Transmissions listed above may exhibit insufficient line rise, resulting in delayed engagement, slipping in Reverse, poor shift quality, erratic line pressure and burnt clutches. These troubles can often be caused by wear in the OE pressure regulator valve bore and/or boost sleeve, which allows the pressure escape that provokes driveability concerns. Reconditioning the bore and installing Sonnax oversized pressure regulator and boost valve kit 63741-01K eliminates pressure loss and revives line rise and shift quality in all ranges. Hardcoat anodized aluminum pressure regulator valve combats premature wear.