Locking Traction for Your Workhorse Dana 70.
Whether you are driving a 7.3L Powerstroke Ford F-350, a 5.9L Cummins Ram, or a big-block Chevy 3500, your truck was built to work. However, the factory open or limited-slip differential in your rear Dana 70 often lets you down when traction gets scarce. The ARB RD173 Air Locker is the ultimate traction solution for these classic heavy-duty platforms, giving you the ability to lock your rear axle on demand.
At Overland Truck Store, we recommend this locker for older 1-ton trucks that see mixed use. Unlike automatic lockers that can be harsh on the street or dangerous while towing heavy loads, the ARB Air Locker operates as a standard open differential during normal driving. This preserves your tire life and maintains factory handling characteristics. When you need to pull a heavy trailer out of a muddy field or climb a steep grade, simply flip the switch to instantly lock your 35-spline axle shafts together for 100% traction.
This locker features a robust two-piece case and forged internal gears, designed to handle the torque of big-block gas and diesel engines found in Ford, Dodge, and GM trucks from the 90s and 2000s.
Features & Specs:
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Application:
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Ford: F-350 Super Duty (1999-2016), F-350 OBS (1993-1997), E-350 Vans (1992-2010).
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Dodge: Ram 2500 & 3500 (1994-2002).
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GM: Chevy/GMC C3500 & K3500 (1992-2000), G-Series Vans.
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Axle Fitment: Dana 70 Rear Axle.
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Spline Count: Fits 35 Spline axle shafts.
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Gear Ratio: Designed for 4.10 & Down (numerically lower) ratios (e.g., 3.54, 3.73, 4.10).
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Operation: Pneumatic locking mechanism (Requires on-board air compressor).
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Performance: Provides full spool-like traction when locked, open diff smoothness when unlocked.
Installer Note: This unit is for 35-spline axles with gear ratios of 4.10 and numerically lower. Many of the trucks listed (especially Ford F-350s and Dodge 3500s) may have come with Dana 80 rear axles or different spline counts depending on the year and trim (DRW vs SRW). You must identify your axle tag and verify spline count before ordering to ensure this RD173 is the correct part for your specific build.