The transmission is the backbone of your RAM. It's responsible for transmitting large amounts of torque from your 6.7L Cummins powerplant, and that torque generates heat. If that heat isn't dissipated, it can destroy your transmission. The transmission cooler does a good job of keeping trans fluid temperatures in check, but only if the fluid can reach it. The stock cooling system of both the 68-RFE and Aisin AS69RC utilize an in-line thermal bypass valve that controls the flow of fluid to the transmission cooler. The purpose of this valve is to prevent transmission fluid from flowing to the cooler until it reaches operating temperature. The thermostat inside this valve is prone to failure, however, and when that happens, the fluid never flows to the cooler and the transmission can overheat. That's why Mishimoto has developed an improved thermal bypass valve kit for your 2019+ Dodge Ram 6.7L Cummins. Our CNC-machined aluminum thermal bypass valve not only looks better than the stock unit, but it performs better too. The Mishimoto thermal bypass valve utilizes a replaceable thermostat that is more durable than the stock thermostat and opens about 10 F earlier. This allows fluid to flow to the cooler sooner, without over-cooling. For owners in hot climates, the Mishimoto valve includes a bypass that allows full flow to the transmission cooler, regardless of temperature. The bypass can be easily swapped out with only a wrench for summer or winter driving. The Mishimoto thermal bypass valve flows better in both configurations than the stock valve for more effective cooling. Cooling fins machined into the valve body add even more heat dissipation. This 2019+ Dodge Ram 6.7L Cummins Thermal Bypass Valve Kit is built to last a lifetime with a durable black anodized finish and our Mishimoto Lifetime Guarantee.