The Allison transmission serves as the backbone of your L5P Duramax.
It is responsible for transmitting large quantities of torque from your V8 diesel powerplant.
This torque generates a significant amount of heat, and if that heat is not dissipated, it can destroy your transmission.
The transmission cooler effectively keeps trans fluid temperatures in check, but only if the fluid can reach it.
The stock cooling system of the Allison 1000 transmission uses an in-line thermal bypass valve that controls fluid flow to the transmission cooler.
The valve's purpose is to prevent transmission fluid from flowing to the cooler until it reaches operating temperature.
However, the thermostat inside this valve is prone to failure, and when that occurs, the fluid never flows to the cooler, leading to transmission overheating.
That is why Mishimoto has developed a thermal bypass valve upgrade for your 2017+ Chevrolet/GMC 6.6L Duramax.
Our CNC-machined aluminum thermal bypass valve not only looks better than the stock unit, but it also performs better.
This Mishimoto thermal bypass valve kit includes a fully serviceable thermostat for fast warm-up in cold climates.
Additionally, this kit includes a thermostat bypass that can be installed to provide constant cooling in warm climates or for use in extreme driving/towing conditions.
The Mishimoto thermal bypass valve features strategically machined internal passages, which provide improved flow over the stock valve for more effective cooling.
Furthermore, cooling fins machined into the valve body add even more heat dissipation.
This 2017+ Chevrolet/GMC 6.6L Duramax L5P Thermal Bypass Valve Kit is built to last a lifetime with a durable black anodized finish.