THE REQUIREMENT
A common misconception suggests that a 4x4 and traction go hand in hand… you can’t have one without the other. The truth, however, is that most 4x4 vehicles send power to the wheels with the least amount of traction once difficult terrain is encountered. The problem is simple – when one (or more) of your vehicle’s wheels loses traction, your highway minded factory differential directs all of your vehicle’s power to those spinning wheels. On road, the standard "open" differential allows each of your wheels to turn independently thus eliminating any binding during turns. Off road, this becomes a major burden as engine power will take the path of least resistance, which occurs at the wheels with little or no traction.

Newer vehicles with limited slip differentials (LSDs), positraction etc may offer some improvement over standard differentials, but more often you’ll find the slipping is not "limited" enough to maintain forward progress. Automatic locking differentials also have their disadvantages. Aside from being noisy, automatic locking differentials often upset the on highway and off road driving characteristics of your 4x4. During normal driving conditions, vehicle responsiveness becomes less predictable, and when highway surfaces become wet or icy, the driver must use extreme caution just to keep the truck in control.

THE SOLUTION
ARB has been challenging conventional thinking on off road equipment designs for over 30 years, and the ARB Air Locker has been a success from the very beginning. Created to provide 100% traction on demand, without sacrificing any of your vehicle’s highway driving performance, ARB Air Lockers employ a 12 volt air compressor designed to activate (and deactivate) a solid and durable locking mechanism inside the differential. This gives you the traction you need, when you need it, all at the flick of a switch, all within the safety and comfort of the driver’s seat.

The advantage of the ARB Air Locker lies in the pneumatically operated locking system inside the differential. When activated, the Air Locker prevents the differential gears from rotating and therefore prevents the axle shafts from turning independently of each other. With both wheels tied directly to the rotation of the ring gear the vehicle maintains maximum possible traction at all times. When unlocked, it operates just like conventional "open" differentials.

In addition to providing outright improvements to a 4x4’s off road capabilities, the Air Locker offers significant environmental benefits. When approaching difficult terrain, less reliance is put on momentum. An Air Locker equipped truck can be driven in a slower, safer and more controlled manner as a result of vastly improved traction. This style of driving greatly reduces the likelihood of incurring vehicle damage and lessens the environmental impact as well.

AVAILABILITY & INSTALLATION
Air Lockers are currently available in over 100 configurations to suit a wide range of 4x4 vehicles from around the world. Because the Air Locker is only engaged when needed, it can be installed in BOTH the front and rear axles, with separate switches independently controlling the locker from within the truck.

Installation should be performed by a qualified differential technician, although no special tools or skills are required apart from those necessary for fitting a standard differential. When installed with an ARB air compressor, the locker system is supplied as a complete kit which contains all of the parts necessary for proper installation, including industrial grade control switches, air lines and fittings. ARB offers two compressor models suitable for Air Locker operation. A dedicated air activation system is available which is extremely durable and compact. Alternatively a larger compressor can be specified, which is also perfect for inflating tires, air mattresses and a host of other applications where compressed air is required.

1999 and newer axle shafts may need .005" dia. removed for proper fit. Front/Rear Year:1983 on AMC Model 20, 8.875" dia. DescriptionRG 31.8 (1.25") Shaft Spline29 Ratio 2.73