2025+ Toyota 4runner Transmission Cooler Kits

Keep your transmission temperatures under control when towing, wheeling, or driving in extreme heat.

Designed by an engineer. Built specifically for the latest-generation Tacoma, Land Cruiser, and 4Runner. Tested in the real world. (fitment not 100% confirmed for any vehicle other than 4runner at this time)

These transmission cooler kits were developed specifically for the latest generation of Toyota trucks and SUVs, and work perfectly fine with both the hybrid and non-hybrid models. The CNC press-broke aluminum mounting bracket provides a clean, secure installation using existing factory mounting locations—no drilling or universal mounting straps required. It’s the only transmission cooler kit on the market designed to be compatible with winch-equipped vehicles.

Fits:

2024 - Present Tacoma (UNCONFIRMED)

2024 - Present Land Cruiser LC250 (UNCONFIRMED)

2025 - Present 4runner

Why Add a Transmission Cooler?

Heat is the biggest enemy of automatic transmission fluid and transmission life.

Under demanding conditions such as towing, off-roading, steep grades, slow-speed driving, heavy loads, and high ambient temperatures, transmission temperatures can climb significantly. This is especially true with the latest generations of Toyotas, there have been alot of reports of overheated transmissions. That’s why I purchased a 2026 4runner to develop a transmission cooling solution.

Most of my customers tell me the same thing: “Adding this cooler was a no-brainer.” 

Don't Rely on the Factory Temperature Gauge

The factory transmission temperature display is essentially a dummy gauge with no actual temperature numbers. When the indicator is sitting at its normal center position, actual transmission temperature can vary roughly from 140°F to 200°F without the indicator noticeably moving.

That means the factory display gives you very little warning that transmission temperatures are beginning to climb.

Don't wait for the transmission temperature warning light. The warning light does not illuminate until temperatures are at 300°F. At those temperatures, the transmission fluid has already been subjected to extreme heat and the fluid needs replaced.

The goal isn't to wait for the warning light—it's to keep the transmission from getting that hot in the first place and to monitor the temperature accurately.

An auxiliary transmission cooler helps control ATF temperatures before they reach those extremes, providing lower and more stable operating temperatures during severe-duty use.

Derale 16-Row Series 10000 Stacked-Plate Cooler

My kits use the Derale 16-row Series 10000 stacked-plate cooler, providing substantial cooling capacity in a compact package, well suited to the latest-generation of Toyotas. Stacked plate designs are the highest performance cooler designs conventionally available and outperform same-sized tube-and-fin designs.

Cooler Specifications:

16-row stacked-plate design
32,000 BTU/hr heat-rejection rating
0.31-quart fluid capacity
13" wide × 5-9/16" tall × 2" deep
Furnace-brazed aluminum construction
Full 2" deep turbulator-equipped plates
Integrated mounting points
Black powder-coated finish

The stacked-plate construction provides excellent heat transfer in a compact package. Internal turbulators increase fluid contact with the cooler's heat-transfer surfaces, helping efficiently transfer heat from the ATF into the passing airflow.

The cooler's 0.31-quart internal capacity also increases the transmission system's total fluid capacity, adding additional thermal mass while the 16-row core provides substantially more surface area for rejecting heat.

Its compact 13" × 5-9/16" footprint provides substantial cooling capacity without unnecessarily covering a large portion of the radiator and A/C condenser.

Iconic Fabrication Offroad Mounting Bracket

The cooler is mounted using an Iconic Fabrication Offroad vehicle-specific bracket. Prototypes were developed using actual 3D vehicle scans. Multiple cooler manufacturers have been consulted regarding the best way to support the cooler. The cooler has been placed as close to the condenser as reasonably possible to ensure the factory electric fan pulls the maximum amount of air through it.

CNC press-brake formed from .125" 5052 aluminum

Winch compatible

No drilling required

Uses existing factory mounting locations

Designed specifically around the vehicle and cooler

Made in the USA

No universal zip-tie mounts, improvised brackets, or drilling into your Toyota. No need to choose between a winch and a transmission cooler—my cooler setup is designed to work with winch-equipped vehicles. 

