77898E-6K sonnax 4L60E, 4L65E Boost Valve Kit .470" 1 groove

Brand: sonnaxType: Pump ComponentManufacturer Warranty: YesItems Included: Boost valve and sleeveManufacturer Part Number: 77898E-6KUniversal Fitment: YesPerformance Part: No 4L60-E, 4L65-E Transmission Boost Valve KitPart No. 77898E-6K Early pump design, .470" dia., factory style, no O-rings with OE ratio GM 4L60-E and 4L65-E transmissions frequently have poor line rise, which can result in 3-4 clutch, 2-4 band failure or poor shift quality. The duty cycle of the EPC solenoid causes the boost sleeve to wear quickly. Oil entering the torque signal orifice leaks past the boost valve and exhausts at the Reverse orifice, resulting in poor line rise. Reverse oil can exhaust both to the sump and back through the torque signal orifice. The outside diameter of the boost sleeve also allows some leakage through the pump body, which decreases pressure rise. Sonnax boost valve kit 77898E-6K is a large OE ratio assembly that will restore hydraulic i