What are your transmission temps?

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kossykoss

kossykoss

Joined
Nov 25, 2023
Threads
4
Messages
16
Location
California
Hey everyone. I’ve been using my ultra gauge to keep track of my transmission temps on my 2013 LX with the 6 speed AB60F. I’ve been seeing torque converter temps as high as in the 230s when accelerating up grades during cross country highway trips. Pan temps are normally around 185 - 195 matching my engine coolant temp. Highest I’ve seen my pan temp get to was around 203 degrees during a long gradual uphill. Ambient outside temps around 65 Fahrenheit. These temps are with the truck NOT towing anything. I’m on 33s with a front bumper and winch.

Just curious what temps everyone else is getting when they’re not towing anything. I’m considering keeping the transmission thermostat pinned open if it helps with the longevity of the box. Thanks all.
 
That thermostat is there to help the transmission fluid quickly reach its operating temp. Pinning it open might be as bad, or worse, than running the temps you currently see.

I'll let a SME chime in on your actual temps, but they don't seem bad to me.
 
lx200inAR said:
Threads on topic:

forum.ih8mud.com

At what transmission temperature should I be concerned when towing

forum.ih8mud.com forum.ih8mud.com

forum.ih8mud.com

Ultra-Gauge Blue

forum.ih8mud.com forum.ih8mud.com

I think there's a longer one as well, that maybe started because someone was going to add a cooler. Pretty sure the general consensus is the 200 trans cooler system is top notch. I doubt you will find many people recommending circumventing Toyota's design in this case.
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Thanks! I never stumbled upon those threads. Just a lot of threads talking about towing. I’ve read about tundra guys pinning the thermostat and reporting running up to 30 degrees cooler but I understand we have a different cooling setup in the 200. I recently had to replace a solenoid and flushed the entire trans so I just wanted to make sure my temps were solid after all that.
 
kossykoss said:
Hey everyone. I’ve been using my ultra gauge to keep track of my transmission temps on my 2013 LX with the 6 speed AB60F. I’ve been seeing torque converter temps as high as in the 230s when accelerating up grades during cross country highway trips. Pan temps are normally around 185 - 195 matching my engine coolant temp. Highest I’ve seen my pan temp get to was around 203 degrees during a long gradual uphill. Ambient outside temps around 65 Fahrenheit. These temps are with the truck NOT towing anything. I’m on 33s with a front bumper and winch.

Just curious what temps everyone else is getting when they’re not towing anything. I’m considering keeping the transmission thermostat pinned open if it helps with the longevity of the box. Thanks all.
Click to expand...

These temps are within normal from what I see without towing. I would say they reflect a good working cooling system and clean bill of health.

The biggest driver to heat in the transmission I see, towing or not towing, is HP input to the motor and torque converter unlocked. With almost 400hp on tap, it's easy to make things warm. The cooling system is robust and well up to it. Even in extreme use which is extended periods of peak output, gas pedal to the floor, in summer, and hauling a heavy load. I believe I've put it through the ringer in with all those at once and it still holds up. I did install an aux cooler, as I'm being mechanically sympathetic as I'm 1k over GCWR at 15,620 lb. Even then, I don't think an additional aux cooler was completely necessary and really only for the most extreme users.

Pinning the thermostat would be misguided. It would provide zero additional BTU cooling capacity. While ruining the efficiency and refinement it provides in warming up the tranny quickly.
 
kossykoss said:
Thanks! I never stumbled upon those threads. Just a lot of threads talking about towing. I’ve read about tundra guys pinning the thermostat and reporting running up to 30 degrees cooler but I understand we have a different cooling setup in the 200. I recently had to replace a solenoid and flushed the entire trans so I just wanted to make sure my temps were solid after all that.
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No worries...also just from a "how things work" standpoint. Pinning open a thermostat should not affect running temps. Once the thermostat is open (98% of driving) then your essentially in the same position as having a pinned open thermostat. So the only way pinning it open could make a difference is if the engine is never reaching operating temp somehow, or if the non-pinned thermostat is faulty and blocking flow when it should be allowing it.

edit: as always @TeCKis300 beat me to it....
 
For the record due to the front tires being so exposed a front bumper is basically like pulling a small trailer any time the vehicle is moving at more than neighborhood speeds.

Also I agree with Willie, Teckis, and lx200AR. More harm than help.
 
Thanks for the input everyone. Glad my transmission isn’t abnormally hot. The thermostat will NOT be getting pinned. And I never really thought about the front bumper like that but it totally makes sense. I wonder if I should be doing diff and xfer case fluid at eariler intervals because of the added weight and drag? 🤔 I’ll do some research. Thanks again!
 
kossykoss said:
Thanks for the input everyone. Glad my transmission isn’t abnormally hot. The thermostat will NOT be getting pinned. And I never really thought about the front bumper like that but it totally makes sense. I wonder if I should be doing diff and xfer case fluid at eariler intervals because of the added weight and drag? 🤔 I’ll do some research. Thanks again!
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Stick with the severe duty recommendations in the manual and you’ll have a very long life out of that rig.
 
Found this thread because I was curious if any 200s run their thermostat pinned.

