Overview PSC Cylinder Assist Steering Kits are engineered to efficiently handle increased torque loads due to the installation of larger-than-stock tire sizes, upgraded aftermarket axles, and/or locking differentials. PSC Cylinder Assist Steering Kits deliver improved handling characteristics without oversteer and a familiar level of road feel without increased driver effort, making it perfect for daily driven, on-the-road use. This component has a SMOOTH DD Input Shaft NOTE For 2008 model vehicles, verify the production date of the vehicle. This can be found on the placard located on the inside of the drivers side B pillar.