Valvekit 1-2 Accumulator 4T65 OS
To help control the 2nd clutch apply pressure and shift feel in the 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.
Soft shifts & poor line rise
Wear at the 1-2 accumulator valve and/or bore, allowing loss of torque signal, 1-2 accumulator and/or line pressure.
Refurbish the worn bore and install the Sonnax oversized valve to restore correct hydraulic clearances.
Tool 1-2 Accumultator 4T65 OS: F-84754-TL57
GM General Motors