Seattle, August 25th/ ARB 4x4 Accessories/ To meet the voracious demands of the diesel dragsters, sled
pullers and four-wheelers alike, ARB is proud to include this impressively strong new model in their
Performance Air Locker Series. Designed for the 2000-06 GM 2500/3500 models and the 2003 and newer
2500/3500 Dodge Ram, this new 52 pound behemoth is the first of a new breed of heavy torque handling Air
Locking differentials.

ARB’s patented 2-piece case design is manufactured from heavy cross sectioned nodular iron castings for
virtually unbreakable strength and has been designed so that the side gears can be optionally upgraded to 35,
37 and 40 spline shafts. These higher splined side gears will be available in spring 2010.
As with all of ARB’s Performance Lockers, the RD139 features ARB’s patented Timed Gear Technology, which
offers the highest locking strength while maintaining split-second unlocking ability. The steel reinforced, bonded
seal has been designed to handle the most extreme climactic temperatures on earth complementing the
competition bred strength of the locker.

The RD139 is a huge locker that can handle huge power. How much power? Our computer modeling
suggests that this locker will handle upwards of 5 times more torque than the OE differential. We had to
increase the torque load for two reasons - first, to handle the extreme load generated by the extra traction
achieved when this differential is locked, and second, so that ARB could offer future swap-in axle
upgrades to higher torque shafts.
We can honestly say that the RD139 will not be the weak link in your drive train.
The 30 spline, AAM 11.5” Air Locker is available through any ARB retailer by ordering ARB part number
RD139.