Engaging only the rear locker is often the right call on trail — it provides the traction benefit with more steering ability than running front and rear locked together. Knowing when to use what is more valuable than knowing how to engage everything at once.
The Rubicon runs electronic lockers in both the front Dana 44 and the rear Dana 44. These are selectable differential locks — when engaged, both wheels on that axle are driven at the same speed regardless of traction conditions. The lockers can be engaged independently via the instrument cluster controls.
The system operates in 4L (low range) by default for full locker engagement. The rear locker can be engaged in 4H on some terrain conditions.
Moderate trail with steering demands: When you need traction but also need to steer precisely — navigating around obstacles, threading a line through loose rock — rear-only lock provides drive traction through the rear axle while leaving the front axle free to respond to steering inputs. Locking the front as well reduces steering feel and creates understeer on tight turns.
Mud and loose terrain: In deep mud or loose dirt, the rear locker keeps the rear wheels driving together without spinning down. The front axle in open-diff mode can still find traction and contribute, while the rear pushes. This is often enough to get through without front lock.
Highway-adjacent situations: If you find yourself in a difficult low-speed situation on or near pavement (a steep gravel driveway, a muddy turnaround), rear-only lock in 4H can provide the traction you need without forcing the front diff to fight the drivetrain binding that full lock creates on hard surfaces.
Add the front locker when rear-only isn't enough — typically:
With both lockers engaged, the steering fights back. The truck wants to go straight; turning requires more input and creates axle binding on tight turns. On slick rock this binding is managed by terrain flex. On hard-pack or pavement, binding is uncomfortable and puts stress on the drivetrain.
Drive full-locked at low speed, on terrain that justifies it, and unlock before returning to any hard surface.
For reference on trail approach:
| Axle Setup | Description | Trail Use |
|---|---|---|
| Open differential | Torque goes to the wheel with least resistance — worst case, one spinning wheel | Fine for mild trail |
| Limited-slip (LSD/Trac-Lok) | Biases torque toward the wheel with more traction — better than open | Good for moderate terrain |
| Locked differential | Both wheels driven at equal speed regardless of traction | Maximum traction, reduced steering |
The Rubicon's electronic lockers are true lockers — not limited-slip. Engage them for terrain that demands it, not as a default trail setting.
Before you reach for a locker, understand what the Gladiator already does automatically. Every JT runs brake-lock differential (BLD) traction control — the ABS system pulses the brake on a spinning wheel to send torque across an open diff to the wheel with grip. On mild trail, BLD alone handles a lot: a single lifted tire on a rutted climb often gets sorted by the electronics before you'd ever think to lock.
Where BLD runs out is sustained, high-load slip. It's reactive and it works through the brakes, so it heats up and fades on a long, slow, one-wheel-spinning crawl. A mechanical or electronic locker doesn't fade — it physically ties the axle shafts together and holds. That's the dividing line: BLD for intermittent traction loss, a locker for terrain where you'll be putting steady torque through a lifted or low-grip wheel for more than a few seconds.
One more interaction worth knowing: engaging the rear locker on the Rubicon automatically relaxes some of the stability-control intervention, because the truck no longer needs to brake a "spinning" rear wheel that's now locked to its partner. That's by design — let the locker do the mechanical work and stop fighting the brakes. If you're adding a locker to a non-Rubicon trim, see the full install and hardware options in Rear Locker for the Gladiator JT — Dana 44 Options.
Written and maintained by an AZ wheeler and driveway wrencher. Always cross-reference your factory service manual — modifications affect vehicle safety and warranty. Work at your own risk.
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