normal transmission pan temperatures

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What are normal transmission temperatures when the probe is in the pan? I've heard 80 degrees above ambient temp. Mine are around 60 degrees above ambient temps on the highway and 80 or so above ambient when sitting in traffic. Are these normal? Same a little bit cold.
 
it totally varies with the vehicle.

My tundra never breaks 100F winter, and in normal driving never over 125F summer. On drives over an hour, about 150-160f summer. If I'm towing heavy, it gets right up to 160 and rarely goes over. there's a thermostatically-controlled cooler that seems to open around 160.

In our T&C, "fully warmed up" needs an hour to achieve. It might reach 120-140F in the winter driven hard. In the summer-- 160F a/c off, 180-210F a/c on with momentary peaks of 225.

these are both from discrete gauges.
 
I haven't figured out yet how to get pan temp on mine; the xguage for my Scanguage refused to return data. I do seem to have convertor outlet temp, which I wonder if it has almost as much importance: pan temp is going to determine clutch life, while convertor outlet determines fluid life. IOW, hot fluid on the clutches may or may not be good, but peak fluid temps will impact fluid lifetime.
 
I think I might have found the issue--I went out at lunchtime, and checked, added a new one too; neither worked. Afterwards for some reason I double checked what I wrote down--and I think I might have missed a number. The two ATF codes are really similar, but there is a one digit diff in TXD's which I bet I overlooked. Will update when I go home tonight.

Using the 2010+ codes from here:
https://www.scangauge.com/support/x-gauge/toyota-specific/
The first code TXD 07E021D9 does not work for me, but TXD 07E02182 does, and appears to be convertor outlet. TXD 07E12182 is not working--but I bet I entered it as 07E02182. Or I hope I did.
 
Nope, refuses to read that second sensor.

I'm tempted to hack up a gimmick: just find an LM35 temp sensor, and somehow affix to the side of the pan. It'll be the temp of the outside of the pan, not the temp of the fluid inside the pan; but may be close enough. I don't feel like draining out fluid I put in 2k ago for a sensor that fits in a bolt. [Of course, I'm not sure I really need to do anything, this would be purely academic.]

My temps (convertor outlet, remember) generally rise to water temp, unless if I get onto the highway quickly (or in cold temps), around 185-190F, depending upon time of year. It likes to stay there, but any amount of unlocked convertor usage will rise fluid temps. I have not see anything higher than 230F, but I haven't towed yet either.
 
Originally Posted By: motor_oil_madman
What are normal transmission temperatures when the probe is in the pan? I've heard 80 degrees above ambient temp. Mine are around 60 degrees above ambient temps on the highway and 80 or so above ambient when sitting in traffic. Are these normal? Same a little bit cold.


There is no such thing as average sump temperatures so the question is not a valid question.

Engine horsepower, torque, vehicle weight, and transmission design deterrmines temperatures.

The median sump temperature taken over many many vehicles at many temperatures is 205F.

For a vehicle with an engine producing 29,000 ft-lbs of energy,
clutch surface temperatures can reach as high as 600F for 3.5 seconds after shifting. The bulk oil circulating carries away much of this heat of course.
 
Previous statement above should say:

Quote:
Engine horsepower, torque, vehicle weight, and transmission design determines temperatures.

The median sump temperature taken over many many vehicles at many different driving conditions and ambient temperatures is 205F.

For a vehicle with an engine producing 29,000 ft-lbs of energy, clutch surface temperatures can reach as high as 600F for at least 3.5 seconds after shifting. The circulating fluid carries away much of this heat to the sump.
 
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