ARB RD166 Air Locker Differential - Dana 60HD, 35 Spline, 4.56 & Up | 1999-2025 Ford F250/F350

Features:

• Provides 100% traction on demand
• User-friendly operation allows you to concentrate on the terrain
• Two-piece design is ultra-durable
• Timed locking mechanism
• Steel reinforced design
• Includes all necessary hardware and instructions
• Air compressor required for operation (sold separately)

Locking Differential for Higher Gear Ratios

The ARB Air Locker Differential for the 1999-2025 Ford F250/F350 Dana 60HD axle is designed for drivers who need maximum traction and control in extreme off-road conditions. This Air Locker is built for vehicles running a 35-spline axle shaft and is specifically compatible with gear ratios of 4.56 and higher, making it ideal for trucks set up for off-roading or heavy towing. Higher gear ratios are often chosen by those who need more torque for climbing steep inclines or navigating challenging trails, and the RD166 is engineered to handle these demanding scenarios. With a simple flip of a switch, this differential instantly locks both wheels together, giving you 100% traction when you need it most. This feature makes it far superior to stock open differentials, which allow one wheel to spin uselessly when traction is lost.

Ultra-Durable Design

Another major benefit of the ARB Air Locker is its ultra-durable, two-piece design. This reduces the number of moving parts, enhancing the unit’s reliability and ensuring that it holds up under extreme stress. The patented timed locking mechanism provides not only high strength but also fast unlocking, allowing for instant transition between full lock and open differential, so you get back to regular on-road driving quickly and smoothly. Additionally, the elastomer-bonded annular seal is reinforced with steel, making it capable of handling the most extreme climates and conditions, whether you're driving through intense heat, freezing temperatures, or muddy, water-filled trails. Just like the RD167, this kit includes everything you need for installation, except the air compressor (sold separately), which powers the pneumatic system. ARB ensures that installation and operation is straightforward and reliable, allowing you to focus on driving and navigating the terrain ahead without worrying about your differential.

Fits: 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025 Ford F250/F350 Super Duty w/ Dana 60HD

Notes:

• Fits 1999–2025 Ford F-250 and F-350 with Dana 60HD axles
• Compatible only with 35-spline axle shafts
• Designed for gear ratios of 4.56 and higher
• Ideal for off-road and heavy towing applications
• Provides 100% traction on demand when activated
• Requires an air compressor for operation (sold separately)
• Compatible with ARB compressors CKSA12, CKMA12, or CKMTA12
• Two-piece design improves strength and reliability
• Timed locking mechanism allows rapid lock and unlock
• Steel-reinforced annular seal handles extreme conditions
• Includes installation hardware and detailed instructions
• Verify axle spline count and gear setup before ordering

Install Instructions