Weller is pleased to offer our lineup of Remanufactured DA-RT400-series differentials. Introduced to new trucks in 2017/2018, the RT400 tandem axle differentials offer superior efficiency through the elimination of diff case to Ring gear bolts. These state-of-the-art differentials are fully remanufactured in house with proprietary laser-welding technology. An industry first! Matching the Original Equipment design, Weller Reman DA-RT400 differentials deliver unmatched performance and fuel economy, maximizing your uptime. Offered in ratios 2.16 to 3.23 (3.58 coming late 2026).