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

$103.95 USD$122.34 USD
Item is in stockHurry! Low inventoryItem is out of stock Item is unavailable
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SHIPPING - RETURNS - WARRANTY - CANCELLATION POLICY

*** Market Conditions after 2020 have changed the landscape of automotive parts. Although we try to stock 1000's of items in our multiple warehouse and use multiple distribution channels, having back-orders are unavoidable in today's market. If you are in need of a product quickly, we suggest email, message, or call us for availability so that we may explore your options.
Email: Sales@Speedzoneweb.com
Call: 407-846-8430
Text: 407-749-6314

Frequently Asked Questions


Brand: Mishimoto
SKU: MISMMTC-L5P-TBVFF
UPC: 840197710609
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+ 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 add even more heat dissipation. This 2017+ 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.

This Part Fits:

Year Make Model Submodel
2021 Chevrolet Silverado 2500 HD Custom
2017-2021 Chevrolet Silverado 2500 HD High Country
2017-2021 Chevrolet Silverado 2500 HD LT
2017-2021 Chevrolet Silverado 2500 HD LTZ
2017-2021 Chevrolet Silverado 2500 HD WT
2017-2021 Chevrolet Silverado 3500 HD High Country
2017-2021 Chevrolet Silverado 3500 HD LT
2017-2021 Chevrolet Silverado 3500 HD LTZ
2017-2021 Chevrolet Silverado 3500 HD WT
2020-2021 GMC Sierra 2500 HD AT4
2017-2021 GMC Sierra 2500 HD Base
2017-2021 GMC Sierra 2500 HD Denali
2017-2021 GMC Sierra 2500 HD SLE
2017-2021 GMC Sierra 2500 HD SLT
2020-2021 GMC Sierra 3500 HD AT4
2017-2021 GMC Sierra 3500 HD Base
2017-2021 GMC Sierra 3500 HD Denali
2017-2021 GMC Sierra 3500 HD SLE
2017-2021 GMC Sierra 3500 HD SLT


Our History

For 23 years Speedzone Performance LLC has been providing aftermarket car parts to Central Floridians and 1000's of customers online. What makes us different than all the other places online? We have 3 actual brick and mortar locations where were serve customers daily and find new ways to provide support and assistance to the automotive community at large. From our in house SPDZ1 Brand, to our constantly growing in stock inventory, we strive to make our customer service and ease of purchase stand out from the rest! We are also one of the largest automotive part financing providers anywhere in the United States, and continue to provide more options for our customers every year. We love what we do, and it shows in every product we sell and every new customer who becomes a part of our Speedzone Family.

Our Florida Locations

Kissimmee • Orlando • Tampa

Testimonials

We let our reviews speak for themselves.

4.9 average
914 reviews

Kissimmee

Orlando

Tampa

Great service at a fair price. I highly recommend them for all your performance needs. They have the know how to complete that project.

Donald Berry

Happy Customer

Google Review

Dropped off my 2022 Subaru WRX for Exhaust, spoiler, aeroflow dynamic kit, and they killed it. Quality work and amazing customer service. Speedzone gets you right.

Edward Roldan

Happy Customer

Google Review

They gave me the best price I could find after shopping around for a while. They are well informed and familiar with the products they sell, great communication and quick responses. I would no doubt purchase from them again. Solid company. Recommended. A+

Paul K

A Month Ago

Google Review

Came based on a work buddies recommendation. I was late by 30 minutes, confused my appointment time. But, 10/10 would come back. Came for a Downpipe and midpipe install. Not only was the gentleman accommodating, He ran into some issues, staff helped me out and pointed me into the right direction and got me going! They got my business and wouldn’t go anywhere else again!

Kiyo Gallimore

Verified Customer

Google Review

They Take Great Care Of Their Customers and Their Rates Are Better Than The Competition! They Also Respond Quickly And Have A Great Assortment Of Parts!

Jad

6 months Ago

Google Review

Absolutely love the customer service that you get with Speedzone Performance! All my questions are always answered in such a timely manner and this a big PLUS because I live out of Florida and for them to be on top of answering all my questions in such a way means a lot. Thank you all for the amazing customer service.

Daisy Vargas

Verified Customer

Google Review

My favorite place to go for anything car related, they have anything you could imagine & more. The people who work here are the coolest and most helpful people I’ve yet to meet at a car shop. They also don’t try to force sales on you and they genuinely help you with what you’re looking for, 100/10 shop!

Stephanie Trinidad

Loyal Customer

Google Review

The best of best, they are so nicely and kind people, yankee and billy more than the ones that runs the store they are a friend to everyone who walks in the store, very patient gets everyone what they need, everything you ask them they’ll answer your questions the best as possible, I love shopping there. They have the best prices, anything as car need you’ll find it there big shout-out to Yankee for being an amazing person and most important as a friend!! I love Speedzone!

Jansel Castillo

Loyal Customer

Google Review