ARB Dana 30 Air Locker Differential - Jeep CJ, Cherokee, & Wrangler, 3.73 & Up, 27-Spline
RD100
The ARB RD100 Dana 30 Air Locker Differential is a selectable, air-operated locking differential engineered to deliver maximum traction on demand in compatible 27-spline Dana 30 front axle applications. Designed for Jeep Wrangler, Cherokee, Grand Cherokee, Liberty, classic Jeep CJ, and select Ford Bronco applications, the RD100 allows drivers to engage a fully locked differential at the flip of a switch. When activated, compressed air engages the internal locking mechanism, forcing both axle shafts to rotate together for improved traction in rocks, mud, snow, and demanding off-road terrain.
When disengaged, the ARB Air Locker operates as a conventional open differential, allowing normal wheel-speed differentiation and predictable steering during everyday driving. Its precision-machined differential case, forged alloy internal components, patented locking mechanism, and air-actuated engagement system are engineered for demanding trail and off-road use. The RD100 is listed by ARB for multiple Dana 30 front axle configurations, including select Dana 30 7.2" and M186 applications.
Includes:
- (1) ARB RD100 Dana 30 Air Locker Differential Assembly
- (1) Front Air Locker Activation Switch
- (1) 12V Air Solenoid Valve
- (1) Nylon Air Line
- (1) Bulkhead Fitting Kit
- Carrier Bearings and Installation Shims
- Installation Hardware and Instructions
Important: A compatible ARB Air Compressor is required for operation and is sold separately. Verify the installed axle configuration and gear ratio compatibility before ordering.
Specifications
| Manufacturer | ARB |
|---|---|
| Part Number | RD100 |
| Product Type | Selectable Air Locking Differential |
| Axle Platform | Dana 30 / Select Dana 30 7.2" & M186 Applications |
| Axle Position | Front |
| Axle Spline Count | 27-Spline |
| Axle Shaft Diameter | 1.16" (29.5mm) |
| Ring Gear Diameter | 7.2" (183mm) - RD100 Installation Manual Specification |
| Ring Gear Inside Diameter | 4.50" (114.3mm) |
| Ring Gear Bolt Count | 10 |
| Ring Gear Bolt Circle | 5.25" (133mm) |
| Gear Ratio Compatibility | 3.73 & Up for Standard RD100 Dana 30 Application; Additional ARB-Listed Configurations Require Verification |
| Differential Type | Selectable Air Locker |
| Differential Operation | Open When Disengaged / Fully Locked When Engaged |
| Activation Type | Pneumatic / Compressed Air |
| Activation Control | Dash-Mounted Electrical Switch |
| Differential Construction | Precision-Machined Metal Carrier Assembly |
| Internal Gear Design | Forged Alloy Gear Components |
| Locking Mechanism | Patented Air-Actuated Mechanical Locking System |
| Air Seal Design | Bonded Annular Seal with O-Ring Seal Housing |
| Color | Silver |
| Material | Steel / Metal Differential Assembly |
| Installation Type | Differential Carrier Replacement with Air System Installation |
| Primary Application | 27-Spline Dana 30 Front Axle Traction Upgrades for Compatible Jeep, Ford Bronco & Custom Off-Road Builds |
| Required Components | Compatible Air Compressor, Air Supply, Differential Lubricant & Installation Components |
| Quantity | One Selectable Locking Differential Assembly |
ARB RD100 Installation Manual Specifications:
- Ring Gear Bolt Torque: 55 ft-lb (75 Nm)
- Ring & Pinion Backlash: 0.006"–0.010" (0.15–0.25mm)
- Bearing Cap Torque: 60 ft-lb (81 Nm) for applicable cast-iron housings
- Aluminum housings require the vehicle manufacturer's specified bearing cap torque.
- ARB recommends professional installation and following the vehicle manufacturer's service manual.
Fitment
The ARB RD100 is listed for compatible 27-spline Dana 30 front axle applications. ARB identifies several axle configurations, so the installed differential must be verified before selecting this locker.
ARB-Listed Axle Configurations:
| Axle Platform | Position | Spline Count | Gear Ratio Listing |
|---|---|---|---|
| Dana 30 | Front | 27 | 3.73 & Up |
| M186 | Front | 27 | All Ratios - Verify Application |
| Dana 30 7.2" | Front | 27 | 3.54 & Down - Verify Application |
| Dana 30 7.2" | Front | 27 | 3.73 & Up |
| Dana 30 7.2" | Front | 27 | All Ratios - Verify Application |
Important Gear Ratio Note: ARB's RD100 installation manual specifies 3.73-and-up Dana 30 gearing and identifies RD101 for 3.54-and-down applications. Although the ARB product listing also displays additional ratio categories, these should not be interpreted as universal interchangeability. Confirm the exact axle and carrier configuration with ARB before ordering a 3.54-and-down application.
