Delivering outstanding protection against Chrysler 48RE shaft breakage, Sonnax extreme duty output shaft kit features a unique combination of innovative engineering and quality manufacturing. Stronger materials typically used for improving weak parts can’t overcome the OE shaft’s small, 23-spline cross section. The high-strength alloy balances the toughness required for shaft strength with the deep case hardness required for the one-way clutch race that is an integral part of the shaft. In addition to a materials upgrade, the Sonnax shaft features a significantly larger, 29-spline configuration to protect against breakage that is based on the OE manual transmission spline. For use in 2003-06 4WD models with NV271 or NV273 transfer cases. Requires transfer case disassembly. Not for use in 2WD or earlier 47RE applications with NV241 transfer case.