see some homebuilt long-travel IFS rockcrawlers and desert runners in the future, and this should make it that much easier.
Currie offers many different...
Currie offers many different 9-inch centersections, including its narrow body standard hot rod 9-inch (lower left); the Centurian, a stronger version of the company's 9+ housing (upper left); the F9 (lower right); and the soon-to-be-released F9 Heavy Duty (upper right). Currie sources many of its parts in America and recently began bringing business back from overseas for quality made in the USA.
The F9 housing starts as a...
The F9 housing starts as a housing made of a 3/16-inch steel body and a 3/8-inch steel mounting surface for the third member. The steel, known as Hi-Form 50, is high-strength steel that lends itself to bending and forming cleanly without breaking or cracking. The axletubes are 3- or 3 1/4-inch-diameter, 1/4-inch wall and have the ends machined to lock into place in the housing.
Alignment of the axle is crucial,...
Alignment of the axle is crucial, and a center bar with large bearing pucks is used to align the housing with a third member installed. The widths are double-checked for accuracy with the customer's order and then tack welds are burned in to hold the axlehousing assembly.
The housing then goes to the...
The housing then goes to the welding department, where the tubes are burned into place. The design of the housing results in the tubes being welded inside, outside, and along a bulkhead face for additional strength. All the welds are pressure-tested prior to shipping to guarantee against leaks.
Since the heat from heavy...
Since the heat from heavy welding can pull the housing out of alignment as it cools, the housing is sent to be aligned in a giant press. More trussing can be added for unbendable strength depending on the customer's order.
The fabricated F9 housings...
The fabricated F9 housings are great for attaching suspension brackets since they can be welded anywhere on the housing. Currie has housings engineered to work with most Jeep Wrangler TJ and JK suspension systems that use the factory Jeep axle mounts. This means you can unbolt your lightweight Jeep axles and bolt in a stronger yet still lightweight set of Currie F9s. Currie will also build custom widths and offsets as ordered.