GM 4T65-E Transmission Sonnax Oversized Pressure Regulator Valve Kit Symptoms: High line pressure Line pressure instability Lube & converter overheat issues Slide & rotor failure Cause: A worn pressure regulator valve and/or bore. Correction: Improve slide stability and converter/lube control by reaming the bore and installing the oversized aluminum valve. Material: Steel Valve bodies with worn pressure regulator bores can display high and/or unstable line pressure.The Sonnax oversized pressure regulator valve kit 84754-46K and tool kit 84754-TL46 salvages these valve bodies by sizing the bore and freshens the bore surface to improve hydraulic integrity to the pressure regulator oil circuit. Improves slide stability by reducing decrease oil loss Improves balance oil circuit to stabilize the slide Salvages valve body core