Description: 4L60-E, 4L65-E, 4L70-E Transmission Boost Valve Kit Part No. 77898E-16K Late pump design, .472" dia., O-ring style with OE ratio GM 4L60-E, 4L65-E and 4L70-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-16K is a large OE ratio assembly that will restore hydraulic integrity and prevent leakage in units with late-design pumps. Drop-in Zip Valve™ parts install quickly and easily. See chart below for usage details and other boost valve options.Contents Valve 4 Grooves, .472" dia. Sleeve O-Rings (3) 1 Extra Symptoms: 3-4 Clutch failure2-4 Band failureLow line risePoor shift qualityCause: A worn boost sleeve can allow torque signal and Reverse oil cross-leakage or leakage to sump. Correction: Sonnax drop-in boost valve kit restores hydraulic integrity and prevents leakage.
Price: 39.9 USD
Location: Columbus, Ohio
End Time: 2024-12-27T19:37:24.000Z
Shipping Cost: N/A USD
Product Images
Item Specifics
Return shipping will be paid by: Seller
Returns Accepted: Returns Accepted
Item must be returned within: 30 Days
Refund will be given as: Money back or replacement (buyer's choice)
Return policy details:
OE Spec or Performance/Custom: Performance/Custom
Brand: Sonnax
Interchange Part Number: S74507THK
Manufacturer Warranty: No Warranty
Items Included: Line Pressure Boost Valve Kit
Manufacturer Part Number: 77898E-16K
Country/Region of Manufacture: United States
Universal Fitment: Yes
Vintage Part: No
Performance Part: Yes
