To help control the 2nd clutch apply pressure and shift feel in the GM 4T65-E, a 1-2 accumulator piston and accumulator valve regulating fluid pressure are used. The 1-2 accumulator valve regulates line pressure using torque signal influence and directs 1-2 accumulator pressure to the spring side of the piston, controlling the 2nd clutch apply. Wear at the bore or valve can allow torque signal, 1-2 accumulator or line pressures to exhaust, resulting in various 1-2 shift complaints.
Sonnax oversized 1-2 accumulator valve 84754-57K is made from wear-resistant, hard-coat anodized aluminum to prevent future wear in a refurbished bore. Annular grooves have been added to the valve spool to hydraulically center the valve in the bore for wear resistance.
Valve is hard-coat anodized to prevent wear
Can be used in either early- or late-style valve bodies
Annular grooves added for hydraulic centering and wear reduction