August 09, 2018
In GM Gen. 2 6T70/75/80 units, actuator feed limit valve bore wear results in low pressure at the shift and control solenoid valve assembly. The OE valve has a large reaction area and is highly affected by side-loading, which wears the valve body bore. As the bore wear increases, oil pressure is reduced to the shift solenoids, which causes solenoid and ratio codes. This also results in lower line pressure.
Reconditioning the bore and installing Sonnax oversized actuator feed limit valve kit 124740-48K will restore hydraulic control to the shift solenoids.
Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.