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.
|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|