Common problems in vehicles with a 4L80-E transmission include uncontrollable line rise (upward of 500 psi), high line pressure in reverse, broken direct clutch drums and/or broken cases. These problems can be caused by excessive EPC torque signal pressure. The Sonnax self-regulating reverse boost valve 34200-10K eliminates these problems by limiting EPC pressure.
- Hardened steel boost valve has an encapsulated relief valve that will allow EPC pressure to exhaust if it exceeds 95-105 psi.
- 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.
- Closely toleranced sleeve restores the hydraulic integrity between the valve and sleeve.
- O-rings have been added to the sleeve to provide a positive seal that compensates for pump bore wear.
Kit includes instructions to retrofit parts dating back to 89.
- Valve
- Sleeve
- O-Rings (2)
APPLICATIONS
Hummer H1 1993-2005 V8 Gas 6.5L Diesel 4 Spd RWD 4X4
Escalade, ESV, EXT 2006-2007 V8 4.8L 5.3L 4 Spd RWD AWD
Avalanche 2001-2003 V8 8.1L 4 Spd RWD 4X4
Express, Savana, 2500-3500 1996-2009 V8 4.8L 5.3L 5.7L 4 Spd RWD 4X4
Express, Savana, 2500-3500 1996-2009 V8 6.0L 7.4L 4 Spd RWD 4X4
Express, Savana, 2500-3500 2006-2010 V8 6.6L Diesel 4 Spd RWD 4X4
Express, Savana, 3500 2002 V8 8.1L 4 Spd RWD 4X4
Silverado,Sierra,1500-3500 1995-2007 V8 5.0L 5.7L 6.0L 6.5L 4 Spd RWD 4X4
Silverado,Sierra,1500-3500 1995-2007 V8 6.6L Diesel 4 Spd RWD 4X4
Suburban 1500-2500 1995-2007 V8 5.7L 6.0L 4 Spd RWD 4X4
Suburban 1500-2500 1995-2007 V8 6.5L Diesel 4 Spd RWD 4X4
Tahoe, Yukon 1995-2007 V8 5.7L 6.0L 4 Spd RWD 4x4
Tahoe, Yukon 1995-2007 V8 6.5L Diesel 4 Spd RWD 4X4
NPR Truck 1991-2004 V8 5.7L 4 Spd RWD
NPR Truck 2005-2010 V8 6.0L Gas 4 Spd RWD
XJS 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.
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