
Shipping Estimate
USA
- USA
- CAN
- USA
- CAN
Ships within 48 hours · Estimated delivery Jul 8 - Jul 13
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 thermal bypass valve upgrade for your 2017-2019 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 adds even more heat dissipation. This 2017-2019 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 |
|---|---|---|---|
| 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
4.5 ★★★★★
Based on 1345 reviews
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Product Reviews
★★★★★ 5
Great solution for nighttime coughing.
Size: 40 Count (Pack of 3)
My dental hygienist recommended this when I told her I used a cough drop during the night bc I coughed. Obviously cough drops are not good for your teeth, and I found these serve the same purpose! They stick to the roof of your mouth & provide moisture all night long. So glad I found out about them. Pleasant taste - lasts all night.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 10, 2026
★★★★★ 5
These work!!!!
Size: 40 Count (Pack of 1)
I was waking up with several times a night super dry mouth even after drinking water. These tablets cured the dry mouth and now I am back to sleeping all night
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 28, 2026
★★★★★ 3
Lasted about an hour
Size: 40 Count (Pack of 1)
Today I used my first mint flavored melt, it lasted for exactly an hour. I didn’t have super high expectations for this to last 8 hours, but want to see if it would improve my overall enamel and prevent cavities. I was hoping it could help my night time dryness from a chronic stuffy nose and sleeping with my mouth open. I placed it upper molar area, but I think it’s good even still.
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Reviewed in the United States on May 5, 2026
★★★★★ 5
No more dry mouth in the mornings
Size: 40 Count (Pack of 1)
Finally waking up without dry mouth. I do have to use 1 on each side, and they’re hard to stick on, but honestly worth it. I’ve been getting cavities from dry mouth due to medications, and I’m so glad I’ll be able to prevent them from getting worse.
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Reviewed in the United States on June 1, 2026
★★★★★ 5
Amazing product!
Size: 40 Count (Pack of 1)
This is something that actually works! I am amazed at these dry mouth melts! They work great and I am very happy after trying multiple products that never seemed to work. The only complaint I would have is that they dont last all night for me, so I just use 2. but I am very satisfied with them and how good they work.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 24, 2026
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