What About Airflow?

At first glance, you may notice that the cooler isn't mounted directly in the highest-airflow area of the grille and that a portion of the mounting structure sits in front of it. This was intentional.

The mounting location was chosen to balance cooling performance with another major design goal: winch compatibility. Rather than placing the cooler where it could interfere with a winch installation, the kit positions it in a compact location that allows you to run both.

Although the cooler isn't sitting directly in an unobstructed grille opening, it still receives airflow. The cooler is mounted close to the A/C condenser, where the vehicle's electric cooling fan creates a pressure differential that draws air through the condenser and surrounding heat exchangers—including the auxiliary transmission cooler. Vehicle movement provides additional airflow while driving.

Most importantly, I didn't simply assume the mounting location would work—I tested it in the real world. The test data demonstrates that the cooler effectively reduces and controls transmission temperatures in this location.

There are always packaging compromises when adding components to the front of a modern vehicle. My goal wasn't to find the location that looked best on paper—it was to develop a system that delivered measurable cooling performance while preserving the ability to install a winch. Because nobody wants to have to choose between the two.

Real-World Testing:

I was frustrated by the lack of transparency in the industry, where customers are often left guessing about how well an aftermarket transmission cooler actually performs. So I decided to put my money where my mouth is and publish real-world test results. Real data, real testing, and real results—that’s something that sets Iconic Fabrication apart. 

Test #1

This test was performed during normal highway driving in my stock, non-hybrid 2026 4Runner TRD Off-Road.

One of the most interesting results was that the transmission fluid warmed up at nearly the same rate with and without the auxiliary cooler. My 4runner does NOT have the built in thermostat on the side of the transmission. Adding the cooler did not significantly increase transmission warm-up time. This will debunk those that say aux transmission coolers make their fluid “too cold”. The similar warm-up rates can be attributed to the pre-existing small transmission-fluid heat exchanger, which uses engine coolant as a heat source when the transmission is cold. Since engine coolant warms relatively quickly after startup, heat transfers from the warmer coolant into the colder ATF, helping bring the transmission fluid up toward operating temperature. 

The difference became clear once temperatures began to stabilize. Without the cooler, ATF temperature continued to climb, while with the Iconic Fabrication cooler installed, it leveled off approximately 24°F cooler.

You may notice that the blue line appears slightly more erratic than the red line. This is simply due to minor real-world differences in vehicle speed, stops, starts, and other driving conditions between the two test runs.

 

Test #2

I hooked up my 4600 lb dump trailer onto my 2026 4runner and performed a towing test to evaluate the cooler under extreme conditions. The same 21 mile loop was driving with and without the cooler. The results speak for themselves. 

Further Testing:

I plan to perform additional off-road testing with and without the cooler, and possibly a towing torture test to demonstrate how the system performs under conditions that could otherwise lead to excessive transmission temperatures. An extreme-temperature test should be particularly interesting. As transmission fluid gets hotter relative to the outside air, the temperature difference across the auxiliary cooler increases, allowing it to reject heat at a greater rate. In other words, the harder the transmission is working and the more temperatures begin to climb, the more heat-rejection potential the auxiliary cooler has. Based on this principle and the results I've seen so far, I expect the difference between the factory system and the Iconic Fabrication cooler setup to become even more pronounced under severe conditions—but I'll let the real-world test data speak for itself. This is demonstrated by the increasingly larger temperature difference between the graph lines as the test progressed and the temps got higher.

OPTIONAL UPGRADES:

ABA Nova Stainless Steel Hose Clamps - Made in Sweden

These high-quality Swedish-made clamps provide even clamping pressure around the transmission cooler hose and are a significant upgrade over inexpensive generic worm-drive clamps. These are the best hose clamps you can buy.

Magnefine Inline Transmission Filter

Select in drop down menu.

Add a Magnefine 3/8" inline transmission filter (P/N 3810000) for additional filtration of the ATF circulating through the cooler circuit. The Magnefine combines conventional filtration with a powerful internal magnet to capture both normal debris and fine ferrous wear particles. It provides an easy-to-service additional layer of protection for your transmission. Trusted by OEM’s such as Ford in their transmission repair kits, these are the best filters on the market.

