Vehicles with GM 5L40-E and 5L50-E transmissions are prone to poor line rise or high Reverse pressure problems causing poor shift quality and clutch failure due to leakage at the boost valve assembly. Sonnax offers two boost valve kits: the 55209-01K performance ratio (higher line rise and firmer shifts) and the OE ratio 55209-04K for factory performance.

Hardcoat anodized aluminum valves combat premature wear
Boost sleeves are made from alloy aluminum specifically designed to resist wear
Increased performance ratio 55209-01K or OE ratio 55209-04K assemblies are available
Drop-in Zip Valve™ parts install quickly and easily

Learn More About Zip Valve™ Drop-In Repairs

More From This Category

Sonnax Oversized Torque Converter Lube Regulator & Plunger Valve Kit, JF015E (Reof11A), Each

Sonnax Oversized Torque Converter Lube Regulator & Plunger Valve Kit, JF015E (Reof11A), Each

$89.18

Sonnax Oversized Pressure Regulator Valve, ZF5Hp19, Early Vb E17, Each

Sonnax Oversized Pressure Regulator Valve, ZF5Hp19, Early Vb E17, Each

$65.05

MANLEY Valve, Race Flo, Intake, 32.0 mm Head Dia, 6 mm Stem Dia, 99.60 mm Length, Set of 8

MANLEY Valve, Race Flo, Intake, 32.0 mm Head Dia, 6 mm Stem Dia, 99.60 mm Length, Set of 8

$399.33

MANLEY Valve, Race Flo, Intake, 2.1 in. Head Dia, 0.3133 in. Stem Dia, Hollow Stem, 4.874 in. Length, For Chevrolet LS1, Set of 8

MANLEY Valve, Race Flo, Intake, 2.1 in. Head Dia, 0.3133 in. Stem Dia, Hollow Stem, 4.874 in. Length, For Chevrolet LS1, Set of 8

$1,138.39

MANLEY Valve, Titanium, Exhaust, Bead Loc, 1.625 in. Head Dia, 0.3415 in. Stem Dia, 5.64 in. Height, Set of 8

MANLEY Valve, Titanium, Exhaust, Bead Loc, 1.625 in. Head Dia, 0.3415 in. Stem Dia, 5.64 in. Height, Set of 8

$2,461.66

MANLEY Valve, Titanium, Intake, Bead Loc, 2.5 in. Head Dia, 0.3415 in. Stem Dia, 6.4 in. Length, Set of 8

MANLEY Valve, Titanium, Intake, Bead Loc, 2.5 in. Head Dia, 0.3415 in. Stem Dia, 6.4 in. Length, Set of 8

$2,591.35