Eaton Elocker4 Differential 27 Spline 3.73 Ratio Dana 30
A Dana 30 front axle with an open differential sends power to whichever front tire has the least grip, so one wheel spins in the air while the other does nothing. The Eaton ELocker4 19818-020 replaces the open carrier in a 27-spline Dana 30 geared 3.73 or numerically higher with a selectable locker: it drives like an open diff on the street and locks both front axle shafts together at the flip of a switch. It is a common upgrade for Jeep Wrangler JK and non-Rubicon JL owners who already run 4.10, 4.56 or 4.88 gears.
When the switch is off, the ELocker behaves as a normal open differential, so steering and tire wear are unaffected on pavement. When you switch it on, an electromagnetic coil drives a ball-ramp that pushes a locking ring into engagement with one side gear, which ties the side gear to the case. Both front wheels then turn at the same speed regardless of traction. The "4" means a four-pinion cross arrangement inside the case. It runs on 12 volts and comes with a wiring harness, a switch and a relay; Eaton says current draw is roughly 5 to 10 amps, so use the relay rather than running the coil straight through the switch.
Three things decide fitment: the axle must be a Dana 30 with a 7.2 inch ring gear, the axle shafts must have 27 splines, and the gear ratio must be 3.73 or numerically higher. Ratios of 3.54 and lower use a different carrier break, so trucks still on the factory 3.21 or 3.54 gears need the ELocker4 for 3.54 and lower ratios or need re-gearing first. Read the axle tag or count turns with the front end on stands. If you are re-gearing at the same time, set up the new JK/JL reverse Dana 30 4.88 ring and pinion on this carrier during the same job.
Catalog fitment for 19818-020 covers 2007-2018 Jeep Wrangler JK and 2018-up Wrangler JL front Dana 30 axles, excluding Rubicon models, which use a Dana 44 front. Some catalogs also list earlier YJ, TJ and XJ 27-spline Dana 30 fronts. It is not listed for the Gladiator JT. Since axles get swapped and re-geared, confirm the ring gear ratio and spline count on your actual axle, or send us your year and VIN and we will check it.
Keep the Eaton ELocker service kit for Dana 30/35 in mind for later electrical repairs, and if the axle seals are leaking while the shafts are out, the inner axle seal installer makes replacement easy. Browse more drivetrain parts on the hard parts page.
| Brand | Eaton |
| Part number | 19818-020 |
| Fits | Eaton Elocker4 Differential 27 Spline 3.73 Ratio Dana 30 |
| Type | Differentials |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. Wrangler Rubicon models use a Dana 44 front axle. This unit is for 27-spline Dana 30 axles such as non-Rubicon JK and JL fronts.
Not with those gears. 19818-020 is for 3.73 and numerically higher ratios. With 3.54 or lower, use the 19817-020 version or re-gear the axle first.
No. Carrier bearing LM102949, race LM102911 and outboard shims are required and sold separately. Many owners install a master overhaul kit at the same time.
Engage it only when stopped or moving below about 5 mph with both wheels turning at nearly the same speed. Turn it off on pavement so the front axle can differentiate in turns.
No. It is electrically actuated by a 12 volt coil, using the included harness, switch and relay.
