TransGo Oversized S4 Regulator Valves

TransGo's new oversized S4 regulator valves GM 8L45 and 8L90 solve significant wear issues at the S4 regulator valve position. When General Motors made a change to the S4 regulator valve in both the 8L45 and 8L90 transmissions, the updated 2-land design and computer command strategy resulted in significant increased wear, even at low mileage. TransGo Performance redesigned this 2-land style S4 valve with an oversize hardened steel valve, lengthening the land on the spring side to restore hydraulic integrity of the circuit and sealing the signal oil side with a PTFE ring to ensure longevity.

* Corrects/Prevents/Reduces:
-- Slip 1-2 or 1-3 shift
-- Harsh 1-2 or 1-3 shift
-- Coast downshift clunks
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