Sonnax 77917-500 TV Boost Valve Kit .500" O-Ring Style GM 200-4R 700R4 4L60

The Sonnax 77917-500 TV boost valve kit is a high-performance upgrade designed to eliminate common transmission failures in GM 200-4R, 700R4, and 4L60 automatic transmissions. This drop-in kit addresses the widespread problem of burned bands and 3-4 clutches caused by throttle boost oil leakage, providing a reliable solution for both stock and performance applications.

Key Features:

• 0.500" diameter valve spool for maximum pressure boost and performance applications
• Hardened steel construction on both valve and sleeve for superior wear resistance
• O-ring sealed sleeve design prevents oil leakage between throttle valve sleeve and pump body
• O-rings separate throttle pressure and reverse boost circuits, eliminating cross-leak issues
• Returns higher line pressure than OE-ratio valves for improved shift firmness and clutch holding power
• Drop-in Zip Valve design installs quickly without extensive disassembly

This kit includes the boost valve, sleeve, and two O-rings. The .500" diameter valve provides the highest pressure increase of Sonnax's TV boost valve lineup, making it ideal for high-performance and heavy-duty applications where maximum transmission holding power is required. The larger valve spool ratio delivers progressive pressure increases that respond to throttle position, improving shift quality and extending transmission life.