Advice for location of Trans. Temp Sensor

[outrun]

My assumed suspects are the pan and cooler lines. However what part would be ideal and why? My reasoning is that the OUT line may contain the hottest temperatures. The IN line may be coolest. The pan may be an average or even a biased due to stagnation? Ideally, I would think somewhere internally (valve body, torque convertor) would be the best picture of the internal system ... but from an aftermarket standpoint it is not cost effective and a borderline threat to OE reliability to play around with those critical components. So far the easiest idea is to buy an aftermarket pan with a drain plug and put the sensor there.

Thanks.

 

[sdan27]

I think it would probably be the easiest to install off the oil pan itself but I think it would be most effective to put it on the line going to the cooler. That seems like it would be where you would get your hottest temperatures and could most adversely affect the fluid. I wonder if you installed on the pan rather than the cooler line, you would have to be concerned at a lower temperature reading than if you installed on the cooler line.

 

[The_Jeff]

Remember rad coolant varies widely in temp and the temp of ATF returning could be much cooler or even slightly warmer than when it left! I would go with the "to cooler" line.

 

[DieselTech]

What make model and year? many have sender ports on them for a temp gauge

 

[Gary Allan]

I go with the pan. ATF decays on a time weighted average at temp. All other temps will be transient. The pan gives you the "insult reserve" quotient of the system as stressed.

I had a much better sounding rationale for it somewhere back in my history ..but essentially you're either reading peaks or lows with cooler line senders/sensors. If you have both, it's great for determining your cooling efficiency. The pan will read the result of that product on how it impacts what the trans is seeing from the sump.

It's not like you need to know if your cam is seeing 250F oil temp with a sump that stays calm and cool @ 212F. There's no harm or benefit to the rad cooler from the ATF other than giving it a purpose.

 

[slammds15]

The cooler return line will give you a more accurate reading and let you know over all cooler efficiency. This way you will know if the cooler is even capable of functioning properly in your application. The pan would be suitable as well but would give you a biased/less accurate reading. If the oil is cooled down to an acceptable temp obviously everything is doing its job. The oil (correct me if I'm wrong) comes directly out of the converter so to speak and goes straight to the cooler. Your converter is the source at which at most of the heat is created.

http://www.bmracing.com/bmracing/installation_instruction/9500048-08.pdf

http://www.tciauto.com/Products/Instructions/instructions/801000.pdf

 

[slammds15]

B & M makes an excellent kit which is relatively cheap and easy to install.

http://www.bmracing.com/PRODUCTS/Cooler-...-kit-white-face

http://www.bmracing.com/PRODUCTS/Cooler-Accessories/Transmission-temperature-gauge-kit

 

[mechtech2]

The return line could read 20 below zero, but does not tell what is happening in the transmission. [not a likely scenario, but you get my point]

I would want to know what the hottest temp is. That would be the cooler outlet line.

But a sensor in the pan is quite useful too. You will get to know what is normal for your car. Maybe with a heavy load on a hill, you will have warning to pull over to let it cool.

 

[slammds15]

the outlet temp would be ok if you wanted to know how hot the oil was when exiting the torque converter. It wouldn't give you an accurate reading as to what the transmission was operating at.

 

[mechanicx]

I agree the return line or pan would probably give you the better estimation of what the AT operational parts are seeing in fluid tempature, and would probably be closer to where the OEM temp would read. the cooler out line is going to be some temp above that but what really matters is how hot the average fluid temp is getting and the pan would tell you that.

 

[mechtech2]

Why would you not want to know the hottest temperature?
That is the key. The localized heat can puke a localized amount of fluid.

 

[mechanicx]

I would say because the pan temp and the hottest temp coming out of the transmission to cooler line would have some correlation. If the highest temp was too high then the pan temperature would be too high as well.