3rd gen Transmission Cooler Upgrade

I guess I didn't think I needed to determine which line was the high pressure line. Pressure wasn't the issue - oil temperature was.
It only makes sense that you would want the heat carried away from the trans and be returned cooler.
That what happens with just the in-rad/trans oil cooler.
It makes sense that the line carrying the heated fluid to be cooled, would be hotter. Then, when put through the cooling of the radiator, be cooler and be the return line.
By adding the Hayden, I only inserted an additional cooling device.
I doubly checked the lines, blowing thru them, for free flow and couldn't feel any decrease in pressure - a minimum of 4"-5" bends in the lines.

I've had this set up for a year now. Driven in 110F in Phoenix, AZ,. All good. Say max freeway trans oil temp 175F.

In winter, I put a 3.5" piece of cardboard on the Hayden, held on with a bungee cord. Added about 8F. From 145F to 155F trans oil temp at 65F driving temp.

Not advocating anything. Just sharing my experience. People have to make their own decisions on this issue and set ups.

 

Got it, just asking. Not saying I’m right or wrong, curious to find out what others find. To me figuring out the high pressure line determines the flow.

My light for hot trans fluid came on after going to bigger tires while climbing twice. I decided to flush, external cooler and monitor the temp. I flushed with Amsoil, using a moshimoto cooler, and have a scan gauge now. My 22 was overfilled by factory. I never go over 205 anymore and my cooler is wired to a switch which is usually off. I decided not to pin the tstat either. I’m in California where it’s been 110. Flushing the excess fluid seems like it fixed my problem.

 

Its always a good idea to monitor the trans temps using Scangauge, Ultragauge, or using the Torque Pro OBD app to help determine if you need an additional cooler or not. Things like driving in the sand, mountain passes (onroad or offroad), skid plates and bumpers, towing, oversized tires, all play a huge factor along with ambient temp. Anything over 220 deg F is getting too hot. By the time the light comes on at 305 deg F you've started damaging the trans and 100% cooked the fluid.

It was fascinating watching my gauges when driving to Colorado to do some offroading and mountain passes. Shifting or unlocking the torque converter generally results in a spike in temperature. With my Hayden cooler on 39" tires in my FJ I never saw over 210 degrees F, I think that happened once while driving in low range up an easy offroad trail up over 12,000 ft elevation without stopping for a break. Most of the time the temps never exceeded 195 deg F.

 

Understood!
Good to know that there is another person who understands HEAT !!!!.

I decided to PIN when I read some of the threads here concerning pros and cons of pinning.

For winter, I just cardboarded the Hayden about 40% to get a 8-10F temp increase

I didn't like the idea of always getting the trans fluid up to 185F or 195F before the T-stat shunted the oil to the rad. Looking at the oil Temp/trans Life charts and about 20F decrease in oil temp and trans life extension....

Even in winter, it gets up to 75F and maybe 3 nights/ year it gets below 32F.

 

I use Torque Pro on my tablet with an OBD thingy.

 

Oh ! ... in winter I cardboard the Hayden ..... NOT summer of course !!

 

The warning light isn't till 305*??!? I knew it was set too high, but that's nuts...

 

Is the standard pay version of Torque Pro sufficient or do we need the Toyota add on? The reason I ask is because it won't let me download the "Advanced EX for Toyota" because my version of Android is too new.

 

Trans thermostat pinned or unpinned?
I assume pinned, as temps are below 187

 

Trans thermostat pinned or unpinned?
I assume unpinned, as temps are below 187

T-Stat PINNED.
Here's the closest screen shot I could get. 203 miles driven, 3hrs 38min driving, at 106F outside, 203 coolant temp, with 173F in the PAN and 176F TC at about 1:23 PM. Car at freeway rest stop. Coolant seems to range between 185F and 205F on any one trip.

 

I use standard pay version Torque Pro - not the Advanced mentioned or Torque Lite.

 

Thanks. I thought maybe I needed that plug in I mentioned. I'll grab the pay version now and hunt down the PID's I need. Thanks!

 

I use the Torque Pro app with the below scanner with the attached PIDS.
Tacoma 2021 DCLB v6 automatic trans, pinned external cooler.


OBD2 Mode and PID: 221627
Long Name: Transmission Fluid Pan Temperature
Short Name: TF1 (pan)
Minimum Value: -40
Maximum Value: 350
Scale Factor: x1 (do not change)
Unit Type: F
Equation: (A*459/255)+(B*1.6/255)-40
OBD Header: 701
Diagnostic start command: (leave blank)
Diagnostic stop command: (leave blank) automatic trans
Overrides PID: Does not override any PID

OBD2 Mode and PID: 221628
Long Name: Transmission Fluid Post-Converter Temperature
Short Name: TF2 (conv)
Minimum Value: -40
Maximum Value: 350
Scale Factor: x1 (do not change)
Unit Type: F
Equation: (A*459/255)+(B*1.6/255)-40
OBD Header: 701
Diagnostic start command: (leave blank)
Diagnostic stop command: (leave blank)
Overrides PID: Does not override any PID

Some results with pinned external cooler. Notice the TF1 and 2 results and the Ambient Outside Temp, speed and mileage of the trip. Truck was packed for camping say, 600 lbs including me on mainly flat freeway driving.

 

Thanks. Found the PID info and added them. The app gave the impression I needed that add on even though I didn't. Truck is at home so I'll test it when I get home tonight. Only thing I'm struggling with is despite my changing settings to display in *F the engine coolant is still in *C but I read you may have to connect to the car so get the new setting to take.

 

So apparently you need to connect to the OBD2 dongle in the truck to get the ECT reading to switch to Fahrenheit. All working 100% now.

 

Not to go off topic too much but I saw 208 coolant temp after pulling off the interstate and sitting at a red light for a few minutes. 195 traveling down the interstate (mid 70s ambient Temp). Thought that was a little high

 

Just adding some information for anyone interested. I just came back after towing my 3500 pound camper 5400 miles over the Rockies and around the top of Lake Superior (serious hills). My 2020 has no auxiliary transmission cooler. Monitored via scanguage 3, I can confirm that there is no need for an auxiliary cooler for that configuration. Never saw a worrisome temperature and the truck was working on some of those hills.

 

What temp did you see?

 

What PIDs were you monitoring? What gear were you in and at what RPM while going up the steep grades?

 

What I've noticed is that when you get off the freeway and sit at a light, Pan and Converter temps increase 8 -12degrees F.