Sonnax 77917-07 Oversized Pressure Regulator Valve for GM Transmissions - 4L60-E 4L65-E 4L70-E

The Sonnax 77917-07 is an oversized pressure regulator valve designed to address pressure regulator leakage in GM 4L60-E, 4L65-E and 4L70-E automatic transmission pump bodies. This precision-engineered valve restores proper pressure control and eliminates common performance issues caused by worn original equipment components.

Key Features:

• Permits pump covers to be restored to OE specifications by correcting for wear and leakage at the pressure regulator valve
• Oversized design compensates for bore wear in high-mileage transmission pumps
• Helps restore control over the pressure regulating circuit by eliminating leakage
• Requires reaming the bore prior to installation (reaming tool sold separately)

Addresses Common Problems:

• Low line pressure during boost conditions (50-100 psi less than specified in Reverse), clutch slippage, reverse chatter and 3-4 clutch failure
• Erratic pump performance and excessive noise
• Uncontrollable line pressure fluctuations

This oversized pressure regulator valve is a professional-grade solution for transmission rebuilders and experienced technicians performing pump body refurbishment. When oversizing the pressure regulator valve, it is recommended to move up one boost ratio and check boost valves for leakage during installation.