Veepeak OBDCheck BLE

Link to purchase on my website

I strongly recommend monitoring actual transmission temperatures, especially when towing, wheeling, or operating the vehicle under severe conditions. A Bluetooth OBD-II adapter such as the Veepeak OBDCheck BLE can be paired with a compatible free or paid phone app to monitor actual transmission temperature in real time, directly from the vehicle. Instead of relying on the factory gauge, you'll be able to see exactly how hot the transmission is getting and how effectively your auxiliary cooler is controlling temperatures. This is one of the newest OBD readers available and is the one I use in my personal 2026 4runner.

I highly recommend the free “Torque” phone app for easy setup or the free “Car Scanner ELM” phone app for more advanced use. At the time of testing the “Car Scanner ELM” app was the only app I could get to show transmission temperatures on the latest generation of Toyotas.

Glove Box Blackout Vinyl

Link to purchase on my website

Cool add-on item!

Built for every vehicle

While this setup is designed for Toyota owners who use their vehicles for:

Towing • Off-Roading • Mountain Driving • Hot Weather • Overlanding • Heavy Loads

I have seen transmission temps of 200 degrees on the flat highway on my stock 4runner after only 30 minutes of driving. So there is no doubt that even a stock truck used in a standard way can benefit from the additional cooler.

Rather than adapting a generic universal transmission cooler, the Iconic Fabrication Offroad system combines a proven stacked-plate cooler with a purpose-built mounting solution designed specifically for the vehicle. The no-compromise design still allows for a winch to be installed while providing plenty of cooling performance. I’ve eaten, slept, and breathed transmission coolers since releasing my first FJ Cruiser kit back in 2021. Years of designing, testing, and refining Toyota transmission cooler setups went into this latest kit. I have cut bulk quantity deals with the manufacturers of all these parts to ensure you are getting the lowest price, saving you $ from buying all the parts individually.

From the beginning, one of the goals was to make sure adding a transmission cooler didn’t mean giving up the ability to run a winch. The new kit was designed around the limited space available at the front of the latest-generation Tacoma, Land Cruiser, and 4Runner, positioning the cooler and mounting hardware to remain compatible with winch-equipped setups.

Development didn't stop at simply finding a place to mount a cooler. I consulted Toyota's Factory Service Manual and service information throughout the design process to better understand the factory transmission cooling system, fluid routing, operating strategy, and proper service procedures. 

No choosing between a winch and a transmission cooler. This kit was designed from the start to let you run both.

Engineered, test-fit, and assembled using high quality components selected for long-term reliability. If you’re driving a $50,000+ truck, it deserves quality components.

Installation Notes

• Remove the plastic bumper/grill assembly according to the Yota Xpedition Youtube video (linked). https://www.youtube.com/watch?v=abHYZNZp6J8 Removing the grill/bumper is not as bad as it looks, it only takes me 10 minutes to remove it after some experience.
• The condenser fins on these trucks are extremely fragile, a single finger tip push can bend the fins. Take extreme caution or cover the condenser with a piece of cardboard.
• Loosely install a single Iconic Fabrication bracket first, then loosely bolt the cooler to that bracket, then loosely install the second bracket. There is no way to bolt the cooler to the brackets first and fit it to the truck, there isn’t enough room. Each component must be installed one at a time.
• Tighten down all the bolts to secure the cooler firmly in place. Plan the hose routing. Toyota actually paint marks the transmission hoses with red and blue for hot and cold routing which makes finding the right hoses to connect to pretty easy.

Derale Cooler Return Policy

This policy supersedes our standard return policy for the Derale cooler itself.

Due to the cost of the Derale cooler, returns will only be accepted under the following conditions:

• The cooler is defective or leaking, and photos documenting the issue are provided; or
• The cooler is new and uninstalled, with no installation marks, damage, or signs of use.

Once a Derale cooler has been installed, it cannot be returned unless it is confirmed to be defective or leaking.