2004.5-2007 Ram 5.9L Cummins Transmission Coolers
Keeping your Ram's transmission cool is absolutely critical if you want to avoid going into limp mode or causing serious damage to your truck's transmission. Tier One's transmission coolers for 2004.5-2007 Ram 5.9L Cummins trucks help reduce your Ram's transmission temperatures, even when it's generating a ton of heat from performance upgrades or when your truck is towing big trailers, toy haulers, fifth wheels, campers, boats, or whatever else you have in mind. A performance Ram 5.9L Cummins transmission cooler will give your truck much lower transmission temperatures which makes your towing and hauling life a heck of a lot easier and preserves the lifespan of your transmission. Tier One has both drop-in replacement transmission coolers as well as universal auxiliary transmission coolers if you need even more transmission cooling for your Ram truck.
If your truck has already suffered from heat damage and is slipping in gear, a cooler alone won't fix the internal clutches, so you may need to look at replacing the unit with one of our 2004.5-2007 Ram 5.9L Cummins Complete Transmissions. An unlocking torque converter creates significant friction and heat, so to reduce heat generation at the source while improving towing performance, consider upgrading to one of our 2004.5-2007 Ram 5.9L Cummins Torque Converters. Sometimes overheating is caused by inefficient fluid routing or cross-leaks inside the case, but you can improve fluid flow and reduce operating temperatures by installing one of our 2004.5-2007 Ram 5.9L Cummins Valve Bodies. Another great way to help manage heat is by increasing your overall fluid volume, so add several quarts of extra capacity and help dissipate heat by adding a deep pan from our section of 2004.5-2007 Ram 5.9L Cummins Transmission Parts.
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About 2004.5-2007 Ram 5.9L Cummins Transmission Coolers
Heat is the number one killer of the 48RE transmission, and the 2004.5-2007 Ram 5.9L Cummins trucks are no exception. While the High Output 5.9L engine produces massive torque, it also generates significant heat that can quickly overwhelm the factory transmission cooler, especially when towing heavy loads up steep grades or sitting in stop-and-go traffic. Once transmission fluid temperatures spike, the fluid breaks down, leading to clutch slippage, seal damage, and eventually, a complete 48RE failure. To keep your 3rd Gen Ram running cool and reliable, Tier One offers high-performance cooling upgrades that vastly outperform the stock setup. Whether you need a massive auxiliary cooler with its own airflow source or a direct-fit replacement to upgrade the factory location, we have the solution to keep your transmission in the safe zone.
Types of 2004.5-2007 Ram 5.9L Cummins Transmission Coolers
We offer two primary ways to upgrade the cooling on your 2004.5-2007 Ram: adding a fan-assisted auxiliary cooler for maximum temperature drops or installing a high-capacity direct-fit cooler for a seamless factory-style upgrade. Auxiliary Fan-Assisted Coolers (The Tier One Kit): For trucks that see extreme duty—like heavy towing at slow speeds or aggressive off-roading—airflow through the grille is often the limiting factor. The Tier One Auxiliary Transmission Cooler Kit solves this by utilizing a Derale 15870 40-Row Hyper-Cool Extreme Remote Cooler. Because it has its own fan, it doesn't rely on your truck's speed to cool the fluid, making it a lifesaver for the 48RE.- Active Cooling: Equipped with a 10" waterproof/dustproof electric fan pushing 800 CFM, providing massive cooling power even when the truck is stationary.
- Extreme Capacity: The 40-row stacked plate design is rated at 67,000 BTUs per hour.
- Versatile Mounting: Can be mounted remotely anywhere space permits (like under the bed or behind the bumper) to keep heat away from the intercooler and radiator stacks.
- Direct Fitment: Installs directly into the factory location for a clean, hassle-free upgrade without cutting or custom bracketry.
- Superior Core Design: Features a significantly thicker core and increased fluid capacity compared to the stock unit, allowing for greater heat dissipation.
- Reliability: Built with durable end tanks and a robust core to handle higher pressures and temperatures than the OEM cooler.
