The transmission is the backbone of your Grand Cherokee. It's responsible for transmitting large quantities of torque from your V8 or 3.0L EcoDiesel powerplant. That much torque generates a lot of heat, and 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 8HP transmission 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 2016-2020 Jeep Grand Cherokee. The Mishimoto thermal bypass valve kit includes an all-aluminum CNC-machined housing that replaces the stock unit. This full-flow valve allows fluid to pump through the cooler as soon as the vehicle is started, eliminating the potential failure point of the stock bypass and providing cooling benefits. The full-flow design is beneficial to vehicles operating in hot climates, extreme driving conditions, or towing heavy loads. As with Mishimoto products, this Full-Flow Transmission Thermal Bypass Valve Kit includes our signature Lifetime Warranty.