SKU: 25597115635

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

Sale price$89.95 Regular price$99.95
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Ships within 48 hours · Estimated delivery Aug 22 - Aug 27

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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 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.
Shipping Notes
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Exchange/Return Notes
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SKU: 25597115635

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4.6 ★★★★★
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JCMIV63
Houston, US
★★★★★ 5
Cushioned, comfortable, stylish and a rubber sole!
Size: 10, Color: Brown
These shoes check multiple boxes for me, comfortable, cushioned, rubber sole and stylish. As my feet grow old and worn out, I'm on a constant search for comfortable, cushioned shoes that are suitable for work and dressier occasions. I have tried many expensive shoes that look great but either lack cushioning, arch support and or comfort. One of the nice things is these shoes have a rubber sole, where most cushioned shoes have the foam soles which are great, but they tend to lack grip particularly when its damp/wet. They have average arch support, but the insole is removable and I put my own cushioned arch support. Love these!
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Reviewed in the United States on April 6, 2026
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Verified Purchase
DDD Projects
Omaha, US
★★★★★ 5
OG Style
I am a big fan of Bruno Marc shoes. Over the years they have provided comfortable and affordable boots and shoes. These blue, tan and white soled dress sneakers are no exception. They have a nice finished look that makes them both causal and dressy. The lightweight style is still warm enough for colder mid-west winters. The box of the toes is wide and comfortable. The insole is well padded and a pleasure to wear. This is another fine pair of shoes to add to my collection and yours.
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Reviewed in the United States on January 14, 2026
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Premium Reviews
Cuba, US
★★★★★ 5
Must buy: Comfort + Casual + Well Made / Ventilated
Size: 8, Color: Brown
Just buy it! I have put in roughly 15,000 steps in this shoes in 10 days and I can't believe how comfortable they are after this much rough use in short amount of time. I highly recommend this shoes to anyone looking for comfort in casual style.
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Reviewed in the United States on May 4, 2026
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William W.
Grantham, US
★★★★★ 5
WIDE Dress Shoes With SUPPORT
Size: 10.5, Color: Brown
I've seen dress shoes and worn dress shoes before, but these are simply the best dress shoes I've ever worn my entire life. 99% of dress shoes have the same problem, they have the thinnest little soles that offer no support. BRUNO MARC HAS SOLVED THE PROBLEM. These dress shoes not only support wide feet like mine who historically have had and still have little support in the market, but Bruno Marc has wide options that fit perfectly, and the support with the thick foam sole is so needed and awesome. I had a pleasant surprise putting these things on and there being some tactile grip enhancers inside the shoe so you can feel the shoes better and get a little tickle / massage while you're at it. These things are dripping with style, easy to wear, and while they might look firm on the outside, on the inside the shoe just has such a nice flexibility and foamy feel, the top where the top of your feet feel the roof of the shoe, it has such perfect ooey gooey support I can't believe it. The outside sole also has this neat tactile feel. The durability looks good and feels good for now.
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Reviewed in the United States on September 28, 2025
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Verified Purchase
Maricris Aldaba
Boise, US
★★★★★ 5
Classy!
Color: All Black-Black
Got this as a gift for my husband, it fit perfectly! You can adjust it accordingly, but luckily, we didn’t have to. My husband loved the classic look, he plans to wear this more than his Apple Watch. Loved how prime was available, arrived fast!
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Reviewed in the United States on February 28, 2025

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