Selectable Diff Locker vs Auto Locker: Choosing the Best Differential Locker

Estimated reading time: 7 minutes

Key Takeaways

• The choice between a selectable diff locker vs auto locker is crucial for optimizing off-road performance.



• Selectable lockers offer manual control, while auto lockers engage automatically when traction is lost.



• Consider factors like driving habits, vehicle use, cost, and maintenance when choosing a locker.



• Air lockers and E lockers are types of selectable lockers with unique activation methods.



• Understanding the advantages and disadvantages of each locker type ensures the best fit for your 4WD needs.

Differential lockers are essential for 4WD enthusiasts seeking maximum traction in challenging off-road conditions. These devices are crucial for maximizing traction in tough off-road environments, allowing 4WD vehicles to conquer obstacles that might otherwise be impassable. Choosing the right locker can make the difference between conquering tough terrain and getting stuck. Selecting the appropriate locker can mean the difference between a successful off-road adventure and getting stranded. One of the most common discussions among off-road enthusiasts is the choice between selectable diff locker vs auto locker. This guide will explore various types of differential lockers, including their operation, benefits, drawbacks, installation costs, and suitability for daily driving.

Understanding Differential Lockers

What is a Differential Locker?

A differential locker is a device that locks the differential, ensuring both wheels on an axle rotate at the same speed, regardless of traction conditions. This setup is invaluable during off-road scenarios where one wheel may lose traction, enabling power to be evenly distributed to both wheels, improving the vehicle’s ability to move forward. Camera Source

In standard operation, a differential allows wheels to turn at different speeds, which is necessary for smooth turning on high-traction surfaces. 4 Wheel Parts 4×4 Community Forum

Types of Differential Lockers

• Open Differential: Standard on most vehicles, allows wheels to rotate at different speeds.



• Limited Slip Differential (LSD): Automatically biases torque toward the wheel with more traction.



• Automatic (Auto) Locker: Locks automatically when a traction difference is detected.



• Selectable Locker: Can be manually engaged or disengaged by the driver.



• Air Locker: A type of selectable locker actuated by compressed air.



• E Locker: An electronically activated selectable locker using an electric solenoid.

Selectable Differential Lockers vs Auto Lockers

Selectable Differential Lockers

Selectable lockers provide the driver with full control, acting as an open differential until manually locked. Selectable lockers remain open during normal driving and can be locked on-demand by the driver for maximum traction. OVR Magazine

Advantages:

• Full driver control over engagement.



• Maintains normal handling characteristics on pavement.



• Reduces unnecessary wear and drivetrain stress compared to always-on lockers.

Disadvantages:

• Higher cost due to complexity.



• Requires additional components (e.g., air compressor, wiring) for activation.



• More complex system may lead to increased maintenance requirements.

Auto Lockers

Auto lockers automatically engage when a traction difference is detected, without driver intervention. They sense when one wheel loses traction and automatically lock the differential to distribute power evenly.

Advantages:

• Simplicity of operation—no need for driver input.



• Generally robust with fewer components to fail.



• Typically less expensive than selectable lockers.

Disadvantages:

• Can affect on-road driving manners, causing noise and less smooth cornering.



• Less control for the driver over when the locker engages.



• May increase wear on tires and drivetrain components during regular driving.

Comparison: Selectable Diff Locker vs Auto Locker

Feature	Selectable Locker	Auto Locker
Driver Control	Full manual control	Automatic engagement
On-road Comfort	Maintains normal driving feel	Can cause noise and affect smoothness during turns
Off-road Performance	Excellent traction, engages when needed	Excellent traction, automatic engagement
Cost	Higher initial cost and installation expenses	More budget-friendly
Maintenance	More complex, potentially higher maintenance	Simpler, generally low maintenance

Scenarios:

• Selectable Locker Preferred When: The vehicle is used both on-road and off-road, driver desires full control over locker engagement, minimizing on-road noise and wear is important.



• Auto Locker Preferred When: The vehicle is primarily used off-road, simplicity and cost savings are priorities, driver prefers automatic operation.

Air Locker Advantages for 4WD

What Are Air Lockers?

Air lockers are a type of selectable locker that uses compressed air to engage or disengage the differential lock. Air lockers utilize compressed air to actuate the locking mechanism, offering precise control over differential engagement. OVR Magazine

Advantages:

• Precision Engagement: Locking can be activated exactly when needed.



• Strong and Reliable Locking Action: Robust design ensures performance under extreme conditions.



• Eliminates Binding during Turns: When disengaged, preventing bind and tire wear.

Applications:

• Ideal for extreme off-road environments.



• Preferred by serious off-road enthusiasts and professionals.

E Locker Installation Cost

What Are E Lockers?

E lockers are electronically activated selectable lockers that engage via an interior switch. They engage the differential lock using an electric solenoid, controlled by a switch inside the cabin. Unlike air lockers, they don’t require compressors, simplifying installation.

Cost Breakdown:

• E Locker Unit: Ranges from $800 to $1,500.



• Installation Costs: Professional installation may cost $400 to $800.



• Total Installation Cost: $1,200 to $2,300.

Comparison:

• E Locker vs Air Locker: Air lockers often have higher costs due to compressors and complex installation.



• E Locker vs Auto Locker: Auto lockers are cheaper in both unit price and installation.

Mechanical Locker Noise Issues

Noise Issues with Mechanical Lockers

Mechanical (auto) lockers can produce noticeable noises during regular driving, such as clicking, clunking, or banging sounds when mechanical lockers engage or disengage.

Causes:

• Noises result from gear-based mechanisms locking and unlocking.

Solutions:

• Proper Installation: Professional installation can minimize excessive backlash.



• Regular Maintenance: Use manufacturer-recommended lubricants.



• Driving Habits: Smooth accelerations and turns.

Expert Tips:

• Some users report noise decreases as the locker components wear in over time.



• Accepting a level of noise as normal.

Best Locker for Daily Driver

Criteria for Daily Driving

• On-road Comfort: Minimal noise, smooth driving dynamics.



• Reliability: Proven durability.



• Cost-effectiveness: Balance performance benefits with expense.



• Ease of Use: Simple operation.

Comparison:

Locker Type	Comfort	Performance	Reliability	Cost	Best For
Auto Locker	Low	High	High	Low	Dedicated off-road
Selectable Locker	High	High	High	High	Daily & tough off-roading
E Locker	High	High	High	Med-High	Daily driving with occasional off-road
Air Locker	High	Highest	High	High	Hardcore off-roading
LSD	Med	Med	High	Med	Mild off-roading, snowy roads

Recommendation:

E Locker or Selectable Locker: Offers the best balance for drivers who use their 4WD vehicle daily but need strong off-road capability. These options maintain on-road comfort and provide maximum traction when needed.

Conclusion

Choosing between a selectable diff locker vs auto locker depends on specific needs, driving habits, and budget. While selectable lockers offer control and comfort for daily drivers, auto lockers provide simplicity for dedicated off-road use. Air lockers are favored for extreme off-road control, and E lockers balance performance with convenience.

Evaluate typical use — daily driving vs. dedicated off-roading — to determine the best locker for your 4WD.

Additional Resources

• OVR Magazine – Understanding 4WD Lockers



• Camera Source – Locking Rear Differential vs 4×4



• 4 Wheel Parts – What is a Locker and Why Do You Need One

For expert advice tailored to your vehicle and driving needs, contact your local 4WD specialist or trusted mechanic.