ARB GM 14-Bolt 10.5" Air Locker Differential - Full Float, 30-Spline, RD114
RD114
The ARB RD114 Air Locker Differential for GM 14-Bolt 10.5" Full-Float Rear Axles delivers selectable, 100% locking traction for heavy-duty trucks, rock crawlers, trail rigs, and custom off-road builds. Designed for 30-spline axle shafts, this air-operated locking differential replaces the factory carrier and allows the driver to lock both rear axle shafts together when maximum traction is needed. When disengaged, the Air Locker operates as a conventional open differential for predictable handling and reduced tire scrub.
Built for demanding GM 14-bolt applications, the RD114 features a heavy-duty differential case, a pneumatically operated locking mechanism, and ARB's proven internal gear and sealing system. The locker is designed around the 4.10-and-down carrier configuration, with 4.56-and-up ratios supported when using a compatible thick, high-offset aftermarket ring and pinion gear set. It is an excellent option for builders who want dependable traction without permanently locking the rear axle.
Includes:
- (1) ARB RD114 GM 14-Bolt 10.5" Air Locker Differential Assembly
- (1) Dash-Mounted Activation Switch
- (1) Solenoid Valve
- Air Line and Bulkhead Fitting Assembly
- Air Locker Installation Hardware
- Installation and Operating Instructions
Important: An ARB Air Compressor is required for operation and sold separately. Differential carrier bearings are not included. Verify the installed axle, 30-spline shaft configuration, and ring and pinion gear set before ordering.
Specifications
| Manufacturer | ARB |
|---|---|
| Part Number | RD114 |
| Product Type | Selectable Air Locker Differential |
| Axle Platform | GM 14-Bolt 10.5" Full Float |
| Axle Position | Rear |
| Ring Gear Diameter | 10.5" (267mm) |
| Ring Gear Inside Diameter | 6.4375" (163.513mm) |
| Ring Gear Bolt Count | 12 |
| Ring Gear Bolt Circle | 7.78" (197.6mm) |
| Axle Spline Count | 30-Spline |
| Axle Shaft Diameter | 1.54" (39.2mm) Nominal |
| Carrier Configuration | 4.10 & Down |
| Gear Ratio Compatibility | 4.10 & Down; 4.56 & Up With Compatible Thick, High-Offset Gear Set |
| Locker Type | Selectable Air Locker |
| Activation | Pneumatic / Air Operated |
| Unlocked Operation | Open Differential |
| Locked Operation | 100% Locked |
| Differential Construction | Heavy-Duty Steel Differential Assembly |
| Air Supply | ARB Air Compressor or Approved Compatible Air Source |
| Minimum Air Supply Pressure | 85 PSI for Alternate Air Sources |
| Carrier Bearings | Not Included |
| Installation Type | Replacement Differential Carrier / Professional Setup Recommended |
| Primary Application | GM 14-Bolt Full-Float Rear Axle, Heavy-Duty Trucks, Rock Crawlers, and Off-Road Builds |
Manufacturer Setup Reference:
- Ring Gear Bolt Torque: 120 ft-lb (163 Nm)
- Backlash: 0.005"–0.008" (0.13–0.20mm)
- Bearing Cap Torque: 135 ft-lb (183 Nm)
Fitment
Designed for GM 14-bolt 10.5" full-float rear axles with 30-spline shafts. The following vehicle applications are consolidated from the supplied fitment information. Not every vehicle within the listed year ranges was equipped with the required axle.
