Mishimoto 2017+ GMC 6.6L Duramax L5P Transmission Thermal Bypass Valve Kit

The Allison transmission is the backbone of your L5P Duramax. It's responsible for transmitting large quantities of torque from your V8 diesel powerplant. This 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 Allison 1000 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 2017-2019 Chevrolet/GMC 6.6L Duramax. Our CNC-machined aluminum full-flow 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 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 adds even more heat dissipation. This 2017-2019 Chevrolet/GMC 6.6L Duramax L5P Full-Flow Thermal Bypass Valve Kit is built to last a lifetime with a durable black anodized finish and our Mishimoto Lifetime Warranty. Automatic transmission oil cooler designed to regulate fluid temperature and prevent overheating. Enhances transmission longevity, maintains performance, and features durable construction with a precise fit.

• Durable CNC-machined billet-aluminum construction
• Eliminates failure-prone bypass valve
• Installs in less than 1 hour

The Mishimoto Full-Flow Thermal Bypass Valve Kit is designed specifically for your 2017-2019 Chevrolet Silverado and GMC Sierra 2500HD/3500HD with the Duramax L5P engine. This high-quality CNC-machined billet aluminum upgrade replaces the stock thermostat-controlled bypass valve, ensuring consistent fluid flow to the transmission cooler under all operating conditions. Proper cooling of your transmission fluid is essential for maintaining optimal performance, preventing overheating, and extending the lifespan of your transmission, especially when towing heavy loads or operating in warm climates. The Mishimoto bypass valve features strategically machined internal passages that improve flow compared to the stock unit, along with cooling fins integrated into the valve body to enhance heat dissipation. Its durable black anodized finish guarantees long-lasting corrosion resistance and a professional appearance. Installation is straightforward and can typically be completed in less than an hour, making this an accessible upgrade for DIY enthusiasts and professionals alike. By eliminating the internal thermostat, this full-flow valve ensures your transmission fluid reaches the cooler efficiently at all times, which is crucial for high-demand driving conditions. The kit's precise fit and robust construction provide peace of mind, knowing your transmission will operate at safer temperatures, reducing wear and promoting vehicle longevity. Whether you regularly tow heavy loads, drive in hot environments, or simply want the best cooling performance, this Mishimoto thermal bypass valve offers a reliable and effective solution to keep your Duramax L5P transmission running smoothly. Backed by Mishimoto’s lifetime warranty, this upgrade is designed to serve your vehicle for years to come, providing consistent performance and peace of mind during demanding drives.

Features:

• Durable CNC-machined billet-aluminum construction ensures long-lasting performance

• Eliminates failure-prone internal thermostat for consistent fluid flow

• Improves transmission cooling efficiency with strategically machined internal passages

• Includes cooling fins for enhanced heat dissipation

• Easy installation, typically completed in less than 1 hour

• Black anodized finish for corrosion resistance and aesthetic appeal

Fitment:
2017 Chevrolet Silverado 2500 HD High Country
2017 Chevrolet Silverado 2500 HD LT
2017 Chevrolet Silverado 2500 HD LTZ
2017 Chevrolet Silverado 2500 HD WT
2017 Chevrolet Silverado 3500 HD High Country
2017 Chevrolet Silverado 3500 HD LT
2017 Chevrolet Silverado 3500 HD LTZ
2017 Chevrolet Silverado 3500 HD WT
2017 GMC Sierra 2500 HD Base
2017 GMC Sierra 2500 HD Denali
2017 GMC Sierra 2500 HD SLE
2017 GMC Sierra 2500 HD SLT
2017 GMC Sierra 3500 HD Base
2017 GMC Sierra 3500 HD Denali
2017 GMC Sierra 3500 HD SLE
2017 GMC Sierra 3500 HD SLT
2018 Chevrolet Silverado 2500 HD High Country
2018 Chevrolet Silverado 2500 HD LT
2018 Chevrolet Silverado 2500 HD LTZ
2018 Chevrolet Silverado 2500 HD WT
2018 Chevrolet Silverado 3500 HD High Country
2018 Chevrolet Silverado 3500 HD LT
2018 Chevrolet Silverado 3500 HD LTZ
2018 Chevrolet Silverado 3500 HD WT
2018 GMC Sierra 2500 HD Base
2018 GMC Sierra 2500 HD Denali
2018 GMC Sierra 2500 HD SLE
2018 GMC Sierra 2500 HD SLT
2018 GMC Sierra 3500 HD Base
2018 GMC Sierra 3500 HD Denali
2018 GMC Sierra 3500 HD SLE
2018 GMC Sierra 3500 HD SLT
2019 Chevrolet Silverado 2500 HD High Country
2019 Chevrolet Silverado 2500 HD LT
2019 Chevrolet Silverado 2500 HD LTZ
2019 Chevrolet Silverado 2500 HD WT
2019 Chevrolet Silverado 3500 HD High Country
2019 Chevrolet Silverado 3500 HD LT
2019 Chevrolet Silverado 3500 HD LTZ
2019 Chevrolet Silverado 3500 HD WT
2019 GMC Sierra 2500 HD Base
2019 GMC Sierra 2500 HD Denali
2019 GMC Sierra 2500 HD SLE
2019 GMC Sierra 2500 HD SLT
2019 GMC Sierra 3500 HD Base
2019 GMC Sierra 3500 HD Denali
2019 GMC Sierra 3500 HD SLE
2019 GMC Sierra 3500 HD SLT
2020 Chevrolet Silverado 2500 HD High Country
2020 Chevrolet Silverado 2500 HD LT
2020 Chevrolet Silverado 2500 HD LTZ
2020 Chevrolet Silverado 2500 HD WT
2020 Chevrolet Silverado 3500 HD High Country
2020 Chevrolet Silverado 3500 HD LT
2020 Chevrolet Silverado 3500 HD LTZ
2020 Chevrolet Silverado 3500 HD WT
2020 GMC Sierra 2500 HD AT4
2020 GMC Sierra 2500 HD Base
2020 GMC Sierra 2500 HD Denali
2020 GMC Sierra 2500 HD SLE
2020 GMC Sierra 2500 HD SLT
2020 GMC Sierra 3500 HD AT4
2020 GMC Sierra 3500 HD Base
2020 GMC Sierra 3500 HD Denali
2020 GMC Sierra 3500 HD SLE
2020 GMC Sierra 3500 HD SLT
2021 Chevrolet Silverado 2500 HD Custom
2021 Chevrolet Silverado 2500 HD High Country
2021 Chevrolet Silverado 2500 HD LT
2021 Chevrolet Silverado 2500 HD LTZ
2021 Chevrolet Silverado 2500 HD WT
2021 Chevrolet Silverado 3500 HD High Country
2021 Chevrolet Silverado 3500 HD LT
2021 Chevrolet Silverado 3500 HD LTZ
2021 Chevrolet Silverado 3500 HD WT
2021 GMC Sierra 2500 HD AT4
2021 GMC Sierra 2500 HD Base
2021 GMC Sierra 2500 HD Denali
2021 GMC Sierra 2500 HD SLE
2021 GMC Sierra 2500 HD SLT
2021 GMC Sierra 3500 HD AT4
2021 GMC Sierra 3500 HD Base
2021 GMC Sierra 3500 HD Denali
2021 GMC Sierra 3500 HD SLE
2021 GMC Sierra 3500 HD SLT

Air Freight Prohibited: false
Not Carb Approved: false
Ltl Freight Required: false
Prop 65: Y
Part Type: automotive
Epa: N/A
Carb Acknowledgement Required: false
Regular Stock: t
Units Per Sku: 1