Cool Cousins - Toyota Tacoma and FJ Cruiser Transmission Cooler R&D, Part 2 - FJ Cruiser Design Plans and Prototyping

Cool Cousins - Toyota Tacoma and FJ Cruiser Transmission Cooler R&D, Part 2 - FJ Cruiser Design Plans and Prototyping

Toyota's toughness isn't just limited to the multifaceted pick-up trucks in their lineup. Some of these trucks developed super-specific skills like navigating challenging terrain without breaking a sweat. Enter the FJ Cruiser. This towering off-roader might not share the same skeleton as its pick-up cousin, the Tacoma, but both of these trucks share the same beating heart dispersing power and traction to dominate dunes, crawl through crevasses, and ford raging rivers, all of which are not places you'd want your transmission to give out.

Unlike the utilitarian-based Tacomas, the FJ Cruiser lacks the external support for maintaining transmission fluid temperatures. Both platforms utilize a heat exchanger built into the radiator's cold-side end tank, which manages the automatic transmission fluid, or ATF, temperatures on both extremes. Still, the FJ is missing the additional liquid-to-air cooler that provides a cooling boost when the vehicle is under heavy load. Make sure to head back to our first post to check out the importance of keeping transmission fluid at the proper temperature.

While these off-roaders may not be towing or hauling heavy payloads, the treacherous terrain that these FJs encounter can put just as much stress on the transmission, which calls for some additional cooling power. To keep things moving smoothly along the trail, we're planning to update the FJ's cooling system to make it on par with the Tacoma.

These trucks share a transmission, and now they'll share the same cooling system

Where the Tacoma's transmission cooler only needed a size update, the FJ requires some more legwork from our engineering team. The plan is to mount this cooler in a similar location to the Tacoma, but we'll still need to tie into the factory system to channel ATF to this additional cooler. Our engineer, Dave, plans to follow the same flow pattern as the FJ's cousin. First, the fluid will flow from the transmission to the cooler, then loop into the heat exchanger in the radiator's end tank, and finally, back into the transmission at the optimal temperature.

With the plan in place, our engineering team fabricated a fitment prototype to triple-check our work. While our 3D scanner and modeling software create a digital replica of the FJ's front end, we find that it's still imperative to test fit on the vehicle itself, especially when adding components to such a vital part of this platform.

A burnt-out transmission is one way to tarnish Toyota's tough reputation, especially when it happens to one of their most formidable off-roaders out on the trail. With our new transmission cooling plans in place, we're eager to get our first round of samples in the facility. So make sure that you stay tuned for the first look at our production sample coming soon!

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