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20th October, 2020

Bring Your A-Game



There is no true 4WD without a locking differential. An Air Locker is needed to make effective use of all the traction available between the tires and the surface of which we are driving on. Air Lockers give you the ability to take advantage of the traction that is available by supplying drive to all wheels when needed but also by providing the flexibility of remaining open when not.


An ARB Air Locker can be engaged at any speed as long as both wheels are spinning at the same rate and your foot is off of the accelerator. Simply engage the compressor switch, then press the Air Locker switch. If one wheel is spinning faster than the other, “crash locking” will occur which can cause damage or premature wear to the internal gears. Best practice would be to ease off the throttle, then engage the Air Locker before attempting the obstacle.

When disengaging your Air Locker, always remember that the teeth of the locking mechanism cannot disengage while under torque. Even with the switch disengaged, you may need to release the torque on your axle by rolling your vehicle forward or backward slightly before the locking mechanism will unlock.


Air Lockers have no special requirements for lubricants; however, ARB does not suggest the use of oil that contains limited-slip additives as they can shorten the life of the Air Locker seals. Oil should be chosen based on the climate that you live in and the nature of how you use your vehicle.

After the first 1,500 miles of use, ARB recommends changing the differential oil and cleaning the axle breather. The Air Locker is larger in mass when compared to the factory differential, thus the fluid capacity of the axle will be different. Fill the axle with oil until the level is at the fill plug hole, manually rotate the differential several times, and then fill again until level with the filler plug hole. Overtime, the axle will naturally find its maximum capacity. After 30,000 miles of off-road use or 45,000 miles of highway only use replace the differential fluid.

* Please view the Air Locker Operating and Service Manual for more information regarding viscosity, intervals, and other oil specifications.


Air Lockers will engage at around 70 PSI. For faster engagement, ARB recommends air pressure between 100 and 150 PSI. Each ARB Air Compressor will provide enough air pressure to engage two Air Lockers. Both the compact CKSA and high-output CKMA compressors will provide 100 PSI. The Maximum Output CKMTA will provide 150 PSI. The pressure switch supplied with the CKMTA, #180901, can also be utilized on the CKSA and CKMA compressors for faster engagement.




A billet-machined, alloy steel spider block supports the cross shafts, using the torque applied at each shaft to support the next shaft along.


Custom made, one-piece hardened retaining pins lock into the assembly using a tapered thread junction.


ARB's patented locking system actually supports the side gear teeth, giving you more torque handling capability, exactly when you need it.


Steel reinforced, elastomer-bonded annular seal has been proven to handle 20,000+ cycles under the most extreme climatic temperatures on earth.


Machining a case from two-pieces instead of three results in a much higher dimensional accuracy of the finished assembly and has allowed ARB Engineers to improve the design of other elements, resulting in a reduction of moving parts, increased strength and a more responsive activation.


Combining the strength of forged nickel alloy steel with redefined gear-tooth geometry, ARB has revolutionized locking differential gear design to yield structural advantages of up to 30% over commercially available high strength gears.


A billet-machined, alloy steel spider block supports the cross shafts, using the torque applied at each shaft to support the next shaft along.


With phenomenal forces being applied to the side and pinion gears within the differential, ARB has invested heavily in the application of forged gears, typically found in heavy-duty commercial, race and agricultural transmissions.


High-grade surface treatments, forged nickel alloy steel and ARB's patented timed locking system make this the most ‘lockable’ gear in the industry.


Alloy steels and performance surface technology make for a high-pressure running fit that can handle an enormous amount of punishment.


Instead of a complex external actuator system to engage/disengage the lock, ARB Air Lockers® use up to 12 return springs to support the entire profile of the locking gear for a fast, positive and independent disengagement.


Fully machined, one-piece nodular iron diff carrier case offers the rigidy of a one-piece factory differential with twice the standard number of pinion gears to cope with the torque.


At the flick of a dash-mounted switch, compressed air is delivered to the seal housing assembly via a nylon air line.


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