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.
Installation Instructions
- 245% larger core volume for serious heat dissipation - the oversized tube-and-fin core gives the transmission far more capacity to pull heat from the fluid under tow and heavy load.
- Tube-and-fin aluminum core built for sustained load - durable all-aluminum construction holds transmission temps in check through the heat of towing where stock cooling falls short.
- 173% more external fin area accelerates heat transfer - the added fin surface moves thermal energy from the fluid into the airstream far more efficiently than the stock cooler.
- Factory connections, no adapters required - the cooler uses the OEM transmission line connections for a complete bolt-on upgrade with no extra fittings or plumbing work.
- 137% more frontal area catches more cooling airflow - the larger frontal core area puts more of the cooler in the incoming airstream to drop fluid temps faster.
- Drops in without modification - confirmed direct fit for 2020+ Chevrolet and GMC Duramax L5P 6.6L trucks, with no cutting, fabricating, or adapter work required
- Own it for life - backed by Mishimoto’s Lifetime Warranty, your investment is protected long after install day.
