November 14, 2016
Vehicles with 4R70W and AODE transmissions often have erratic line pressure, poor line rise and/or throttle-sensitive buzz. This can result in harsh or soft shifts and band/clutch failure as well as other driveability concerns. Worn pressure regulator valve spools allowing pressure escape are a common problem in these units. Installing Sonnax main pressure regulator valve 76948-01 restores normal line pressure operation in all ranges.
If bore is excessively worn, install Sonnax oversized pressure regulator and boost valve kit 76948-16K.
'91–'95 PR valve and '96-later PR valve designs are not interchangeable. For '96-later PR valve, see 76948-09.
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.