A 4x4 air locker is a type of differential locking system used in four-wheel-drive (4x4) vehicles that uses compressed air to provide on-demand, full axle locking for increased traction in challenging off-road conditions. Essentially, it allows you to force both wheels on an axle to spin at the same speed, regardless of available traction.
How Air Lockers Work
Here's a breakdown of how an air locker functions:
- Normal Differential Action: Under normal driving conditions on paved roads, the differential allows each wheel on an axle to spin at different speeds, which is necessary for turning corners.
- Traction Loss: In off-road situations, one wheel may lose traction (e.g., be lifted off the ground or spinning on ice). With a standard or limited-slip differential, power will be directed to the wheel with the least resistance, causing it to spin freely while the other wheel receives little or no power.
- Air Locker Engagement: When an air locker is engaged, compressed air actuates a mechanism within the differential, effectively locking the two axle shafts together.
- Full Axle Lock: With the axle locked, both wheels are forced to spin at the same speed, regardless of traction. This ensures that even if one wheel is spinning freely, the other wheel will receive full power, potentially allowing the vehicle to drive out of a difficult situation.
- Disengagement: When the air locker is disengaged, the differential returns to its normal open configuration, allowing for safe and predictable handling on paved roads.
Benefits of Air Lockers
- Maximum Traction: Provides maximum possible traction when engaged.
- On-Demand Locking: Can be engaged and disengaged as needed, preserving on-road drivability.
- Improved Off-Road Performance: Significantly enhances a 4x4's ability to navigate challenging terrain, such as rocks, mud, and snow.
- Durability: Typically built with robust materials to withstand the stresses of off-road use.
Considerations
- Installation: Requires professional installation, often including running air lines and mounting an air compressor.
- Cost: Air lockers are more expensive than other types of locking differentials.
- On-Road Use: Should only be engaged in low-traction situations; using a locked differential on paved roads can cause damage to the drivetrain and affect handling.
- Maintenance: Requires occasional maintenance, such as checking air lines and compressor.
Example
Imagine your 4x4 is climbing a rocky trail. One of your rear wheels loses contact with the ground and starts to spin. With an open differential, all the power goes to that spinning wheel. However, if you engage the air locker in the rear axle, both rear wheels are forced to turn together. The wheel still on the ground now receives power and helps propel your vehicle forward.
