Product Description
4L60E New Sonnax 77898E-K Reverse Boost Valve And Sleeve Kit 1993 Thru 2004.
This Is A New Never Opened Sonnax Reverse Boost Valve And Sleeve Kit For These Automatic Transmissions;
GMC CHEVY BUICK CADILLAC OLDSMOBILE PONTIAC
4L60E 1993 THRU 2004 (SOME 2005)
This Kit Uses Updated O'rings To Seal Better And Has EPC Spool Valve (Inner Valve) Diameter Of .490" Stock Is .470"
COMPLAINT;
Insufficient line rise
3-4 clutch failure
Poor shift quality
CAUSE;
A worn boost sleeve can allow torque signal and reverse oil cross leakage or leakage to sump
CORRECTION;
This closely tolerance valve and sleeve kit restore hydraulic integrity and prevent leakage.
These kits valves are in .490" increased boost ratio sizes.
SONNAX PRODUCT SUMMARY;
Vehicles with a 4L60-E transmission 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. Oil enters the torque signal orifice, leaks past the boost valve, and exhausts through the reverse orifice, resulting in poor line rise. Reverse oil can exhaust both to the sump and back through the torque signal orifice.
Increased spool diameters (.490" EPC spool diameter), which will result in a higher boost ratio to raise line pressure and provide firmer shifts.
The boost valves have been specially hard coated to eliminate excessive wear from occurring on the inside diameter of the sleeves. These boost sleeves have been manufactured from high quality aluminum, specifically designed to resist wear.
NOTE:
Fits early style units with 1.907" long sleeve OE sleeve only. The 4L60-E, 4L65-E and 4L70-E transmissions will not function properly if the wrong early vs. late design assembly is installed.
THIS VALVE KIT IS 100% SONNAX BUT ORIGINAL SONNAX PACKAGING MAY BE DIFFERENT FROM PICTURE.
