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Mishimoto MMTC-L5P-TBVFF Full-Flow Transmission Thermal Bypass Valve Kit for 2017+ Duramax L5P

(2017-2021 Chevrolet Silverado 2500 HD; 2017-2021 Chevrolet Silverado 3500 HD; 2017-2021 GMC Sierra 2500 HD; 2017-2021 GMC Sierra 3500 HD)

Manufacturer

Picture for manufacturer Mishimoto

Part Number

MMTC-L5P-TBVFF
7 reviews
Sale Price

$118.95

In Stock (10+)

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Usually delivered within 2 days

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Product Details

The Mishimoto MMTC-L5P-TBVFF Full-Flow Transmission Thermal Bypass Valve Kit is engineered to maximize transmission cooler efficiency in 2017+ Chevrolet and GMC 6.6L Duramax L5P diesel trucks. This performance upgrade eliminates the factory failure-prone bypass valve, allowing full-flow operation for optimal heat dissipation and extended transmission life.

Key Features:

  • CNC-machined billet aluminum construction for maximum durability
  • Full-flow design allows transmission cooler to operate at maximum efficiency
  • Eliminates OEM bypass valve, a common failure point in the cooling system
  • Integrated heat-sink fins provide enhanced heat dissipation and aggressive styling
  • Durable anodized finish resists corrosion and wear
  • Direct-fit design works with stock transmission cooler lines—no modifications required
  • Installs in under 1 hour with basic hand tools
  • Backed by Mishimoto Lifetime Warranty

This thermal bypass valve kit is specifically designed for 2017 and newer Chevrolet Silverado and GMC Sierra trucks equipped with the 6.6L Duramax L5P engine. By maintaining consistent coolant flow through the transmission cooler, this kit helps prevent overheating during towing, hauling, and high-performance driving conditions.

Products specifications

Fits

2017-2021 Chevrolet Silverado 2500 HD; 2017-2021 Chevrolet Silverado 3500 HD; 2017-2021 GMC Sierra 2500 HD; 2017-2021 GMC Sierra 3500 HD

Color

Silver

TechSpec Engine Codes

L5P--6.6L Duramax

TechSpec Chassis Codes

2500--3500

Prop 65

WARNING: Cancer and Reproductive Harm - www.p65warnings.ca.gov

TechSpec Includes

(1) CNC-Machined Billet Aluminum Thermal Bypass Valve--(2) 7/8-inch X 14 Quick-Disconnect Transmission Line Fittings--(1) Transmission Line Mounting Plate--(1) Transmission Line Mounting Plate Bolt--Mishimoto Lifetime Warranty

Install Difficulty

1

TechSpec OEM Activation Temperature (F)

185

TechSpec Note

Mishimoto does not recommend customers in cold climates install the thermostat bypass to avoid overcooling of the transmission fluid----This performance thermostatic bypass valve only fits vehicles equipped with the Allison automatic transmission----

TechSpec Applications

GMC Sierra 2500HD V8 (6.6L Diesel) 2017-2019--GMC Sierra 3500HD V8 (6.6L Diesel) 2017-2019--Chevrolet Silverado 2500HD V8 (6.6L Diesel) 2017-2019--Chevrolet Silverado 3500HD V8 (6.6L Diesel) 2017-2019

Great

Quick delivery

This has two different part numbers and I am not 100% sure what I am going to receive. I think and want both, but not sure.

Great customer service

Super easy to search and tons of available OE products

Really good

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