4L80E 4L85E Transmission Updated Boost Valve Sonnax 34200-03K 1991 Up

4L80E 4L85E Transmission Boost Valve Factory Style Sonnax 34200-03K 1991 UpCommon problems in vehicles with a 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 vavle kit 34200-03K eliminates these problems.Hardened steel boost valve with 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 wear.Valve and sleeve are manufactured to close tolerances to restore proper clearance and hydraulic integrity.Kit includes a replacement aluminum balance oil plug with an O-ring to ensure proper sealing and adequate back pressure on the pressure regulator valve.NoteIf you detect leakage between the sleeve and pump bore, use 34200-01K, which includes an O-ringed sleeve to compensate for pump bore wear and prevent pump scrappage.ContentsBalance Plug with O-RingBoost Sleeve Factory style, no O-ringsBoost ValveAPPLICATIONS Hummer H1 1993-2005 V8 Gas 6.5L Diesel 4 Spd RWD 4X4Escalade, ESV, EXT 2006-2007 V8 4.8L 5.3L 4 Spd RWD AWDAvalanche 2001-2003 V8 8.1L 4 Spd RWD 4X4Express, Savana, 2500-3500 1996-2009 V8 4.8L 5.3L 5.7L 4 Spd RWD 4X4Express, Savana, 2500-3500 1996-2009 V8 6.0L 7.4L 4 Spd RWD 4X4Express, Savana, 2500-3500 2006-2010 V8 6.6L Diesel 4 Spd RWD 4X4Express, Savana, 3500 2002 V8 8.1L 4 Spd RWD 4X4Silverado,Sierra,1500-3500 1995-2007 V8 5.0L 5.7L 6.0L 6.5L 4 Spd RWD 4X4Silverado,Sierra,1500-3500 1995-2007 V8 6.6L Diesel 4 Spd RWD 4X4Suburban 1500-2500 1995-2007 V8 5.7L 6.0L 4 Spd RWD 4X4Suburban 1500-2500 1995-2007 V8 6.5L Diesel 4 Spd RWD 4X4Tahoe, Yukon 1995-2007 V8 5.7L 6.0L 4 Spd RWD 4x4Tahoe, Yukon 1995-2007 V8 6.5L Diesel 4 Spd RWD 4X4NPR Truck 1991-2004 V8 5.7L 4 Spd RWDNPR Truck 2005-2010 V8 6.0L Gas 4 Spd RWDXJS 1993-1996 L6 4.0L; V12 6.0L 4 Spd RWD    Please be sure your Pan has 17 Bolt Holes for your Transmission to be a 4L80E  Parts ship daily from our distribution center.FREE SHIPPING on US Orders GOT QUESTIONS on your specific Year/Make/Model? Send us a message ¿Habla español? Escríbanos con el año, la marca, y el modelo de su vehículo. This item is packaged for Wholesale Distribution WARRANTY requests need to be accompanied with the appropriate codeas diagnosed by a professional transmission shop.Vehicles must be professionally diagnosed for solenoid failure prior to purchase.We cannot guarantee any one item will fix all transmission problems.Solenoid failure is often accompanied by additional failures;for example valve body failures, internal wear or damaged hard parts Visit our eBay Store: Phoenix Transmission Parts  For all of your Automatic Transmission Part needsCheck out my other items!Be sure to add me to your favorites list!