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.
All products are shipped out from one of the Signature Autohaus shipping locations. Signature Autohaus drop ships some products and ships direct others. All products are shipped via FedEx, UPS, DHL or another qualified shipping carrier.
Special arrangements may need to be made for international orders and oversize packages.
In the event a product arrives damaged to your location, please follow the steps listed below. All damaged items must be reported to the shipping carrier immediately and you must notify Signature Autohaus within 5 days of receiving your order. If these steps are not followed, your shipment may not be able to be a candidate for a claim.
Complete the Shipping DAMAGE Claim Form by contacting the carrier that delivered your package.
1) Keep the product and its original packaging and box
Make a list of the damaged or lost item(s)
2) Signature Autohaus will contact the shipper once we receive the email info above to schedule a pickup, DO NOT send it back to us
3) Once the product is picked up and inspected by Signature Autohaus and or Supplier, a replacement or credit will be issued.
4) The Shipping Rates shown at time of checkout our dimensional rate only. If your shipment weight is to much then contact us for a shipping quote. If there is an error in the shipping rate quoted we will contact you and let you know of the changes. International orders(Outside the USA) are not automatically processed as we may require additional information from you.
If a product is ordered and not wanted, the UNUSED item can be returned for a 35% restocking fee. Shipping is not refundable in either direction. All items wanting to be return MUST be reported within 30 days of the original invoice date. No items will be returnable after 30 days. All products shipped from the Signature Autohaus warehouse are shipped via FedEx or Freight and require a signature when delivered. Some packages shipped from the manufacturer may or may not require signatures for package release. Fedex, UPS, and DHL have package pick up locations if you are unable to sign for the package. If the package is returned to Signature Autohaus or manufacturer, you will be responsible for the return shipping costs and pay a 35% restocking fee. These fees will be charged to your account on file.
SIGNATURE AUTOHAUS DOES NOT REFUND SHIPPING CHARGES. If you modify, install, or alter the item in any form, we cannot accept it as a return, will not cover any expenses related to the product or installation, and you maybe be required to purchase a replacement.
In the event that the product you ordered is sent either incorrectly or processed wrong by Signature Autohaus, we will arrange for the package to come back to us and ship out a replacement. We will evaluate the situation before we determine the shipment was incorrect.
To return a item back to us, please do the following:
1. Contact our Customer Service Department to receive a RMA number. All packages returned without a Returned Merchandise Authorization number will be refused.
2. Package the item up in original packaging unless deemed unuseable
3. Include the UNUSED parts and any additional information that was included
4. Include a copy of your receipt
5. Write a brief description of the problem with the product
6. If you have a receipt for the return shipping include as well
7. We DO NOT accept any freight collect packages
8. Once we have received the above information we will notify you via email or phone and let you know the status.
