A518, A618, 47RE & 48RE Four Spooled Switch Valve. Replaces the O.E.M. switch valve. Made by TCS for improved timing and flow to the TCC apply and release circuits. Made for performance Dodge diesel applications. Precision CNC machined from billet aluminum. Improves flow for better TCC apply. Prevents TCC shudder. Hardcoat anodized to increase hardness.