Chrysler 42-46-47-48RH/RE transmissions are equipped with a lockup boost valve that is prone to wear. When this valve wears, it causes a loss of converter and lubrication flow, which can result in TCC slip and an overheated converter. Lockup boost valve wear also causes excessive line pressure, and line rise during TCC apply or in 4th gear can be lost. Sonnax offers an oversized lockup valve boost kit, 22771-19K, that restores the lockup boost circuit pressures. The lockup boost valve kit will correct TCC apply, lubrication and overheat problems, as well as maintain proper line pressure. Both valves are hard-coat anodized aluminum to resist wear The Sonnax spring is calibrated to match OE pressure with the oversized valves Note Fits 90-later with boost oil delivery tube. Contents Lockup Boost Valve Plug Valve Spring Spring Retainer