GM 8L90, 8L45 Remanufactured Valve Bodies 

The 8L90 & 8L45 Valve Bodies Remanufactured with:

The rebuilt valve body’s commonly worn hydraulic circuits that we address:

The GM 8L90 and 8L45 transmissions feature a sophisticated hydraulic system that can experience wear over time in the valve body, leading to performance issues. Key areas of concern include main line pressure, which affects overall system efficiency, and actuator feed limit pressure, which is critical for precise actuator operation. Wear in torque converter apply and release pressures can cause TCC engagement slip or shudder, while issues with clutch control pressure may result in slipping or harsh shifts. Degradation in accumulator signal pressure often leads to inconsistent shift quality. 

8L90/8L45, 2014-18, Part No. 20-160

8L90/8L45, 2019-Up,  Part No. 20-160-19

8L90/8L45, 2016-18, Part No. 20-160SS (Stop/Start)

8L90/8L45, 2019-Up, Part No. 20-160-19SS (Stop/Start)

Note: R&R only. 

Where to Buy 

Shipping Instructions:

Do not send the Pump, Manual Valve, Internal Wiring Harness, or, when equipped, the Stop/Start surge accumulator.

We can not repair broken solenoid connectors.

R&R Shipping Instructions 

Our Unlimited lifetime warranty excludes the 8L90/45, which only comes with a 12-month warranty. 

After Valve Body R&R

NOTE: If the valve body was rebuilt as an R&R, it does NOT require TCM or PUN programming. 


When replacing a GM 8L90 or 8L45 valve body, it is essential to reprogram the Transmission Control Module (TCM) with the valve body's Part Unique Number (PUN). This step ensures proper calibration and optimal shifting performance, as the TCM depends on the PUN to accurately control solenoid flow rates within the valve body. Skipping this process can lead to shifting issues and compromised transmission performance.


General reference:

GM 8L90 Transmission Overview

The GM 8L90 and 8L45 are high-performance, 8-speed automatic transmissions introduced by General Motors in 2014. As the most robust member of GM’s 8LXX family, it is designed for rear-wheel-drive (RWD) applications in luxury and performance vehicles. Key features include:

The 8L90 is a cornerstone of GM's efforts to combine power, efficiency, and reliability in modern vehicles