4L80E 4L85E Transmission Boost Valve O-Ring Style Sonnax 34200-01K

Manufacturer Part Number: 34200-01KBrand: SonnaxFitment Type: Direct ReplacementManufacturer Warranty: Yes 4L80-E, 4L85-E Boost Valve KitPart No. 34200-01K O-Ring style. Kit can be retrofit to back to '89 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. The Sonnax boost valve kit 34200-01K eliminates these problems. Hardened steel boost valve has over 20% wider spools to provide better durability and increased sealing contact area Boost valve spools have annular grooves to reduce side loading that causes we