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- USA
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- USA
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Ships within 48 hours · Estimated delivery Jul 12 - Jul 17
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For Your Every Summer RSVP, with Code: SUMMER15
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 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.This Part Fits:
| Year | Make | Model | Submodel |
|---|---|---|---|
| 2017-2019 | Chevrolet | Silverado 2500 HD | High Country |
| 2017-2019 | Chevrolet | Silverado 2500 HD | LT |
| 2017-2019 | Chevrolet | Silverado 2500 HD | LTZ |
| 2017-2019 | Chevrolet | Silverado 2500 HD | WT |
| 2017-2019 | Chevrolet | Silverado 3500 HD | High Country |
| 2017-2019 | Chevrolet | Silverado 3500 HD | LT |
| 2017-2019 | Chevrolet | Silverado 3500 HD | LTZ |
| 2017-2019 | Chevrolet | Silverado 3500 HD | WT |
| 2017-2019 | GMC | Sierra 2500 HD | Base |
| 2017-2019 | GMC | Sierra 2500 HD | Denali |
| 2017-2019 | GMC | Sierra 2500 HD | SLE |
| 2017-2019 | GMC | Sierra 2500 HD | SLT |
| 2017-2019 | GMC | Sierra 3500 HD | Base |
| 2017-2019 | GMC | Sierra 3500 HD | Denali |
| 2017-2019 | GMC | Sierra 3500 HD | SLE |
| 2017-2019 | 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:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy
4.2 ★★★★★
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Product Reviews
★★★★★ 4
Amazing but quality changed
Size: Large, Color: (002) Black / Black / Halo Gray
Love these socks so much, been buying them for about 4 years now!! Not giving them 5 stars anymore because the quality is different and not as good, durable and thick as before.
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Reviewed in the United States on July 10, 2025
★★★★★ 5
The best no show socks
The only no show socks I have ever found that do not slide down. These are very comfortable and the extra tab on the back provides comfort by keeping shoes from rubbing the back of your foot. The top of the sock also comes up high enough to cushion the top of your foot all while still remaining hidden while wearing tennis shoes or even with my hey dudes.
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Reviewed in the United States on November 30, 2025
★★★★★ 5
Great quality and fast shipping
Size: Medium, Color: (001) Black / Black / Castlerock
These socks are tight but after the first wash and dry , they fit perfect and NEVER slide off , ordered a second pack
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Reviewed in the United States on March 24, 2026
★★★★★ 5
Comfortable, Durable, and Stylish
Perfect gift choice! Excellent quality socks with a variety of colors to match any wardrobe.
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Reviewed in the United States on November 30, 2025
★★★★★ 5
Best no-show socks ever!
Size: 6-10, Color: Black
If you're tired of wearing socks that slip off and show in your sneakers, then you need to try these amazing socks! They are designed to stay in place, even after being active all day. They are incredibly soft and comfortable, and they are truly no-show, so you won't see them at all. I've been using these socks for years and have never had any issues. In fact, I love them so much that I've bought multiple packs, and my family members have started using them too. Don't waste any more time with those annoying socks that slip off and show - give these a try and you won't be disappointed!
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Reviewed in the United States on April 16, 2024