A common problem in GM 200-4R and 4L60 transmissions is burned bands and/or 3-4 clutches. This failure can be reduced by eliminating throttle boost oil leakage. The Sonnax TV boost valve kits [77917-01K] (.423" dia.), 77917-471 (.471" dia.) and 77917-500 (500" dia.) eliminate these problems for a variety of applications. For higher line pressure for towing and off-road, use Sonnax TV boost valve kit 77917-471.

Throttle valve boost valve and sleeve are made from made from hardened steel for better wear resistance
O-Rings on sleeve separate throttle pressure and Reverse boost circuits, providing additional protection against cross-leaks
O-Rings prevent loss of oil between the outside diameter of the throttle valve sleeve and pump body
Drop-in Zip Valve™ parts install quickly and easily


Sonnax Part No.
Sleeve Dia.
Performance Application


[77917-01K]
.423" dia.
Minimum line pressure for V8 applications

77917-471
.471" dia.
Higher line pressure for towing and off-road

77917-500
.500" dia
Maximum line pressure & shift feel for high performance applications


Learn More About Zip Valve™ Drop-In Repairs

More From This Category

Sonnax Tcc Regulator Valve, Ford, 4R44E/4R55E, 5R44E/5R55E, Each

Sonnax Tcc Regulator Valve, Ford, 4R44E/4R55E, 5R44E/5R55E, Each

$29.02

COMP Cams Valve, Sportsman, Stainless Steel, Intake, GM LS7, 2.200 in. Head, 5.550 in. Length, Set of 8

COMP Cams Valve, Sportsman, Stainless Steel, Intake, GM LS7, 2.200 in. Head, 5.550 in. Length, Set of 8

$1,910.22

MANLEY Valve, Severe Duty, Intake, 2.3 in. Head Dia, 0.3415 in. Stem Dia, 5.494 in. Length, Each

MANLEY Valve, Severe Duty, Intake, 2.3 in. Head Dia, 0.3415 in. Stem Dia, 5.494 in. Length, Each

$79.73

MANLEY Valve, Titanium, Intake, Bead Loc, 2.3 in. Head Dia, 0.3415 in. Stem Dia, 5.5 in. Length, Set of 8

MANLEY Valve, Titanium, Intake, Bead Loc, 2.3 in. Head Dia, 0.3415 in. Stem Dia, 5.5 in. Length, Set of 8

$2,678.30

MANLEY Valve, Titanium, Intake, 2.25 in. Head Dia, 0.3415 in. Stem Dia, 5.25 in. Length, Set of 8

MANLEY Valve, Titanium, Intake, 2.25 in. Head Dia, 0.3415 in. Stem Dia, 5.25 in. Length, Set of 8

$2,678.30

MANLEY Valve, Titanium, Exhaust, Bead Loc, 1.6 in. Head Dia, 0.3415 in. Stem Dia, 5.14 in. Height, Set of 8

MANLEY Valve, Titanium, Exhaust, Bead Loc, 1.6 in. Head Dia, 0.3415 in. Stem Dia, 5.14 in. Height, Set of 8

$2,584.74