Finally added a transmission cooler. Felt my transmission was struggling last summer with my 33” tires and roof top tent (which I recently upgraded).
My goal was a clean, OEM look. I
really wanted to avoid ugly brackets. I’m very happy how the install turned out.
For my install, I used a Derale 13503 cooler and bought and extra 4' of transmission line (glad I did this). Specifically, I bought Hayden 106 line off Amazon. Also used another ~.25 quarts of ATF to top off the fluid.
Tips for the install:
-This is an in-series install. Not a bypass (not recommended based on my research). Transmission cooler comes after the radiator, and the output from the cooler goes back to the transmission.
-Bottom inlet is the input and top is the output to minimize changes an air bubble gets stuck.
-Tube and fin coolers are the least efficient, then plate and fin (what I bought), then stacked plate
-As far as I understand, you cannot overcool transmission fluid.
-I only needed to drill one hole and install one Rivnut (I used an M8 because I didn't have an M6 Rivnut. Bothers my OCD but whatever.) Other two mounting points used already threaded holes. See my pic. I needed a 30 mm spacer for one of the mounting points (see pic)
-When you add ATF and run the ATF fluid temperature process, expect to wait MUCH longer. I waited 45 minutes for the temp to come up to “measuring temp.” Towards the end of the process, I realized I could speed up the process by restricting flow to the transmission cooler with a fancy, high tech piece of cardboard.
-Took about 3 hours for the entire process
Some helpful links I referenced
Proper tune routing instructions:
2006 4.0L Transmission cooler installation, with some pics. - Toyota 120 Platforms Forum
Helpful general DIY
How To: 4th Gen V6 Radiator Replacement/Tranny Cooler Install | Toyota 4Runner Forum [4Runners.com]
How to put car in ATF Temp Check mode
How to Drain/Refill Automatic Transmission | Tacoma World
In the process:
Close-up of mounted cooler:
40 mm Spacer: