4L80E TransGo Valve Body Shift Kit, 1991-2013, SK 4L80E.
This TransGo 4L80E SHIFT KIT® Valve Body Repair Kit fits 1991-2013 GM vehicles equipped with the 4L80E and 4L85E automatic transmission. Common complaints on this transmission include soft 2-3, no upshifts, burnt direct clutch, broken hard parts due to high pressure, low pressure due to solenoid filter breakup as well as gear ratio and solenoid performance codes.
The boost valve assembly is 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.
This 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. Also, 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.