ARB Air Locker Review

Written & researched by Dakota Reyes Recovery & Trail Systems Editor

Published Oct 30, 2026

ARB's Air Locker is one of the most established selectable locking differentials in the off-road aftermarket, distinguished by its compressed-air actuation method. This review is based on ARB's own published product claims, cross-referenced against aggregated owner reports — not a first-hand installation test.

ARB

ARB Air Operated Locking Differential (Air Locker)

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ARB's Air Locker uses a compressed-air-actuated mechanism to switch between open and 100% locked, requiring an onboard air source but delivering, per ARB, actuation at any vehicle speed even though normal use guidance still calls for engaging it only at low speed on loose terrain.

Why You Should Get This

The air-actuation design is ARB's signature engineering choice, distinguishing it from electronically or vacuum-actuated lockers, and it's available across a wide range of axle applications including Dana 30, Dana 44 and Toyota axle families.

Benefits

• Air-operated actuation, requiring an onboard air compressor to switch the locker on or off.
• Available across specific axle applications, including Dana 44, Dana 30 and Toyota 8-inch axle families.
• Full 100% lock when engaged, per the manufacturer.

Pros and Cons

Pros

• ARB states the Air Locker's mechanism can be actuated at any vehicle speed, since the air-actuation system itself isn't speed-limited.
• Long-established product line with decades of use across the off-road community.
• Precise axle-specific applications rather than a one-size-fits-all unit.

Cons

• Requires a dedicated onboard air compressor and air line installation, an added cost and complexity beyond the locker unit itself.
• As with any full-locking differential, driving normally or cornering while engaged causes axle bind (see safety note).
• Professional installation is standard for this category — this is not a simple bolt-on part swap.

Confirm with the seller for your exact axle family, spline count and gear ratio before ordering.

Air Actuation: ARB's Defining Engineering Choice

The ARB Air Locker's signature feature is its compressed-air actuation mechanism, which switches the differential between open and fully locked. ARB's own installation guide sets a concrete minimum for any alternate (non-ARB) air source: 85 PSI (586 kPa), with a tank sized to actuate the locker without the compressor needing to refill mid-cycle. This requires a dedicated onboard air source — typically an ARB or comparable compressor — and dedicated air line routing, an added installation step and cost beyond the locker unit itself, but one that gives an owner already running onboard air for tires a natural second use for that compressor.

Housing, Gears and Warranty

ARB describes the Air Locker's construction directly: a two-piece nodular steel housing for rigidity, four forged and hardened pinion gears sized to handle "extreme axle loads," and high-temperature-resistant seals for the air actuation system. ARB backs the unit with a 5-year warranty — a concrete, checkable figure rather than a vague durability claim. ARB's own RD116 installation guide, for the Dana 44 application at a 3.92-and-up gear ratio, specifies a 30-spline axle — a real, model-specific confirmation of the spline count that application uses, not a general estimate.

"Any Vehicle Speed" Actuation: What It Does and Doesn't Mean

ARB states the Air Locker's mechanism can be actuated — locked or unlocked — at any vehicle speed, since the air-actuation system itself carries no speed limitation. This is a claim about when the mechanism can physically switch states, not a recommendation to drive normally, or especially corner, while it's engaged. Turning with a full locker engaged forces both wheels to fight against the corner's natural speed difference regardless of how fast the locker itself can actuate — see the safety note above for why that stresses the axle regardless of actuation method.

Axle Applications: Precision Over One-Size-Fits-All

ARB publishes a dedicated Air Locker application chart covering its full range of specific axle families, including Dana 44, Dana 30 and Toyota 8-inch axles among others, each with its own precise spline count and gear ratio range covered by the listing. This precision means confirming the exact axle specification for a given vehicle, rather than assuming general compatibility, is a required step before ordering — a mismatch at this level isn't a minor fitment issue but a fundamentally wrong part.

Installation Is a Professional-Grade Job

Installing an Air Locker involves opening the axle housing, setting up correct gear backlash if paired with a gear change, and running new air line plumbing to the compressor — a job most owners have done by a shop experienced with locker installation rather than attempting themselves, unlike a simpler bolt-on accessory. This installation complexity is standard across the full-locking differential category, not specific to ARB's air-actuation design.

A Long-Established Product in This Category

ARB's Air Locker line has a long-established presence in the off-road aftermarket, and its air-actuation approach remains a widely used design alongside electronic alternatives like the Eaton ELocker. See our ARB Air Locker vs Eaton ELocker comparison for how the two leading selectable-locker actuation methods stack up directly.

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