To help control the 4th clutch apply pressure and shift feel, a 3-4 accumulator piston and an accumulator valve regulating fluid pressure are used in GM 4T65-E units. The 3-4 accumulator valve regulates line pressure using torque signal influence and directs 3-4 accumulator pressure to the spring side of the piston, controlling the 4th clutch apply. Wear at the bore or valve can allow torque signal, 3-4 accumulator or line pressures to exhaust, resulting in various 3-4 shift complaints.
Reconditioning the bore and installing Sonnax oversized 3-4 accumulator valve kit 84754-55K restores correct hydraulic clearance and shift control in GM units. For Volvo units, Sonnax offers 84754-58K.

Hardcoat anodized valve combats premature wear
Lengthened valve spool for better hydraulic sealing and stability
Annular grooves hydraulically center the valve to reduce wear
To help control the 4th clutch apply pressure and shift feel, a 3-4 accumulator piston and an accumulator valve regulating fluid pressure are used in GM 4T65-E units. The 3-4 accumulator valve regulates line pressure using torque signal influence and directs 3-4 accumulator pressure to the spring side of the piston, controlling the 4th clutch apply. Wear at the bore or valve can allow torque signal, 3-4 accumulator or line pressures to exhaust, resulting in various 3-4 shift complaints.
Reconditioning the bore and installing Sonnax oversized 3-4 accumulator valve kit 84754-55K restores correct hydraulic clearance and shift control in GM units. For Volvo units, Sonnax offers 84754-58K.

Hardcoat anodized valve combats premature wear
Lengthened valve spool for better hydraulic sealing and stability
Annular grooves hydraulically center the valve to reduce wear

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