| Make | Model | Year Range | Axle Application |
|---|---|---|---|
| Chevrolet | C20 / K20 | 1985–1986 | GM 14-Bolt 10.5" Full Float Rear |
| Chevrolet | C20 / K20 Suburban | 1985–1986 | GM 14-Bolt 10.5" Full Float Rear |
| Chevrolet | C2500 / K2500 | 1989–2000 | GM 14-Bolt 10.5" Full Float Rear |
| Chevrolet | C2500 / K2500 Suburban | 1992–1999 | GM 14-Bolt 10.5" Full Float Rear |
| Chevrolet | C3500 / K3500 | 1989–2000 | GM 14-Bolt 10.5" Full Float Rear |
| Chevrolet | G20 / G30 Vans | 1985–1999 | GM 14-Bolt 10.5" Full Float Rear - Select Models |
| Chevrolet | P30 | 1997–1999 | GM 14-Bolt 10.5" Full Float Rear - Select Models |
| Chevrolet | Avalanche 2500 | 2002–2005 | GM 14-Bolt 10.5" Full Float Rear |
| GMC | C3500 | 1989–2000 | GM 14-Bolt 10.5" Full Float Rear |
| GMC | K2500 | 1989–2000 | GM 14-Bolt 10.5" Full Float Rear |
| GMC | G2500 / Vandura / Rally | 1989–1995 | GM 14-Bolt 10.5" Full Float Rear - Select Models |
| GMC | Yukon XL 2500 | 2000–2013 | GM 14-Bolt 10.5" Full Float Rear - Verify Axle |
| Custom Fabrication | Rock Crawlers / Off-Road Buggies | Universal | Compatible GM 14-Bolt 10.5" Full Float Rear Axle |
Required Axle Configuration:
- GM 14-Bolt 10.5" full-floating rear axle
- 30-spline axle shafts
- Compatible 4.10-and-down carrier configuration
- Compatible thick, high-offset aftermarket ring and pinion for 4.56-and-up ratios
Important Fitment Notes:
- Not compatible with GM 14-bolt 9.5" semi-float axles.
- Not compatible with GM 11.5" or other rear axle platforms.
- Not compatible with 40-spline axle shafts.
- Factory 4.56-and-up ring and pinion gear sets are not supported by this locker.
- Some axle housings require clearance modifications to accommodate the Air Locker assembly.
- Verify axle identification, spline count, ring and pinion type, and carrier configuration before ordering.
- Vehicle year, make, and model alone do not guarantee compatibility.
Builder Note: The GM 14-bolt has been used in several different configurations over the years. Confirm that your axle is the 10.5" full-float version with 30-spline shafts. If your build uses upgraded 40-spline shafts or a different ring and pinion configuration, verify the correct locker before purchasing.
FAQ
What GM 14-bolt axles does the ARB RD114 fit?
The RD114 fits compatible GM 14-bolt 10.5" full-floating rear axles with 30-spline axle shafts. It is not designed for the GM 9.5" semi-float 14-bolt, GM 11.5", or 40-spline axle configurations.
Does the ARB RD114 work with 4.56, 4.88, 5.13, or 5.38 gears?
Yes, provided the selected ring and pinion is a compatible thick, high-offset aftermarket gear set designed for the 4.10-and-down carrier configuration. Standard-offset OEM 4.56-and-up ring and pinion sets are not supported. Always verify the specific gear set before installation.
What is the difference between the GM 14-bolt full-float and semi-float axle?
The GM 14-bolt 10.5" full-float axle uses a separate wheel hub and bearing assembly to support vehicle weight, while the axle shafts primarily transfer driving torque. The GM 9.5" semi-float axle uses a different shaft and wheel-end design. These axles require different differential components and are not interchangeable.
Does the RD114 fit factory 30-spline axle shafts?
The RD114 is designed for compatible 30-spline GM 14-bolt full-float axle shafts. Confirm the installed shaft spline count and axle configuration, especially on modified or axle-swapped vehicles.
Does the ARB Air Locker require an air compressor?
Yes. The RD114 requires compressed air to activate the locking mechanism. An ARB air compressor is recommended and sold separately. The locker kit includes the activation switch, solenoid, air line, and bulkhead connection components.
Can I drive on the street with the ARB Air Locker?
Yes. When disengaged, the Air Locker operates as an open differential, allowing the rear wheels to rotate at different speeds during normal turns. Engage the locker when additional traction is needed in appropriate off-road conditions.
Does the RD114 include carrier bearings?
No. The ARB installation manual identifies the carrier bearings as not supplied. Inspect the existing bearings and replace worn components during installation. A compatible differential bearing or master overhaul kit may be required.
Will I need to modify my GM 14-bolt housing?
Possibly. ARB notes that some axle housing castings require clearance modifications. The installation guide specifies a minimum of 2mm clearance between the differential carrier and axle housing casting. Professional installation is recommended.
Is the RD114 a good choice for rock crawling and off-road buggies?
Yes. The GM 14-bolt full-float axle is widely used in heavy-duty off-road builds. The RD114 allows the driver to engage full locking traction for difficult obstacles while retaining open-differential operation when the locker is disengaged. Match the locker and axle shafts to the vehicle's tire size, power, and intended use.
