3rd gen Transmission Cooler Upgrade

Higher temp at tc2 if I recall correctly.

 

So just for the heck of it - I decided to take the radiator cooler out of the mix to see what the temps would be. It was easy by just switching over one hose connection. Oddly enough - on a pretty good drive at higher speeds (70mph) - it raised the temps approx. 20 degrees (to 170 from 150). Don't ask me to explain that as I would have thought the opposite getting the fluid out of almost 200 degree coolant.

 

Now you have me confused here. The factory trans. cooler goes into the radiator and uses the "anti freeze" around the coils to cool the trans fluid. Are you actually implying that I ran the anti freeze into the transmission ??? That's pretty funny stuff. My main goal here is to eventually do away with the factory cooler, cause of the problems other manufactures have had with internal leaks causing a mixture of the two fluids (that would be bad). But to keep it at aprox. 150 degrees - I'm now thinking to add a second external cooler cause there is still plenty of room. Sorry if I confused you. Regards Scott

 

Is there a specific metric threshold, like transmission fluid temperature, that warrants this upgrade? If so, what sustained fluid temperature makes this the correct decision?

 

I go through the mountains of Western Pa. with a heavy trailer and like to keep the trans. temps. at a minimum. I feel if I can sustain 150 degrees or so empty - then with the trailer on it should get it up to 200 or even 225 degrees. This is a bit of experiment, but I'm also looking to eventually not have the factory cooler in the mix. But with Toyota doing away with the external cooler - I strongly feel that something is for sure needed for towing. Just my thoughts ?? I am not selling myself as an expert of any kind here. Regards Scott

 

Toyota did away with the stand alone external cooler (in 2020 iirc). The ATF is routed through the radiator for cooling.

 

That really surprised me !!

 

All of the third gens run the ATF through the radiator and ones with a tow package also have a secondary cooler. I've never seen an auto car didn't in same way use engine coolant to help cool the trans.

 

Even tow package equipped Tacomas no long have the secondary cooler. Toyota completely did away with them sometime in 2020. Tundras lost them too in fact.

 

Correct. Should have added the extra cooler was deleted somewhere in the 20 model run. Point was that every auto car uses engine coolant to help warm and cool the trans.

 

Theoretically only to "cool" it on the Tacoma, because there's a thermostat.

 

my 2016 OR which has the oem tow package cooler and an additional parallel cooler runs sub 195 always when towing over passes 11,000 ft plus. Guess that makes it worth at least $10K more than the 2020 plus models which don't have these coolers! The Supercharger will cost you more!

 

How's your SC and trans temps?

 

• as noted. just came back 350 mile round trip camping trip -towing 100% of the time with max elevation 12,129 ft pass - never once over 190. Yes speed was lower for tight twisty roads - 40 mph max but no issues - locked to s 4 max. averaged 17 mpg round trip. SC on passing lanes simply amazing - even Ford 6.7 towing camper could not keep up.

 

bumping this thread..

does anyone know the size of the cooler line fittings from the tranmission as seen in the top picture? My goal is to add a manifold that accommodates a 1/8-27 temperature sender for a trans fluid gauge.

 

if you're talking about the metal lines, no i don't sorry.

if you're talking about the rubber hose, i used 3/8ths no problem

 

Why would you do that when you can track trans temp using a ScanGauge XGauge? Note: speed limit is 80 in ID.

Also, if you did that you would be measuring temps at the cooler. Seems to me the better place for that is in the pan, which, ironically, is where the factory sensor is...

 

This thread inspired me to build this setup. Installed in series using a high efficiency cooler (11 fins total). Stays in the 190's with 3k trailer on modest grades.

I'm planning on drafting a write up in my build thread eventually..

 

I've whined about this before but when is ScanGauge going to produce a modern day readout screen as opposed to the Atari Pong & Space Invaders game era technology? It's 20 frikkin 22 for crimeney sake!

 

good question! I have been monitoring parameters using the Torque and Fusion APPS for several years now. Recently though, on my last two trips on the trail. I been having some coolant system issues that suggests a restriction in the radiator. So, I am going to be swapping in a Mishimoto double row radiator and a aftermarket trans cooler with an electric fan. And at the same time, I'm installing mechanical gauges for coolant and trans temps monitoring. The original plan is to use the trans temp gauge to activate/deactivate the fan relay.. If I'm able to install a manifold on the out going cooler line on the transmission side. Ultimately, I will have a electric fan on the radiator as well.