Oversize S4 Regulator Valve
Fits 2018-on 8L45, 8L90 late 2-land S4 valve
Requires 8L90-S4LATE-TK
- Distributor Part Numbers
- Documents
- General Details
New oversize S4 regulator valve for GM 8L45 and 8L90 solves 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 redesigned this 2-land style S4 valve with an oversize hardened steel valve, lengthening the land on the spring side to ride in an unworn portion of the bore, restoring 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
Requires #8L90-S4LATE-TK tool kit