The New ARB Air Locker

The Chrysler 8 ¼ axle has been around many years, and is most recently fitted into the rear of Dodge Dakotas and Jeep Cherokees. While a fairly substantial diff, and a lot better than the 35C found in earlier rigs, it is a small, C-clip design axle, which makes fitting traction diffs into it a bit difficult. We advocate axle upgrades all the time, but we can’t all afford a custom Dana 60. Many of us want to be able to upgrade what we already have, and that factory Trac-Lok just doesn’t cut it on the tough trails. You could simply get an Auburn limited slip, a Detroit Locker, or even a Powertrax unit, but the folks at ARB wouldn’t supply an Air locker—that is—until now. One of the reasons for this is that the smaller a differential, the more critical the design needs to be for maximum strength and performance. That’s why ARB has recently released its second-generation Air Locker, which makes a good thing even better.

With a bulletproof two-piece carrier and timed spider gears, the new unit is also easier to install with fewer problems with air leakage. This new design eliminates the long through-bolts holding the three-piece unit together, and moves the air inlet from the right-side carrier bearing to the bearing assembly near the ring gear flange. This greatly increases the rigidity and strength of the case itself, while eliminating the need to modify the bearing caps by notching or drilling. Most important, new timed gear technology ensures that all four spider gears are more positively engaged with the side gears so that torque loads are evenly distributed within the unit.

Since we needed bigger rubber for more clearance (and the accompanying lift), we opted for this new ARB as a one-finger wonder in the engagement department, and trundled off to Drivetrain Direct for an install. At the same time we popped in some 4.56 gears (the lowest available) so our new Cherokee can handle the bigger meats. With the new ARB seal design on the air inlet, installation is much easier and quicker, which saves time and money in the labor department. Check out how we upgraded what we have, rather than dropping tons of cash on custom axles.