After my second 20k-interval transmission drain-and-fill in my Tundra, I left the thermostat pinned open. I've been watching temps. It is amazing to me how much cooler it runs. It has lowered my transmission's temperature significantly. I see around 165-175ºF at the pan now. I did push the truck hard on a road trip last week. We were fully loaded, not towing, cruising at 85 and keeping up with the fastest traffic. Prior to pinning, I would normally see 205-210ºF at the pan and well into the 230s at the TC on long grades with an unlocked torque converter.

My experience is the same as many others on the Tundra forum report: pinning the thermostat results in cooler temperatures, even when you're working hard. It's counter-intuitive, as you would think once you hit 185-195, the thermostat is going to open anyway. But I don't think it opens anywhere near as much as when it's pinned. While pinned on this last road trip, I tried to keep my TC unlocked for as long as possible, and I got the pan up into the low 190s, but once I settled back down to 70-75mph, it dropped back to 170ºF. Torque converter still gets over 200ºF on long grades but falls quickly back to pan temps.

What exactly is the downside to running 30+ºF cooler? Especially if you're towing at or over your limit? Our two old Suburbans (good riddance) gave us loads of problems but never had transmission issues, and they ran in the 150-160ºF range. Our 570 runs hotter than our Tundra.

I'm thinking about pinning it open, too, next time I get under it.
 
LX Cruiser said:
Found this thread because I was curious if any 200s run their thermostat pinned.

After my second 20k-interval transmission drain-and-fill in my Tundra, I left the thermostat pinned open. I've been watching temps. It is amazing to me how much cooler it runs. It has lowered my transmission's temperature significantly. I see around 165-175ºF at the pan now. I did push the truck hard on a road trip last week. We were fully loaded, not towing, cruising at 85 and keeping up with the fastest traffic. Prior to pinning, I would normally see 205-210ºF at the pan and well into the 230s at the TC on long grades with an unlocked torque converter.

My experience is the same as many others on the Tundra forum report: pinning the thermostat results in cooler temperatures, even when you're working hard. It's counter-intuitive, as you would think once you hit 185-195, the thermostat is going to open anyway. But I don't think it opens anywhere near as much as when it's pinned. While pinned on this last road trip, I tried to keep my TC unlocked for as long as possible, and I got the pan up into the low 190s, but once I settled back down to 70-75mph, it dropped back to 170ºF. Torque converter still gets over 200ºF on long grades but falls quickly back to pan temps.

What exactly is the downside to running 30+ºF cooler? Especially if you're towing at or over your limit? Our two old Suburbans (good riddance) gave us loads of problems but never had transmission issues, and they ran in the 150-160ºF range. Our 570 runs hotter than our Tundra.

I'm thinking about pinning it open, too, next time I get under it.
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When thinking about large operational changes like this I try to ask myself.. why didn't Toyota just do that in the first place?

For engine temps there is an efficiency and power benefit to not running too cold. For transmissions... why wouldn't they want it cooler if it were that easy?

I'd stress getting an answer to your question "What exactly is the downside to running 30+F cooler?"

I do believe toyota uses the in-radiator heat exchanger to help warm the transmission fluid more quickly when it's cold.. I think this mod wouldn't prevent that.
 
^Yup to that.

It's about modulating the transmission temperature across the spectrum of use cases. Cooler is not better.

As we're approaching winter, a pinned thermostat is going to create unnecessary compromises.
 
bloc said:
When thinking about large operational changes like this I try to ask myself.. why didn't Toyota just do that in the first place?
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Because Toyota set a standard of use that we are exceeding, some of us by a pretty wide margin.
bloc said:
I do believe toyota uses the in-radiator heat exchanger to help warm the transmission fluid more quickly when it's cold.. I think this mod wouldn't prevent that.
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Counter-intuitively, the fully pinned-open thermostat seems to outwork that warmer.
TeCKis300 said:
It's about modulating the transmission temperature across the spectrum of use cases. Cooler is not better.

As we're approaching winter, a pinned thermostat is going to create unnecessary compromises.
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Agreed. I think it makes sense for towing season, probably not for the winter.
 
LX Cruiser said:
Because Toyota set a standard of use that we are exceeding, some of us by a pretty wide margin.
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Anywhere in America? Compared to how they are used in other parts of the world?
 
bloc said:
Anywhere in America? Compared to how they are used in other parts of the world?
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Are they rated differently elsewhere? I know Aussies can get a certified higher GVM rating with upgraded shocks, brakes, etc. But I am not aware that Toyota rates the same vehicle for more payload or a higher GCWR.

Regardless, we see people exceed Toyota's ratings all the time on this forum. If I were towing an 8k trailer and my transmission stayed well above 200ºF for sustained periods of time (the towing thread is full of temps in the 230s-240s), I would pin the thermostat and give the radiator up front a prayer of controlling those temps.

Didn't one guy who tows well above the door jamb numbers just lose his transmission?

My opinion here is colored by the impression that, having spent a lot of time on both forums, the 200/570 has more temp-related issues than the Tundra/Sequoia.

Tundras and Sequoias don't vent boiling fuel, and for the production numbers they really don't seem to have as many intake valley coolant leaks.
 
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