ARB RD100 Air Locker - Dana 30 Front Axle Locker for Jeep Wrangler JK/JL

An open differential has one flaw that always shows up at the worst possible moment: the second one front wheel loses grip - hung up on a rock, dropped in a rut, spinning in mud - all the power goes to that wheel and the truck stops moving. The RD100 fixes that on demand. It is a selectable locker you switch on from the cab exactly when you need it, and switch back off the moment you are back on pavement.

RD100 is the factory part number for the ARB Air Locker, one of the most recognized locking differentials in the off-road world and a staple in expedition-vehicle builds for decades. One thing worth knowing before you buy: the locking mechanism itself is air-actuated through a solenoid valve, and the cab switch simply triggers it electrically - so a separate air compressor is required to run it.

Key benefits

• 100% locked traction on demand - engage the RD100 and both front wheels turn at the same speed regardless of the grip each one has, so a wheel hanging in the air stops being a problem.
• Selectable, not automatic - you switch it on and off yourself from the cab, so on pavement and in normal driving the axle behaves like an open differential, without the handling quirks of automatic lockers.
• Steel construction with a long track record - the RD100 is the same unit shops have been installing for years on rigs built for expeditions and off-road competition.
• Complete activation kit - the box includes not just the locker itself but the activation switch, solenoid valve, air line and bulkhead fitting, so you are not hunting down those parts separately.

Technical specifications

• Type: selectable air-actuated locker (Air Locker), triggered by an electric cab switch
• Axle: Dana 30, front
• Axle shaft spline count: 27
• Ring & pinion gear ratio range: 3.73 and up
• Carrier input shaft diameter: 1.16 in
• Housing material: steel
• Kit includes: locking carrier, activation switch, solenoid valve, air line, bulkhead fitting
• Required separately: air compressor (not included in the kit)

Who it's for / applications

This specific listing in our store covers the Jeep Wrangler JK (2007-2017) and JL (2018+), the two generations that come from the factory with a Dana 30 front axle on 27-spline shafts. It earns its keep anywhere an open differential starts limiting where you can drive: rock crawling, deep mud, sand, and any situation where a single wheel loses contact with the ground. Worth noting: the ARB RD100 unit itself, built for the Dana 30 (27-spline, 3.73-and-up ratio), is also factory-compatible with other vehicles sharing that same axle - including the Jeep Cherokee XJ and the Jeep Liberty/Cherokee KJ (2002-2007) - though that falls outside the scope of this Wrangler-specific listing.

Installation / notes

This is not a bolt-in, twenty-minute part - the kit replaces the factory carrier inside the axle, so installation means pulling the diff cover, removing the axle shafts, taking out the old carrier and setting the new one with correct backlash and ring-and-pinion tooth contact, plus routing an air line to the compressor and wiring the cab switch. Because gear setup demands precision, we recommend having it installed by a shop experienced with off-road axles - our team at Szekla4x4.pl works on this kind of installation regularly and can help with both the locker itself and choosing a matching compressor.

Why it's worth it

• A long-proven ARB design known for holding up in serious terrain.
• Full control over when the locker engages - one switch, zero compromise on pavement manners.
• A complete activation kit in the box - the only thing you still need to add is a compressor.

Not sure if the RD100 is the right call for your Wrangler? Reach out or give us a call - we will confirm your axle and ratio match up and help you pick a compressor to go with it.

Frequently asked questions

Do I need anything else besides the locker itself for it to work?

Yes. The kit includes the locking carrier, activation switch, solenoid valve, air line and bulkhead fitting, but the air compressor itself is not included and must be bought separately - without it the RD100 will not engage.

Is this locker always on, or do I switch it myself?

It is a selectable locker - you engage and disengage it yourself with the cab switch exactly when you want it. With it switched off, the axle behaves like an open differential for everyday driving.

What axle and gear ratio does this unit fit?

The front Dana 30 axle with a 27-spline axle shaft, on a 3.73 or numerically higher ring and pinion ratio. Check both figures against your own vehicle before ordering.

Can I install it myself?

Installation means disassembling the axle, swapping the carrier with correct gear backlash, and wiring up both the air line and the electric switch, so we recommend a shop experienced with off-road axles - we handle this exact type of install at Szekla4x4.pl as well.

Does this specific listing fit only the Wrangler JK and JL?

In our store we carry this listing for the Wrangler JK (2007-2017) and JL (2018+). The ARB Dana 30 unit itself is also factory-compatible with other vehicles sharing that axle, but that is outside the scope of this listing - if you drive a different model, ask us before ordering.