Trans Temp Sensor Location

[Scottyg1]

I've read most of the threads concerning location. I really want to monitor the temp that the internals are seeing most of the time. I understand temp and its effect on fluid and I know the hot line gives you the hottest overall temp that the fluid is reaching. Now with that said, which location would provide the most accurate overall temps test port, hot line or pan ? I'll change the fluid accordlingly, but I'm more concerned about not exposing the internals to temps that will cause them to break down.

 

[ScottLewis]

Kind of like "elbows", everyone has an opinion about which is best. I've had both pan and cooling line sensors and both give you information about how hot the transmission is. I prefer to know quickly when it is producing heat that could lead to problems. That way I can modify my driving to cut it back. With the probe in the pan, you don't know about heat buildup until all the oil and transmission components have reached the target temperature. At that point it takes a lot longer to cool things down to better levels. It's just a matter of not letting it go that far.

Either way works, you just need to know what the gauge is telling you and act accordingly.



Dan

 

[klaybus]

Bill of DTT says hot line. So thats where I put mine FWIW.



Clay

 

[cerberusiam]

Internal temps are going run at or slightly above engine temps when fully warmed up and depending on load. The hot line temps are going to tell you whether or not you are building excess heat in the trans by the spikes you will see under load conditions. When your hot line temps start spiking and not dropping much below the highs you are heat soaking the trans.



There is not really a "good" place to monitor actual trans temps. The pan is a mixture of hot internal oil and cooled oil returning so what you will get is the cooler readings. The test port has no flow to it so it will always reflect a localized higher temp plus a probe in that port has a very good chance of causing trans damage.



Your best position is still the hot line, learning what causes the temp spikes, and addressing the source. You cannot do anything about heat soak once it is there except remove the load, but, there are things you can do to prevent the heating. IMO, you are much better off addressing the problem instead of monitoring the symptoms.

 

[Bertram65]

I have run with the probe in the rear test port and in the pan, they both read about the same with similar reaction times to changes in load and speed.

My trans runs about 160 empty on a really hot day with the coolant just under 200 and the oil temp at about 230, towing it may got up to 180 or 190 but rarely higher.

Reading the temp on the hot side of the cooler you have no idea if the trans is hot or at normal temp, only that the fluid is doing it's job by taking heat away from the trans.