ARB Dana M220 Rear Air Locker Differential - Jeep JL 32-Spline
RD245
The ARB RD245 Air Locker Differential is a selectable locking differential designed for compatible Jeep Wrangler JL and Gladiator JT Dana M220 rear and Dana M210 front axles with 32-spline shafts. Built to deliver maximum traction on demand, this air-operated locker allows drivers to engage both axle shafts at the flip of a switch, improving control through rocks, mud, sand, steep climbs, and technical off-road terrain. It's an excellent upgrade for Jeep JL Sport and Sahara builds, Gladiator trail rigs, overland vehicles, and custom axle applications that need dependable traction without permanently locking the differential.
When activated, compressed air engages ARB's internal locking mechanism, forcing both axle shafts to rotate together for fully locked traction. Its durable two-piece steel carrier, patented timed locking mechanism, and reinforced annular air seal are engineered for reliable operation under demanding off-road conditions. Compatible with all gear ratios in supported axle configurations, the RD245 provides selectable traction while retaining normal differential operation when switched off.
Includes:
- (1) ARB RD245 Air Locker Differential Assembly
- (1) Dash-Mounted Activation Switch
- (1) Air Solenoid Valve
- Air Line
- Bulkhead Fitting
Important: A compatible ARB Air Compressor is required for operation and is sold separately. This locker requires a compatible Dana M210 or M220 differential with 32-spline axle shafts. Factory Rubicon electric-locker axle shafts are not directly compatible and require replacement for RD245 installation.
Specifications
| Manufacturer | ARB |
|---|---|
| Part Number | RD245 |
| Product Type | Selectable Air Locking Differential |
| Axle Platform | Dana M210 / Dana M220 |
| Ring Gear Diameter | 220mm / 8.66" (M220) |
| Axle Position | Front or Rear - Application Dependent |
| Axle Spline Count | 32-Spline |
| Shaft Diameter | 1.41" / 35.8mm |
| Gear Ratio Compatibility | All Ratios |
| Carrier Compatibility | Compatible Dana M210 / M220 32-Spline Applications |
| Differential Operation | Selectable Open / Fully Locked |
| Engagement Type | Pneumatic / Compressed Air |
| Carrier Construction | Two-Piece Steel Carrier |
| Material | Steel |
| Finish | Silver |
| Installation Type | Replaces Factory Differential Carrier |
| Primary Application | Jeep Wrangler JL & Gladiator JT Front or Rear Differential Traction Upgrades |
| Required Components | Compatible Air Compressor, 32-Spline Axle Shafts & Differential Installation Components |
| Known Incompatibilities | Dana M186 / M200 Axles; 27-, 29- & 35-Spline Shafts; Factory Rubicon Locker Shafts Without Replacement |
| Quantity | One Selectable Air Locker Assembly |
Fitment
Designed for compatible Dana M220 rear and Dana M210 front axle applications with 32-spline shafts. Jeep Wrangler JL models use different axle configurations depending on trim, engine, transmission, and factory differential options. Verify the installed axle before ordering.
