Ford 9-inch Differentials & Lockers

Early Bronco Ford 9-inch Rear Differential & Locker Options

There are many different types of differentials on the market for the Ford 9-inch rear axle. The early Bronco came from the factory with either an open or a limited slip (posi) type differential. The open differential transmits the power through just one axle. This leaves a lot to be desired in off-road situations.

The factory early Bronco limited slip units are more desirable. They use internal clutch packs to transmit power to both axles. When you go around a corner these clutch packs allow slip so the outside wheel can turn faster. This "slip" can be the thing that causes frustration off-road because these units can slip right at the point where you need power at both wheels. A driver with finesse can get a lot out of a limited slip unit and they are quiet and for the most part trouble free.

That brings us to locking differentials. For the best off-road performance a locking differential is the answer for your early Bronco. The legendary Detroit Locker has been proven over the test of time. The Detroit Locker or the Yukon Grizzly Locker is the choice of many hard core wheelers because of their simplicity. Install it and forget about it. These are fully automatic locking differentials and are completely maintenance free.

Finally, we get to selectable lockers such as the incomparable ARB air locker. The beauty of these is the ability of the driver to turn them on and off with the flip of a switch. This is the choice of many off-roaders who also drive a lot on the street. These differentials are fully open when not switch on, resulting in quiet, smooth operation on the road with no adverse affects on tires or handling. When you get to the rough stuff just hit the switch and now you have a fully locked differential. The ARB air locker has been around since the early 90's. They have been tested at about every hard-core wheeling spot on earth and have proven their performance and reliability. So how does it work? Hit the switch and in one tenth of a second compressed air actuates a piston inside the differential which engages a locking gear, instantly locking the differential and directing torque to both driving wheels. Once you get through the hard spot, just hit the switch and the differential lock is disengaged.