ARB Dana 44 Air Locker Differential - 3.73 & Down, 30-Spline, RD117
RD117
The ARB RD117 Dana 44 Air Locker Differential delivers selectable, 100% locking traction for compatible 30-spline Dana 44 axles using the 3.73-and-down carrier configuration. Designed for Jeep, Ford, classic truck, and custom off-road axle applications, this air-operated locking differential allows both axle shafts to be locked together when maximum traction is needed. When disengaged, the Air Locker operates as a conventional open differential, maintaining predictable handling and normal differentiation between the wheels.
Built with ARB's proven pneumatic locking mechanism, heavy-duty differential case, and precision-engineered internal components, the RD117 is suited for rock crawling, trail riding, off-road restoration, and custom axle builds. Its 3.73-and-down carrier configuration can also accommodate compatible thick-cut ring and pinion gear sets when designed for this carrier offset. Selecting the correct locker requires verifying axle spline count, ring gear design, gear ratio, and mounting hardware rather than relying on vehicle model alone.
Includes:
- (1) ARB RD117 Dana 44 Air Locker Differential Assembly
- (1) Dash-Mounted Activation Switch
- (1) Solenoid Valve
- Air Line and Bulkhead Fitting Assembly
- Carrier Bearings and Installation Shims
- Installation Hardware and Instructions
Important: An ARB Air Compressor is recommended for operation and sold separately. Verify the 30-spline axle configuration, carrier break, ring gear offset, and ring gear bolt diameter before ordering.
Specifications
| Manufacturer | ARB |
|---|---|
| Part Number | RD117 |
| Product Type | Selectable Air Locker Differential |
| Axle Platform | Dana 44 |
| Ring Gear Diameter | 8.5" (216mm) |
| Ring Gear Inside Diameter | 5.56" (141.3mm) |
| Ring Gear Bolt Count | 10 |
| Ring Gear Bolt Circle | 6.61" (168mm) |
| Axle Spline Count | 30-Spline |
| Axle Shaft Diameter | 1.31" (33.3mm) Nominal |
| Carrier Configuration | 3.73 & Down |
| Gear Ratio Compatibility | 3.73 & Down Standard Gear Sets; Compatible Thick-Cut Gear Sets Using the 3.73-and-Down Carrier Offset |
| Ring & Pinion Gear Cut | Standard-Offset or Compatible Thick-Cut, Application Dependent |
| Ring Gear Bolt Compatibility | 3/8", 7/16", or 1/2" Depending on Application |
| Flange Modification | Drilling or Reaming Required for 7/16" or 1/2" Ring Gear Bolts |
| Locker Type | Selectable Air Locker |
| Activation | Pneumatic / Air Operated |
| Unlocked Operation | Open Differential |
| Locked Operation | 100% Locked |
| Differential Design | ARB Air-Actuated Locking Carrier |
| Axle Position | Front or Rear, Depending on Axle Application |
| Carrier Bearings | Included |
| Installation Shims | Included |
| ABS Tone Ring | Compatible Where Applicable |
| Air Supply | ARB Air Compressor or Compatible Air Source |
| Minimum Alternate Air Pressure | 85 PSI |
| Installation Type | Replacement Differential Carrier / Professional Setup Recommended |
| Primary Application | Dana 44 30-Spline Axles, Jeep and Ford Off-Road Builds, Custom Axle Assemblies |
Manufacturer Setup Reference:
- Ring Gear Bolt Torque, 3/8": 55 ft-lb (75 Nm)
- Ring Gear Bolt Torque, 7/16": 100 ft-lb (136 Nm)
- Ring Gear Bolt Torque, 1/2": 130 ft-lb (176 Nm)
- Backlash: 0.006"–0.010" (0.15–0.25mm)
- Bearing Cap Torque: 60 ft-lb (81 Nm)
Reference values from the ARB RD117 installation guide. Follow the applicable vehicle service manual and current ARB installation instructions for final differential setup.
