Sonnax 34200-03K Transmission Boost Valve & Sleeve Kit (Factory Style) 4L80E

Brand: SonnaxOther Part Number: S34507RBKType: Line Pressure BoosterInterchange Part Number: S34507ERKItems Included: Boost Valve KitManufacturer Part Number: 34200-03KUniversal Fitment: YesVintage Part: NoPerformance Part: Yes 4L80-E, 4L85-E Transmission Boost Valve KitPart No. 34200-03K Fits '91-later units with factory-style sleeve, no O-rings. Can be retrofitted to '89–91 units. See instructions for details. Common problems in vehicles with GM 4L80-E and 4L85-E transmissions are uncontrollable line rise (upward of 500-600 psi), high line pressure in Reverse, buzzing noise, broken direct clutch drums and/or broken cases. These problems are usually caused by Reverse boost oil that enters the torque signal circuit due to a wear-created cross leak at the sleeve. High line pressure and buzz is created by oil leakage past the aluminum balance plug. Sonnax boost vavle kit 34200-03K eliminates these problems. Hardened steel boost valve with over 20% wider spools to provide