Non-Rubicon JLs have an open Dana 44 M220 rear axle that benefits enormously from a locker; Eaton's 14234-1 ELocker is the direct-fit electric answer ($1,100), ARB's RD-245 is the air-actuated alternative if you already run a compressor.
The JL rear axle is a Dana 44 in name only — the housing is the M220 variant, beefier than the front M210 but with its own carrier specs and spline counts. Rubicons come with the OE Tru-Lok electric locker from the factory. Sport, Sport S, Sahara, and Willys come with an open differential (Sahara is sometimes Trac-Lok limited-slip) and a 30- or 32-spline carrier depending on year and gear ratio. Knowing exactly what you have determines which locker fits.
Eaton's ELocker is the most common upgrade because it's electric, one-wire activation, and doesn't require an air compressor. The 14234-1 fits 35-spline M220 carriers on 2018–2023 JL/JT non-Rubicons. The newer 14313-2 covers later model years through 2026. The 19977-010 is the performance 4-pinion option for older 30-spline D44s with 3.73 or numerically lower gears — relevant only if you're running an older D44 conversion or stock gears. Get the spline count from your build sheet or, more reliably, by pulling the diff cover and counting splines on the side gears.
ARB Air Lockers are the air-actuated alternative. The RD-245 fits 30-spline factory-CV Dana 44s and costs $1,091 plus another $340 for the compressor (CKMA12) if you don't have one. Two locker reasons to choose ARB: you want full-open behavior on the street (ELockers are also open until engaged, so this is a wash), and you want the option to add a front ARB later sharing the same compressor. If you're already running OBA for tires, the ARB compressor is a no-cost adder.
Install is not a beginner job. You're pulling the carrier, swapping in the locker, setting pinion preload, ring gear backlash (0.005–0.008"), and pinion bearing crush (~15 in-lb rolling torque used). If you're not regearing at the same time, you can re-use the existing ring gear if it's not worn — but most shops will tell you to regear during the locker install since the carrier is out anyway. If this is your first gear setup, pay a driveline shop. Bad setup eats a $1,100 locker.
| Part | Vendor | Est. price |
|---|---|---|
| Eaton ELocker — Dana 44 M220 35-spline (Non-Rubicon JL/JT) | Eaton | ~$1100 |
| Eaton ELocker — Dana 44 M220 35-spline (alt p/n) | Eaton | ~$1150 |
| Eaton Performance ELocker — 30-spline D44, 3.73 and lower | Eaton | ~$900 |
| ARB Air Locker RD-245 — Dana 44 30-spline w/factory CV | ARB | ~$1091 |
| ARB compact onboard compressor (CKMA12) | ARB | ~$340 |
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.