Fortify your Jeeps drivetrain with Rough Countrys Chromoly Replacement Upgrade Axles! Rough Country 4340 Chromoly axles provide up to 50% increased strength over stock axles for use in extreme performance applications with large tires and high horsepower. Rough Countrys 4340 axles are manufactured using the latest technologies and the highest quality materials to ensure impressive durability and a long lifespan!