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Mishimoto

Mishimoto 2020+ Chevrolet / GMC Duramax L5P 6.6L Transmission Cooler

Mishimoto 2020+ Chevrolet / GMC Duramax L5P 6.6L Transmission Cooler

$368.99 USD
$386.00 USD $368.99 USD
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In stock

Shipping & returns

Shipping is calculated at checkout by size and destination. Most in-stock gear ships within a few business days; large freight items (campers, racks, bumpers) are made to order. Wrong fitment? Send it back within 30 days — we'll help you find the part that does fit.

Fitment & build help

Not sure if this fits your platform? Tell us your year, make, model, and trim — we'll confirm before you order. For bigger builds, we'll help you plan the full stack.

Warranty

Every product on this site ships through authorized channels with full manufacturer warranty. If something breaks in normal use, we'll help you get it resolved.

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The factory transmission cooling on the 2020+ Chevrolet and GMC Duramax L5P 6.6L is sized for stock duty, and fluid temperatures climb fast under the sustained load of towing and heavy hauling. Heat is what wears a transmission out. The Mishimoto Transmission Cooler attacks the problem with raw capacity: a tube-and-fin core with a 245% increase in core volume over stock, giving the system far more headroom to keep fluid temperatures in a safe range when the truck is working hardest.----The core also adds a 137% increase in frontal area, putting more of the cooler directly in the incoming airstream, and a 173% increase in external fin area to move heat from the fluid into the air more efficiently. All-aluminum construction handles the thermal demands of stock and modified Duramax trucks alike, and the cooler retains the factory transmission line connections for a clean, complete upgrade with no additional adapters or plumbing.----Direct fit for the 2020+ Chevrolet and GMC Duramax L5P 6.6L. No drilling, cutting, or modification required. Backed by the Mishimoto Lifetime Warranty.

This Part Fits:

Year Make Model Submodel
2021-2026 Chevrolet Silverado 2500 HD Custom
2020-2026 Chevrolet Silverado 2500 HD High Country
2020-2026 Chevrolet Silverado 2500 HD LT
2020-2026 Chevrolet Silverado 2500 HD LTZ
2020-2026 Chevrolet Silverado 2500 HD WT
2024-2026 Chevrolet Silverado 2500 HD ZR2
2020-2026 Chevrolet Silverado 3500 HD High Country
2020-2026 Chevrolet Silverado 3500 HD LT
2020-2026 Chevrolet Silverado 3500 HD LTZ
2020-2026 Chevrolet Silverado 3500 HD WT
2020-2026 GMC Sierra 2500 HD AT4
2024-2026 GMC Sierra 2500 HD AT4X
2020-2021 GMC Sierra 2500 HD Base
2020-2026 GMC Sierra 2500 HD Denali
2024-2026 GMC Sierra 2500 HD Denali Ultimate
2022-2026 GMC Sierra 2500 HD Pro
2020-2026 GMC Sierra 2500 HD SLE
2020-2026 GMC Sierra 2500 HD SLT
2020-2026 GMC Sierra 3500 HD AT4
2020-2021 GMC Sierra 3500 HD Base
2020-2026 GMC Sierra 3500 HD Denali
2024-2026 GMC Sierra 3500 HD Denali Ultimate
2022-2026 GMC Sierra 3500 HD Pro
2020-2026 GMC Sierra 3500 HD SLE
2020-2026 GMC Sierra 3500 HD SLT

  • Ships from San Diego

    We ship from our San Diego dealer network. Most in-stock gear goes out within a few business days — shipping's calculated at checkout by size and destination.

  • Wrong fitment? We make it right.

    If a part doesn't fit your platform the way it should, send it back. We handle the return and find you the part that does.

  • Authorized dealer support

    Every product moves through proper channels. Full manufacturer warranty, real tech support — no gray-market headaches.