Diff lockers are designed to provide maximum traction by locking both wheels on an axle together.
Unlike open diffs or limited slip diffs, which allow some difference in wheel speed, when a diff lock is engaged it forces both wheels to rotate at the same speed.
This ensures that if one wheel loses traction, the other wheel can still receive full torque from the drivetrain.
Diff lockers are commonly used in:
- Off-road vehicles
- Four-wheel-drive vehicles
- Rock crawling and extreme terrain applications
How a Standard Diff Works
A normal diff allows the two wheels on an axle to rotate at different speeds. This is necessary when the vehicle is turning, as the outside wheel travels further than the inside wheel.
However, the downside of an open differential is that torque will follow the path of least resistance.
If one wheel loses traction, the majority of the torque can be sent to the slipping wheel, leaving the wheel with grip unable to move the vehicle.
How a Diff Locker Works
A differential locker eliminates this problem by mechanically locking the axle shafts together.
When engaged, the locker locks both wheels together so they turn at the same speed for maximum traction.
Even if one wheel has little or no traction, the wheel with grip can still receive torque and move the vehicle forward.
Types of Differential Lockers
The most common types of differential lockers include:
- Air Lockers
- Electronic Lockers (E-Lockers)
- Mechanical Lockers (Auto Lockers)
Each type uses a different method to lock the differential.
Air Lockers
Air lockers use compressed air to engage the locking mechanism inside the differential.
When activated, air pressure moves an internal locking collar that locks the differential gears together.
Well known air locker brands are:
- ARB air locker
- TJM Pro Locker
- Yukon Ziplocker
- HF Air locker
Electronic Lockers (E-Lockers)
Electronic lockers use an electric actuator or electromagnet to engage the locking mechanism inside the differential.
Well-known electronic locker systems include:
- Harrop ELocker
- Eaton ELocker
- Most factory style lock diffs (Toyota, Ford etc)
These lockers are usually controlled by a dashboard switch.
Mechanical Lockers (Auto Lockers)
Mechanical lockers operate without air or electrical systems.
They automatically lock the axle shafts together when torque is applied.
Common examples include:
- Detroit Locker
- Lokka
- Yukon Grizzly Locker
When Are Diff Lockers Used
Differential lockers are primarily used when maximum traction is required, such as:
- Off-road driving
- Rock crawling
- Mud or loose terrain
- Situations where wheels may lift off the ground
Choosing the Right Diff Locker
The best type of locker depends on the vehicle and how it is used.
Air lockers provide strong locking with driver control.
Electronic lockers offer convenient operation and in our opinion less to go wrong.
Mechanical lockers (Auto lockers) Simple installation, but generally not as smooth in operation as other locker types.
At Gearhead Diffs we supply and install a wide range of differential upgrades including lockers and limited slip differentials.