Vehicle Applications:
| Make | Model | Year Range | Axle Application |
|---|---|---|---|
| Ford | Bronco | 1966–1971 | Dana 30 Front |
| Jeep | CJ5 | 1971–1983 | Dana 30 Front |
| Jeep | CJ6 | 1971–1975 | Dana 30 Front |
| Jeep | CJ7 | 1976–1986 | Dana 30 Front |
| Jeep | Scrambler CJ8 | 1981–1985 | Dana 30 Front |
| Jeep | Wagoneer / Cherokee SJ | 1981–1983 | Dana 30 Front - Verify Axle |
| Jeep | Cherokee XJ | 1984–2001 | Dana 30 Front |
| Jeep | Comanche MJ | 1986–1992 | Dana 30 Front |
| Jeep | Wrangler YJ | 1987–1995 | Dana 30 Front |
| Jeep | Grand Cherokee ZJ / WJ | 1993–2004 | Dana 30 Front - Verify Axle |
| Jeep | Wrangler TJ / Unlimited LJ | 1997–2006 | Dana 30 Front - Verify Axle |
| Jeep | Liberty KJ / KK | 2002–2012 | Dana 30 IFS - Verify Configuration |
| Jeep | Wrangler JK Sport / Sahara / Non-Rubicon | 2007–2018 | Dana 30 Front - Verify Configuration |
| Jeep | Wrangler JL Sport / Sport S / Sahara / Willys | 2018–2023 | M186 Front - Verify Configuration |
Fitment Notes:
- Requires a compatible 27-spline front axle differential configuration.
- Standard Dana 30 RD100 installation manual specifies 3.73-and-up gearing.
- ARB also lists M186 and additional Dana 30 7.2" configurations; verify exact application.
- Not every vehicle listed uses the same differential or ring gear mounting design.
- Jeep JK and JL applications must be verified against their specific axle generation.
- Jeep Liberty IFS applications require confirmation of the aluminum front differential housing and carrier configuration.
- Jeep Rubicon models equipped with factory Dana 44 front axles require a different Air Locker application.
- Confirm axle shaft spline count, ring gear dimensions, carrier compatibility, and current gear ratio before ordering.
- Air compressor required and sold separately.
- Professional installation is recommended.
Builder Note: Dana 30 is a broad axle family used across multiple generations of Jeeps and other 4x4 vehicles. Carrier designs, ring gear mounting, axle shaft configurations, and housing construction can vary significantly. Always identify the installed axle rather than selecting a locker based only on vehicle year or model.
FAQ
What axles does the ARB RD100 Air Locker fit?
The RD100 is designed for compatible 27-spline Dana 30 front axle applications. ARB also lists select M186 and Dana 30 7.2" configurations. Exact compatibility depends on axle design, ring gear mounting, and gear ratio.
Will the RD100 fit my Jeep Wrangler TJ or Cherokee XJ?
Yes, the RD100 is listed for compatible Dana 30 front axle applications found in Jeep Wrangler TJ and Cherokee XJ vehicles. Verify the installed axle, spline count, and gear ratio before ordering.
Does the RD100 fit Jeep Wrangler JK models?
ARB lists compatible Jeep Wrangler JK applications, but the installed front axle must be verified. Dana 30 configurations can differ between vehicle generations, and factory Rubicon Dana 44 axles require a different locker.
Can the RD100 fit a Jeep Wrangler JL with an M186 front axle?
ARB's product information includes M186 front axle applications with 27-spline shafts. Confirm the exact M186 carrier and ring gear configuration before ordering, as M186 applications should not automatically be treated as interchangeable with earlier Dana 30 axles.
Will this Air Locker fit a Jeep Liberty front differential?
ARB's RD100 installation guide includes procedures for aluminum-housing Dana 30 independent front suspension applications, including Jeep Liberty KJ-style configurations. Verify the specific differential housing and carrier before ordering.
What gear ratios are compatible with the ARB RD100?
The RD100 installation manual specifies 3.73 and numerically higher gear ratios for its standard Dana 30 configuration. ARB's product listing also references additional axle and ratio combinations. For 3.54-and-down Dana 30 gearing, the installation manual directs customers to RD101. Confirm the correct locker for your exact application.
What is the difference between RD100 and RD101?
The RD100 installation manual identifies RD100 for Dana 30 applications using 3.73-and-up gearing and directs 3.54-and-down applications to RD101. Carrier breaks determine how the ring gear mounts to the differential, making proper ratio selection critical.
Does the RD100 require an air compressor?
Yes. A compatible compressed air supply is required to activate the locker. ARB recommends using an ARB air compressor, which is sold separately.
Can the RD100 operate with an aftermarket air compressor?
ARB's installation manual allows an alternate air source if it supplies clean air at a minimum of 85 PSI, has sufficient capacity to actuate the locker, and connects properly to the solenoid. ARB recommends its own compressors and warns that damage caused by an unsuitable alternate air supply may not be covered under warranty.
How does the ARB RD100 Air Locker work?
Compressed air