Those with a ScanGauge. What's your typical transmission temperature?

I pull a 4500 lb travel trailer with my Tacoma. I also have a scan guage. I installed a

$185 Derale 52506 25 Row Core Stacked Plate Cooler Kit , Black

Derale 52506 and got a solid 30 degree drop in transmission temperature. I pulled my camper 100 miles last week in 100 degree outside temp through some steep hills and my temp never got over 168. Before It would reach 210 sometimes in heavy stop and go traffic. The derale stacked plate Derale 52506 has a cooling rating of 46,000 btu's per hour, the highest cooling rating you can get to fit in the available space you have. All I had to do to make room for it was move the horns to the center brace and did not have to change the wiring.

 

I installed a B&M 70264. Larger than stock but not as large as the Hayden installed by @tacoma16. Like him, I used the stock mounting location with some minor adjustments. You'll need to relocate your horns if you go this route.

Running around town without the trailer I was seeing temps in the 160 range. Towing the camper 6 hours each direction in 90+ heat the transmission seemed to hover in the 190-200 range most of the time, peaking at 235 during the two biggest hill climbs.

If you decide to do this, get a couple quarts of transmission fluid as well. You may only use one quart but (for me, anyway) it's better to have the extra quart and not need it than the other way around. There are how-tos on this site that explain how to check and fill - easy, 10 minute job.

...and as JRod said, NEVER TOW IN OVERDRIVE!

Good luck!

 

Probably not something I would go through the trouble of adding. The trans can handle the AT fluid being low temp, since that's how it starts out the day every day.

Toyota actually wants the fluid to run at a certain temp so that it ensures a certain level of efficiency, but this temp as we've seen puts you well into the 175-180 range where towing or hauling can get you up above 200. For them, it's all about gas mileage since they don't have to pay for a transmission replacement at 100K.

However, one trend over time is that the auto manufacturers have been spec'ing trans fluids that have much lower viscosity to improve MPG ratings (sort of like how a lot of cars are starting to use 20 weight oils).

 

The highest I have seen mine go was 205 briefly with a load going up a mountain pass on the highway. Typically see between 160 and 180 during hot weather.

 

Based on my research, a cool transmission is a happy transmission. Plus with all the added weight and tires I figured cooler than hotter like you said.

 

The temps get easily get over 200 in 4 wheel drive and even hotter in 4 low.

 

I've got an ultra gauge. Usually about 140 F.

 

I put the Durale 52506 in my 2015 ACOR today. Haven't hooked the trailer up yet, but it seems to run a pretty steady 135-145 on my Ultra Gauge running around town in 80 degree weather. It would frequently creep up to 200 before at a stop light, somebody should come up with a bullet proof setup for electric fans. The install looks pretty identical to Scottfarm's, took a couple of hours, and most of that was trying to decide what I wanted the brackets to look like. I ended up using a little more than a quart of new fluid, had to open the 2nd bottle (buy 2!) and put another 6 or 8 pumps in out of that one. The hot exhaust piping is a bit of a bear, but other than with the right tools it's easy.