Transmission kit 4L80E, 4L85E, 91-08. General Motors by Transgo

This TransGo 4L80E SHIFT KIT Valve Body Repair Kit fits 1991 to 2013 General Motors vehicles equipped with the 4L80E and 4L85E automatic transmission. Common complaints on the 4L80E and 4L85E automatic transmissions are soft 2-3 shifts, no upshifts, burnt direct clutch, broken hard parts (due to high pressure), and low pressure (due to solenoid filter breakup as well as gear ratio and solenoid performance codes). The boost valve assembly in these transmissions are notorious for wear causing both low pressure as well as runaway boost pressure. With the low boost problem results in complaints of soft 2-3, direct clutch failure as well as the gear ratio and solenoid performance codes. On the other hand, the runaway boost pressure problem results in costly broken case, direct drum and piston. Features and benefits: The TransGo 4L80E SHIFT KIT Valve Body Repair Kit includes valve body, case and pump components and modifications designed to deliver increased durability while providing short smooth shifts. These changes work in concert with a slight increase in line pressure to greatly improve the overall durability and shift feel of the transmission. The included highly improved wide land self-cleaning design boost valve and bushing resists wear so that pressure rise keeps working properly. Lastly, the EPC boost pressure relief valve system provided helps prevent runaway boost pressure to stop case and valve body wall blow-out due to excess pressure. Corrects/Prevents/Reduces: High pressure parts breakage Soft 2-3 shift Burnt direct clutch Slow 3-2 downshift No upshifts Harsh 1-2 shift Low pressure due to solenoid filter breakup Codes 39, 68, 85, 86, 87, P0731, P0732, P0733, P0734, P0751, P0756, P0894 and P1870 Includes: USA-made hardened boost valve and bushing Pressure regulator valve spacer, washer, springs and snap ring New stronger 4th feed bolt and washer (2) Direct and reverse feed hole cup seals Relief valve system plate, valve, spring, e-clip and drill bit (2) Accumulator valve springs, end plug and O-ring Actuator filter tapered plug, O-ring, spring and end plug