The Gladiator Rubicon already comes with Tru-Lok front and rear lockers — this guide is for Sport, Willys, Overland, and Mojave owners who want locking traction without stepping into Rubicon pricing.
The rear axle on all non-Rubicon JT trims is a Dana 44 with an open differential. An open diff is fine for pavement and light gravel, but on uneven terrain — a side slope where one rear tire lifts, or a muddy wash where traction is patchy — an open diff sends power to the spinning tire instead of the tire with grip. A locker eliminates that. It mechanically (or electronically) connects both rear axle shafts so they turn together regardless of traction difference between the tires.
The ARB Air Locker ($849) is the performance choice: a pneumatic locker that engages and disengages via air pressure, giving you a true open differential on pavement and a locked rear when you activate it on the trail. ARB Air Lockers require a 12V air compressor — ARB sells a compatible twin-cylinder compressor kit ($369) that mounts under the hood. The combined cost puts the full ARB setup at roughly $1,200, but the on-demand engagement is the only design that genuinely delivers both behaviors without compromise.
The Eaton ELocker ($649) uses an electric solenoid to lock the differential on demand. It's cleaner to install than the ARB (no air lines), engages nearly as quickly, and costs less. The primary downside is that solenoid failure (which is uncommon but not unheard of) leaves you with a locked rear until you diagnose and repair it — the ARB at least fails open. The Detroit Truetrac ($549) is a helical gear limited-slip, not a true locker — it won't mechanically lock both shafts, but it biases torque to the gripping tire more aggressively than an open diff. It's the choice for owners who want improved traction without any driver activation required and don't need a fully locked differential.
| Part | Vendor | Est. price |
|---|---|---|
| ARB Air Locker for Dana 44 Rear (JT compatible) | ARB | ~$849 |
| Eaton ELocker for Dana 44 Rear | Eaton | ~$649 |
| Detroit Truetrac Limited Slip for Dana 44 | Detroit Locker / Eaton | ~$549 |
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.