Automatic lockers are one of the most effective traction upgrades available, automatically delivering power to both axle shafts when traction is needed without the complexity of air or electronic locker systems. Unlike an open differential that sends power to the wheel with the least resistance, automatic locking differentials help maintain forward momentum through rocks, mud, loose terrain, steep climbs, and other demanding off-road conditions. Popular in rock crawlers, rock bouncers, Ultra4 race cars, trail rigs, mud trucks, overland vehicles, and heavy-duty trucks, Yukon Grizzly Lockers feature forged cases, large internal locking teeth, and heavy-duty internals engineered to withstand oversized tires, low-range gearing, and high-horsepower applications. Available for axle platforms including Dana 30, Dana 44, Dana 60, GM 14-Bolt, GM 8.5", Chrysler 11.5", and Rockwell axles, these lockers provide a simple, durable, and proven solution for maximizing traction and drivetrain performance.
Which Traction is Right for Your Build?
| Feature | Steel Spool | Automatic Locker | Selectable Air Locker |
|---|---|---|---|
| Traction | 100% locked all the time | Locks under power | Driver controlled |
| Street Manners | Poor | Moderate | Best |
| Off-Road Traction | Maximum | Excellent | Excellent |
| Turning Ability | Most difficult | Better than spool | Best when unlocked |
| Complexity | Lowest | Medium | Highest |
| Maintenance | Lowest | Moderate | More components |
| Best For | Race-only, mud trucks, rock bouncers | Trail rigs, crawlers, off-road trucks | Dual-purpose rigs, overland, street/trail |
| Cost | Lowest | Medium | Highest |