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 the Aisin AS69RC utilizes an in-line thermal bypass valve that controls fluid flow 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 a full-flow thermal bypass valve upgrade for your 2019+ RAM 6.7L Cummins.

Our CNC-machined aluminum thermal bypass valve not only looks better than the stock unit, but it performs better too. This Mishimoto thermal bypass valve eliminates the internal thermostat, providing full fluid flow to the transmission cooler in all running conditions. This setup is ideal for owners in warm climates, those performing heavy towing, and trucks needing the best possible cooling efficiency for their transmission. The Mishimoto full-flow thermal bypass valve features strategically machined internal passages, providing improved flow over the stock valve for more effective cooling. In addition, cooling fins machined into the valve body add even more heat dissipation.

This 2019+ RAM 6.7L Cummins Thermal Bypass Full Flow Valve Kit is built to last a lifetime with a durable CNC-machined billet aluminum design and our Mishimoto Lifetime Warranty.

• Equipped with a bypass for uninterrupted cooling in hot weather conditions


• Features a fully serviceable thermostat for rapid warm-up in cold weather


• Helps extend transmission life and prevents overheating

Vehicle Fitment