| Make | Model | Year Range | Axle Application |
|---|---|---|---|
| Jeep | Wrangler JL Sport / Sport S | 2018–Present | Dana M220 Rear - Equipped Models Only |
| Jeep | Wrangler JL Unlimited Sport / Sport S | 2018–Present | Dana M220 Rear - Equipped Models Only |
| Jeep | Wrangler JL Unlimited Sahara | 2018–Present | Dana M220 Rear - Equipped Models Only |
| Jeep | Wrangler JL Diesel Models | 2020–2023 | Dana M210 Front / M220 Rear - Verify Configuration |
| Jeep | Gladiator JT Sport / Sport S | 2020–Present | Dana M210 Front / M220 Rear - 32-Spline |
| Jeep | Gladiator JT Overland | 2020–Present | Dana M210 Front / M220 Rear - 32-Spline |
| Jeep | Gladiator JT Non-Rubicon Models | 2020–Present | Dana M210 Front / M220 Rear - Verify Configuration |
Fitment Notes:
- Fits compatible Dana M220 rear differentials using 32-spline axle shafts
- Fits compatible Dana M210 front differentials using 32-spline axle shafts
- Compatible with all gear ratios in supported axle configurations
- Jeep JL Sport and Sahara models must have the M220 rear axle
- Jeep JL models equipped with the M200 rear axle require a different locker
- Non-Rubicon Jeep Gladiator JT models with factory M210 front and M220 rear axles are supported
- Not a direct-fit replacement for factory JL or JT Rubicon electric lockers
- Rubicon conversions require compatible replacement axle shafts and may require additional electronic modifications
- Factory Rubicon electric-locker axle shafts cannot be reused directly with RD245
- Requires a compatible compressed air supply; compressor sold separately
- Verify axle identification, spline count, ring gear mounting configuration, and axle shaft lengths before ordering
- Professional differential installation and air line routing are recommended
Builder Note: Not every Jeep JL Sport or Sahara has the same rear axle. The Dana M200 uses 29-spline shafts, while the Dana M220 uses 32-spline shafts. The RD245 is intended for the M220 configuration. For Rubicon builds, factory electric-locker axle shaft lengths differ from standard non-locker applications, so a direct locker replacement requires additional planning and compatible shafts.
FAQ
What does the ARB RD245 Air Locker do?
The ARB RD245 is a selectable locking differential that allows the driver to switch between normal open differential operation and fully locked traction. When activated, compressed air engages the internal locking mechanism so both axle shafts rotate together, improving traction in demanding off-road conditions.
Will the ARB RD245 fit my Jeep Wrangler JL Sport or Sahara?
Yes, provided your Jeep has the compatible Dana M220 rear axle with 32-spline shafts. Some JL Sport and Sahara models use the smaller Dana M200 rear axle, which requires a different Air Locker. Verify your axle before ordering.
Will the RD245 fit a Jeep Gladiator JT?
Yes. ARB lists the RD245 for compatible 32-spline Dana M210 front and M220 rear axles used in non-Rubicon Jeep Gladiator JT models. Confirm the installed axle configuration before ordering.
Does the RD245 fit a Jeep JL Rubicon?
The RD245 is not a direct-fit replacement for the factory Rubicon electric locker. The original axle shafts have different lengths and cannot be reused directly. Compatible replacement 32-spline axle shafts and potentially additional electronic modifications are required for a conversion.
What is the difference between the Dana M200 and Dana M220 rear axles?
The Dana M200 is a smaller rear differential commonly equipped with 29-spline axle shafts, while the Dana M220 uses a larger differential and 32-spline shafts. The RD245 is designed for compatible M220 applications, not M200 axles.
Can the RD245 be installed in a Dana M210 front axle?
Yes. ARB lists RD245 for compatible 32-spline Dana M210 front axle applications, including non-Rubicon Jeep Gladiator JT models and select Wrangler JL configurations. Verify the axle and shaft specifications before installation.
Does the ARB RD245 require an air compressor?
Yes. A compatible ARB air compressor and air supply system are required to activate the locking mechanism. The compressor is sold separately.
What gear ratios are compatible with the RD245?
The RD245 supports all gear ratios in compatible Dana M210 and M220 differential applications. The ring and pinion must still match the correct axle housing and carrier mounting configuration.
Does the RD245 stay locked during normal driving?
No. When disengaged, the Air Locker operates as a conventional open differential. The driver activates the locker when additional traction is needed and disengages it for normal differential operation.
What is the difference between an ARB Air Locker and an automatic locker?
An ARB Air Locker gives the driver direct control over differential locking. Automatic lockers engage and disengage mechanically based on their internal design and driving conditions. Selectable operation allows improved control over traction and steering behavior, especially on technical trails.
Can I install the RD245 during a ring and pinion gear upgrade?
Yes. Installing the Air Locker during a gear change is practical because the differential carrier is already being removed. Correct bearing preload, backlash, and ring gear contact pattern must be established during installation.
Does the RD245 include the activation switch and air line?
Yes. The supplied kit contents include the Air Locker differential assembly, activation switch, solenoid valve, air line, and bulkhead fitting. The air compressor is sold separately.
