The Ford 9-inch is an automobile axle manufactured by Ford Motor Company. It is known as one of the most popular axles in automotive history. It was introduced in 1957 model year cars and ended production in 1986, having been phased out in favor of the Ford 8.8 inch axle. However, aftermarket companies still produce the 9-inch design. It is a semi-floating drop-out axle and had a GAWR up to 3,600 lb (1,630 kg).
One of the features which distinguishes this axle from other high-performance or heavy-duty domestic solid axles is that unlike other axle designs, access to the differential gears is not through the rear center cover; rather, in the Ford 9 inch, the rear cover is welded to the axle housing, and access to internals is obtained 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.[1] Although this requires disconnecting the driveshaft to access the internal gearset, 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.
Note:[note 1]
Ford's 9-inch rear end is so durable it's a wonder Ford stopped making it
