Toyota/Lexus vehicles equipped with U341E and U341F transmissions may exhibit insufficient line rise, resulting in delayed engagement, slipping in Reverse, poor shift quality and burnt clutches. These troubles can often be caused by wear in the OE pressure regulator valve bore and/or boost sleeve, which allows pressure escape that causes driveability concerns. Reconditioning the bore and installing Sonnax oversized pressure regulator and boost valve kit 37740-03K eliminates pressure loss and revives line rise and shift quality in all ranges.
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.