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Mishimoto 2017+ GMC 6.6L Duramax L5P Transmission Thermal Bypass Valve Kit
- Regular price
- $175.00 USD
- Regular price
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- Sale price
- $175.00 USD
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Description
xThe 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.
Vehicle Fitment
xShipping
xSHIPPING & DELIVERY INFORMATION
Free Shipping
- Eligibility: Orders over $99 in the USA & Canada.
- Exceptions: Oversized or heavy items may incur extra fees (we’ll notify you before shipping).
- Non-Eligible Areas: Vancouver Island, Yukon, NWT, Nunavut, Alaska, Hawaii, Puerto Rico & other U.S. territories.
Fast Shipping
- Processing: Orders placed before 2 PM usually ship the same day.
- Delivery Time: 2–5 business days via Purolator, FedEx, or Loomis Express.
- Note: Delivery may take longer for distant warehouses or inter-warehouse transfers.
Shipping Limitations
- No P.O. Boxes: Please provide a physical address.
- Remote Areas: Free shipping excludes remote regions.
Special Orders & Backorders
- May incur additional handling fees (discussed before shipping).
- You may cancel if costs are too high for a full refund.
Warranty
- For internal damage or missing parts, contact the manufacturer directly for faster service.
- After 30 days, contact the manufacturer first — if unresolved, our team will assist.
Oversized Items
- Shipped via LTL Freight (items over 150 lbs or large dimensions).
- We’ll confirm any added costs before shipping.
- Examples: Large Fridges, Oversize Toolbox or Tanks, Drop in Bed liners, Wheel to Wheel Step bar & Running Boards, Large Roof Cargo Box, Heavy Bumpers, RV Doors, Oversize, Roof Tent, Large gas tank, Oversize Grille Guards, Fifth Wheel Hitch, Sofa , Trailer Axle.
- Special Handling Fees: Items like batteries may incur additional shipping fees.
Returns & Cancellations
In-Stock Items
- Cancel before shipment; once shipped, standard return policy applies.
- 20% restocking fee, excluding oversize item. Both way shipping is customer responsibility under store error.
Backorders / Special Orders
- 5% restocking fee applies if canceled within 30 days.
- Non-cancellable once shipped from the manufacturer.
- Refused Deliveries: Refund minus shipping & restocking fees (excludes special orders).
- Payment Disputes: Chargebacks do not cancel orders — please contact us directly.
Core Fees
- Not included in the purchase price.
- Refundable upon return of the old part in usable condition.
If you have any questions or need assistance, please reach out to us at 800.292.4173 or support@mytruckpoint.ca.
Why Us
xWhy Choose MyTruckPoint?
When it comes to your truck, compromise is not an option. At MyTruckPoint, we deliver the quality, speed, and trust that professionals across Canada depend on every day.
🇨🇦 Trusted Across Canada for 10+ Years
A decade of proven reliability serving truck owners, fleets, and businesses nationwide. We’ve built our reputation by delivering consistent quality and dependable service.
📦 100,000+ Orders Delivered
Over one hundred thousand successful orders — every one backed by accuracy, speed, and customer satisfaction you can count on.
✅ Authorized Dealer of Leading Brands
No knock-offs. No compromises. Only genuine parts from top-tier brands, ensuring performance, safety, and long-term value.
💪 Built for Performance & Durability
Our parts are selected to handle real-world demands — tough jobs, long hauls, and harsh conditions. Because your truck deserves the best.
💰 Competitive Pricing Without Cutting Corners
Premium quality doesn’t have to mean premium prices. We deliver exceptional value so you get more for every dollar spent.
⚡ Fast, Reliable Shipping
Downtime costs money. That’s why we process orders quickly and deliver efficiently — so you can get back on the road faster.
🧠 Expert Support You Can Rely On
Not sure what you need? Our experienced team is here to guide you with honest advice and the right solutions — every time.
🤝 Customer-First Commitment
We stand behind every order. Your satisfaction isn’t optional — it’s our priority.
MyTruckPoint — Trusted by Thousands. Built for the Road.
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