Upgrades

6L80 6L90 8L90 Cooler Bypass Eliminator Kit | Sonnax

Services Two Vehicles The OE thermal bypass element in GM 6L80, 6L90 and 8L90 transmissions is prone to sticking open or closed, restricting cooler flow and leading to transmission overheating and damage. Sonnax cooler bypass eliminator kit...

8L90 8L45 Oversized S4 Regulator Valve (2018-UP) Late 2-Land S4 Valve

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...

8L90 8L45 Drop-In Replacement PR Shuttle Valve Assembly

This pressure regulator (PR)/shuttle valve assembly is an easy, drop-in solution for a common wear location on 8L45 and 8L90 automatic transmissions. Corrects/Prevents/Reduces: High line pressure Unstable line pressure Broken parts Loss of converter...