November 03, 2022
Wear in the main pressure regulator bore and on the outboard spool area of the valve is common in listed GM and Ford 10-speed transmissions. This wear minimizes line pressure control resulting in delayed shift engagement, poor shift quality and burnt clutches. Wear at the inboard spool and bore can lead to converter apply issues.
Installing the drop-in Sonnax main pressure regulator valve kit 105740-12K eliminates the leakage of line pressure signal oil to exhaust with the incorporation of an extended front valve spool. This valve spool is 270% longer than the OE spool, so actuates in unworn areas of the bore. The O-ringed end plug provides a positive seal and prevents critical signal fluid from leaking to exhaust. Both of these Sonnax features ensure your units will have proper line pressure control through all drive ranges.
Learn More About Zip Valve™ Drop-In Repairs
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.