Ford 9 Inch Differential Information

The Ford 9″ axle is a semi-floating, drop-out with a GAWR up to 3600 lbs and is one of the most popular axles in automotive history. Ford began production in 1957 and stopped production in 1986 though many after market companies still produce this rear end.


The Ford 9″ has a stamped housing with axletubes welded on each end and nothing else. This makes the rearend easier to service because of its removable centersection that houses the gearset. This removable gear case houses a differential unit that the ring gear bolts onto. What sets the Fo
rd 9″ apart from other high performance and heavy duty solid axles is that access to the differential gears is not through the rear center cover, which is welded to the axle housing, but through the center cover on the pinion side of the axle where the drive shaft connects.

Ford 9″ Benefits

The Ford 9″ has a number of benefits over its competition, here are just a few of them.
In a Ford 9″ swapping gears is supremely easy as it has a removable third member. This is even more important if for dual purpose vehicles.

A Ford 9″ also makes axles easy to install or remove as Ford designed the axle to slide out by yanking four bolts per axle flange for the 28- and 31-spline axles.

An added plus for the Ford 9″ is an internal rear-pinion support that also supports the gear end of the pinion to limit gear deflection under high torque loads.

Ford improved tooth contact in the Ford 9″ by locating its pinion gear lower on the ring gear. This strengthens the rear end assembly but results in a minor loss of power to drive the gears.

A Ford 9″ can save you money if the worst should happen. At some point no matter what axle you buy, that axle will break if you are doing something rough. With a Ford 9″ if the axle breaks inside the housing, the axle retainer keeps the axle in place, where in other types the axle would slide out potentially causing massive sheet metal damage.

The Ford 9″ also has the widest variety of ratios on the market, so no matter what you have chances are excellent a Ford 9″ can work with it. Check out some of the parts we have to go with your Ford 9″ 28 spline, 31 spline, or 35 spline.

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