SKU: 97593175093

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

Sale price$128.68 Regular price$142.98
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Ships within 48 hours · Estimated delivery Aug 14 - Aug 19

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Description

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

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 thermal bypass valve upgrade for your 2017+ Chevrolet/GMC 6.6L Duramax. 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 kit includes a fully serviceable thermostat for fast warm-up in cold climates. This kit also includes a thermostat bypass that can be installed to provide constant cooling in warm climates or for use in extreme driving/towing conditions. 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 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
Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
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Exchange/Return Notes
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  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
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SKU: 97593175093

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Mongoose
Massapequa, US
★★★★★ 5
Great for carnivore.
Size: 30 Fl Oz (Pack of 1)
Great quality oil for Carnivore / Keto! A few precautions: - Start slow; too much too soon will cause gastric issues. 1/2tsp for the first few days, then increase to 1tsp for a few days and so on until you work up to a level you can tolerate. Get a shot glass with measurement lines. - Stay hydrated. MCT is a diuretic and may cause headaches if you are not hydrated. Consider taking some electrolytes with it and plenty of water. - If you find it gives you jitters; consider taking it with food. It can cause a little bit of a "high" if your not used to the immediate energy / mental clarity boost; which may freak some people out. Taking it with food will slow down the onset so it's not hitting you like a ton of bricks. - I personally don't mind the texture but it definitely goes down easier if it's cold; ymmv. No taste, but it's going to make your mouth feel oily for a minute.
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Reviewed in the United States on May 28, 2026
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Castiel
Lexington, US
★★★★★ 4
Good quality oil, but the dispenser is a nightmare to use
Size: 16 Ounce (Pack of 1)
This MCT oil is truly odorless, colorless, and tasteless. While the oil quality itself seems good, the dispenser on the cap is terrible. I understand the design is meant to keep air out, but you have to squeeze the bottle quite hard to get any oil out, making it impossible to control the flow. Every time I try to pour a small amount onto a spoon, it shoots out and splatters all over my hands and the counter. Now, I just take the entire cap off, pour it onto the spoon, and close it back up. Great oil, but the bottle design needs a major update.
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Reviewed in the United States on April 30, 2026
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France Ciel d'August
Waukegan, US
★★★★★ 5
Very good product ,,, I have recommended it to friends ..
Size: 30 Fl Oz (Pack of 1)
Silky texture and tastes very good... great price .. I have reordered and will keep re ordering
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Reviewed in the United States on May 8, 2026
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Sheila A.
Draper, US
★★★★★ 5
No better way to get your MCT. No harsh taste or after taste.
Size: 30 Fl Oz (Pack of 1)
Great product! The oil is indeed flavorless and easy to just drink straight.
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Reviewed in the United States on June 1, 2026
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Lee Weinland
Omaha, US
★★★★★ 5
Best MCT oil in the market
Size: 30 Fl Oz (Pack of 1)
Love this stuff. Best value for MCT oil. Super high quality. I'd buy it in 55 gallon drums if they sold it tgat way!
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Reviewed in the United States on June 1, 2026

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