Toyota/Lexus vehicles with U140E, U140F, U240E and U241E transmissions may exhibit insufficient line rise in the drive ranges and excessive high pressures in Reverse. This may be caused by continuous oscillation of the steel boost valve within the cast-aluminum sleeve, creating excessive wear and a path for EPC and Reverse pressures to leak. Sonnax boost valve kit 57917E-01K has upgraded materials to prevent wear and to restore proper hydraulic control.

• Boost sleeve manufactured from highly wear-resistant billet aluminum to prevent the excessive wear exhibited by the cast OE sleeve
• Hardcoat anodized aluminum valve combats premature wear
• Restores proper line rise