42RE/42RH/46RE/46RH/47RE/47RH/48RE/A727/A904 Transmission Sonnax Lube Regulated Pressure Regulator Valve Symptoms: Converter bushing failure Delayed engagement Lube failures Pressure regulator buzz Cause: Poor converter line feed pressure causes delayed engagement, pump bushing and lube failure. Correction: Install this steel valve for improved stability. Lube regulation improves converter feed at low RPM and high throttle conditions. OE valve must match '78-later design. In Chrysler RWD units, the cooler/converter charge circuit is not opened until the pressure regulator valve moves far enough to flow oil. The industry fix of drilling a small orifice between line pressure and cooler circuit ensures fluid to the converter/lube circuit, but the hole also increases the converter drainback problem because ATF can drain out through the orifice when the engine is turned off. Sonnax lube regulated pressure regulator valve 22771A-02K is designed with an internal check valve that allows oil to flow into the converter charge circuit as soon as vehicle is started. Improves converter feed/lube oil flow at critical low RPM and high load conditions. With engine off, check valve prevents fluid from draining out of orifice, reducing converter drainback. WARNING: 22771A-02K and manual valve 22771-09 can be used independently, but are of greatest benefit when used as a pair. NOTE: To prevent converter slippage, restricted cooler flow and possible hydraulic noise, remove the cooler line drainback valve. Valves are designed for all '94-later 42-46-47RE Chrysler units, but can be used in '78-later RH units and A904 and A727 units with TCC