Fitment
Fitment is conditional on the installed axle and differential configuration. Not every vehicle, trim, or model year listed is equipped with a compatible Dana 44 axle.
| Make | Model | Year Range | Axle Application |
|---|---|---|---|
| Chevrolet | K10 / K20 / K5 Blazer / Suburban | 1979–1980 | Dana 44 Configuration Required |
| Dodge | Ram 1500 | 1994–2001 | Dana 44 Configuration Required |
| Dodge | Ram 2500 | 1994–1998 | Dana 44 Configuration Required |
| Dodge | Ramcharger | 1981–1993 | Dana 44 Configuration Required |
| Dodge | W100 / W150 / W250 | 1984–1993 | Dana 44 Configuration Required |
| Ford | Bronco | 1980–1996 | Dana 44 Configuration Required |
| Ford | Bronco II | 1984–1990 | Verify Differential Configuration |
| Ford | F-150 | 1982–1996 | Dana 44 Configuration Required |
| Ford | F-250 | 1980–1990 | Dana 44 Configuration Required |
| Isuzu | Rodeo | 1999–2004 | Verify Differential Configuration |
| Isuzu | Rodeo Sport | 2001–2003 | Verify Differential Configuration |
| Jeep | Cherokee | 1984–1991 | Dana 44 Configuration Required |
| Jeep | Comanche | 1986–1992 | Dana 44 Configuration Required |
| Jeep | J10 | 1984–1987 | Dana 44 Configuration Required |
| Jeep | Wagoneer | 1979–1990 | Dana 44 Configuration Required |
| Jeep | Wrangler / TJ | 1997–2006 | Dana 44 Configuration Required |
| Jeep | Wrangler JK Non-Rubicon | 2007–2018 | Dana 44 Configuration Required |
Required Axle Specifications:
- Dana 44 differential platform
- 30-spline axle shafts
- 3.73-and-down carrier configuration
- Compatible ring gear offset and mounting dimensions
- Correct ring gear bolt diameter and mounting pattern
Important Fitment Notes:
- Standard-offset 3.92 & up Dana 44 gear sets require ARB RD116 instead.
- Compatible thick-cut ring and pinion sets designed for the 3.73-and-down carrier offset may use RD117.
- Some Dana 44 ring gears use 3/8", 7/16", or 1/2" mounting bolts.
- The Air Locker flange must be drilled or reamed to accommodate 7/16" or 1/2" ring gear bolts according to ARB instructions.
- Ford Dana 44 IFS applications may require an alternative axle shaft retention method because the factory C-clip cannot be reused.
Builder Note: Always verify the actual axle platform, spline count, carrier break, ring gear configuration, and mounting hardware before ordering. Factory axle options and aftermarket axle swaps can affect compatibility.
FAQ
What Dana 44 axles does the ARB RD117 fit?
The RD117 is designed for compatible Dana 44 differentials with 30-spline axle shafts and the 3.73-and-down carrier configuration. Verify the installed axle, ring gear offset, and shaft specifications before ordering.
What is the difference between ARB RD116 and RD117?
Both are selectable Dana 44 Air Lockers for compatible 30-spline axle configurations. RD117 uses the 3.73-and-down carrier offset, while RD116 is designed for 3.92-and-up standard-offset gear sets. Compatible thick-cut higher-ratio gear sets may use RD117 when manufactured for the lower-ratio carrier offset.
Can I use RD117 with 4.56, 4.88, or 5.13 gears?
Only when using a compatible thick-cut ring and pinion gear set designed for the 3.73-and-down carrier offset. Standard-offset 3.92-and-up gear sets require RD116. Always confirm the ring gear design with the gear manufacturer.
Will RD117 fit a Jeep Wrangler Dana 44?
Fitment depends on the specific Dana 44 assembly. Verify the axle shaft spline count, carrier break, ring gear mounting dimensions, and axle generation. Do not assume compatibility based solely on the Wrangler model name.
Can the RD117 be installed in a front or rear Dana 44 axle?
It can be used in compatible front or rear Dana 44 applications when the required carrier, shaft, and ring gear specifications are met. Some front axle designs have additional shaft retention requirements.
Does the RD117 fit a Ford Dana 44 IFS axle?
ARB documents a special installation requirement for certain Ford Dana 44 independent front suspension assemblies. The original axle retaining C-clip cannot be reused, and an alternative spring-loaded retention arrangement is required. Consult the RD117 installation guide before installation.
Does RD117 include carrier bearings?
Yes. The ARB RD117 installation guide lists two tapered roller carrier bearings and installation shim components as part of the kit.
Will I need to modify the ring gear mounting holes?
Possibly. Dana 44 ring gears may use 3/8", 7/16", or 1/2" bolts. ARB specifies enlarging the locker flange holes for the larger bolt diameters. Follow the manufacturer's instructions and verify the hardware before assembly.
Does the ARB RD117 require an air compressor?
Yes. The locker requires compressed air to engage. ARB recommends its air compressor system, which is sold separately. The kit includes the switch, solenoid, air line, and bulkhead connection components.
Is the ARB Dana 44 Air Locker suitable for street driving?
Yes. When disengaged, the Air Locker operates as an open differential, allowing normal wheel-speed differences during turns. It provides full locking traction when engaged for appropriate off-road conditions.
