As nice as it’s been to have a self-contained, automatic-locking differential in the rear of our ’04 4Runner, there were compromises that came with the territory. Some didn’t seem that bad, such as the occasional popping or banging noise as the locker locked and unlocked. You get used to it. Handling changed as the automatic locker engaged under acceleration and disengaged under deceleration. Again, you get used to it. One thing that got old too fast was the accelerated tire wear. Every time a corner was rounded with a foot on the gas (which was more often than not), the rear tires were scrubbing all the way around the turn. And it’s no secret that off-road tires aren’t cheap.
For a dedicated off-road rig, accelerated tire wear with an automatic locker is basically a non-issue. If the rig only gets driven on the weekends and the pavement miles are directly to and from the trail, tires tend to last a long time. On the other hand, tires fade faster with an automatic locker if it’s a daily driver.
Enter the ARB Air Locker. This Australian-made selectable-locking differential has long been regarded as the no-compromise solution for dual-duty driving. Unlocked, it’s an open differential: pavement-friendly and completely compatible with virtually all ABS and traction control systems. When the Air Locker is engaged, it’s completely locked up just like a spool. A locked ARB Air Locker turns both tires in unison, no matter what.
Of course, everything’s a compromise in some way or another. Unlike the automatic-locking differential we’ve been using, the ARB Air Locker isn’t self-contained. Since the Air Locker is air-actuated and selectable, an air source and a switch are both required. Fortunately, ARB offers a complete line of air compressors, wiring harnesses, switches, solenoids, and technical support to make an Air Locker installation successful.
If your off-road rig doubles as a daily driver, the ARB Air Locker is the total solution for your dual-duty vehicle. It’s transparent traction.
02. ARB offers several compressors in its lineup, including a basic model that’s meant solely for powering Air Lockers. The CKMA12 air compressor shown here is an upgraded model that’s capable of not only powering Air Lockers, but also inflating tires with an optional Pump-Up Kit (not shown). A wiring harness, switch, mounting bracket, installation manual, and fastening hardware complete the package.
03. The previously chosen 4.56 gear ratio in our Ford 9-Inch worked great when the 4Runn
04. Odds are you’ll need some new parts when a new ring-and-pinion set is installed. Rath
05. We opted for a completely new third member, including a nodular iron gearcase from Cu
06. Currie Enterprises technician Nicolas Serrato expertly installed the Air Locker and Y
07.0 The Air Locker’s copper actuating line has to be carefully routed around the ring ge
07.5 Nicolas secured the copper line to the differential case with safety wire and a care