MTV boost loss and insufficient line rise.
These replacement assemblies prevent oil loss between the outside diameter of the TV sleeve and the pump body.
A common problem in GM 4L60 transmissions is burnt bands and/or 3-4 clutches. This failure can be reduced by eliminating throttle boost oil leakage. Sonnax TV boost valve kit 77917-500 will eliminate these problems for a variety of applications, and will boost pressure higher than TV boost valve kit 77917-471 due to the increased .500" valve spool ratio.
Contact a Sonnax Parts Distributor.