In GM 4L80-E and 4L85-E transmissions, the accumulator control valve controls shift firmness by managing accumulator back pressure. Wear at the valve or bore can lead to multiple symptoms, the most common being reduced line pressure in Reverse, elevated line pressure in Drive, and soft or harsh upshifts depending on location and magnitude of wear. When valve/bore wear allows cross-leakage of torque signal/boost oil to exhaust to the sump, line pressure drops causing soft shifts. Alternatively, when bore wear allows Drive oil to enter the torque signal passage, line pressure increases and shift feel hardens.
Reconditioning the bore and installing Sonnax oversized accumulator control valve kit 34994-22K restores hydraulic integrity of this circuit to re-establish normal shift operation and performance.

Upgrade '91–'96 4L80-E accumulator control valve to '97-later calibration
Restore OE accumulator control valve response in '97-later units

More From This Category

MANLEY Valve, Severe Duty, Exhaust, 1.625 in. Head Dia, 0.3415 in. Stem Dia, 5.465 in. Length, Each

MANLEY Valve, Severe Duty, Exhaust, 1.625 in. Head Dia, 0.3415 in. Stem Dia, 5.465 in. Length, Each

$75.93

MANLEY Valve, Race Master, Intake, 2.02 in. Head Dia, 0.311 in. Stem Dia, 5.728 in. Length, For Dodge, Set of 10

MANLEY Valve, Race Master, Intake, 2.02 in. Head Dia, 0.311 in. Stem Dia, 5.728 in. Length, For Dodge, Set of 10

$500.47

MANLEY Valve, Severe Duty, Exhaust, 1.9 in. Head Dia, 0.311 in. Stem Dia, 5.522 in. Length, For Chevrolet BB, Each

MANLEY Valve, Severe Duty, Exhaust, 1.9 in. Head Dia, 0.311 in. Stem Dia, 5.522 in. Length, For Chevrolet BB, Each

$75.93

MANLEY Valve, Race Flo, Intake, 2.165 in. Head Dia, 0.3133 in. Stem Dia, 5.2 in. Length, For Chevrolet L92, Each

MANLEY Valve, Race Flo, Intake, 2.165 in. Head Dia, 0.3133 in. Stem Dia, 5.2 in. Length, For Chevrolet L92, Each

$51.07

MANLEY Valve, Titanium, Intake, Bead Loc, 2.08 in. Head Dia, 0.311 in. Stem Dia, 5.14 in. Height, Each

MANLEY Valve, Titanium, Intake, Bead Loc, 2.08 in. Head Dia, 0.311 in. Stem Dia, 5.14 in. Height, Each

$320.57

MANLEY Valve, Extreme Duty, Exhaust, 1.88 in. Head Dia, 0.3415 in. Stem Dia, 5.522 in. Length, For Chevrolet BB, Each

MANLEY Valve, Extreme Duty, Exhaust, 1.88 in. Head Dia, 0.3415 in. Stem Dia, 5.522 in. Length, For Chevrolet BB, Each

$129.64