Where to put trans temp sending unit

[terry5357]

I did a search and found that there is a place where the Ford service guys can check tranny line pressure guage to monitor line pressure, is this a place where I can put a temp sending unit to monitor trans temps.

 

[Liberty911]

In the pan. Probably not where you wanted to go, but provides the most accurate readings.

 

[limelight]

Trans temp sensor should go in the pan.

 

[tmcolegr]

I put mine in every location possible (cooler inlet, cooler outlet, pressure taps) and finally broke down and put it in the pan.

 

[94tbird]

i was told by FB Performance the Pan does NOT give proper readings as it is not the hottest point. i forget if they said in the line from the trans to the cooler as that was the hottest point or in the return line between the cooler and the trans. ill find out for sure on Wednesday when i drop the car off

 

[bigwilly43729]

i was told by FB Performance the Pan does NOT give proper readings as it is not the hottest point. i forget if they said in the line from the trans to the cooler as that was the hottest point or in the return line between the cooler and the trans. ill find out for sure on Wednesday when i drop the car off

I ended up putting mine in the pan, but I tried this method initially. Let's just say it was a bit messy and not really worth the effort IMO.

I'd think the line to the cooler would be the hotter of the two lines. If I were to do try it this way, I'd put it (the sending unit) right where the rubber hose meets the steel hose.

 

[limelight]

All factory transmissions that I am aware of put the temp sensor in the pan. What matters is the temperature of the fluid that is entering the filter pickup. This will tell you if the trans cooler is doing it's job. I have never seen any temp sensors in the cooler line before the cooler.

 

[07 Boss]

Are all tranny temp sensors the same? I am putting a new pan in this week and I was going to have them set me up with a spot to put the sending unit. If I tell them to drill and plug a spot for the future, do I have to specify a certain size, or do all the different brands use the same size sending unit?

Edit; probably going to go with Nexus guages.

 

[antonio1988]

Good post, I was just about to ask about this. My tranny grenaded and is being rebuilt because of too much heat

 

[Liberty911]

If I tell them to drill and plug a spot for the future, do I have to specify a certain size, or do all the different brands use the same size sending unit?

Edit; probably going to go with Nexus guages.

I don't know about sending units for Nexus, but 1/8" NPT should allow you to use several sending units. Are you going with an aftermarket pan?

 

[05stroker]

Put a 3/8 in there . You can always use a fitting to get to a 1/8 but you cant make a small hole bigger.(Without redrilling)

 

[Natural1]

I would consider a transmission cooler feed tap, the best location. It gives a reading straight out of the heart of the transmission and represents the actual transmission temperature. If you have a thermostatically controlled (fan equipped) cooler, it won't be too hard to figure out. If the fluid hitting this sensor is too hot, then it was too hot to begin with and the trans cooler is undersized.

 

[07 Boss]

I don't know about sending units for Nexus, but 1/8" NPT should allow you to use several sending units. Are you going with an aftermarket pan?

I went with a deeper PA pan. Wanted to give it a greater capacity (4 qts.) to help keep temps down instead of a bigger cooler. Just plan on running a 3000 stall converter and not a whole bunch of track time. Plus, this one came with the tranny dipstick/fill tube that Ford gorgot to put in our cars.

I would consider a transmission cooler feed tap, the best location. It gives a reading straight out of the heart of the transmission and represents the actual transmission temperature. If you have a thermostatically controlled (fan equipped) cooler, it won't be too hard to figure out. If the fluid hitting this sensor is too hot, then it was too hot to begin with and the trans cooler is undersized.

I thought about that too and will decide exactly where to put it when the time comes. Just want to get this converter and tranny pan in for now. Just didn't want to be yanking it back off later if I decided to put it in the pan. Call me lazy....I call it efficient.



So I have a range of 1/4 of an inch here. Anyone now what size the sensor hole needs to be?

 

[terry5357]

I went with a deeper PA pan. Wanted to give it a greater capacity (4 qts.) to help keep temps down instead of a bigger cooler. Just plan on running a 3000 stall converter and not a whole bunch of track time. Plus, this one came with the tranny dipstick/fill tube that Ford gorgot to put in our cars.




I thought about that too and will decide exactly where to put it when the time comes. Just want to get this converter and tranny pan in for now. Just didn't want to be yanking it back off later if I decided to put it in the pan. Call me lazy....I call it efficient.





So I have a range of 1/4 of an inch here. Anyone now what size the sensor hole needs to be?

I had a B&M tranny cooler installed in line with the OEM cooler. I guess if I were to install a gauge I would use something like like a block that is tapped on each end and somewhere in the middle for the sending unit to hang in to, and I guess I should put this on the "inlet side" of the OEM cooler so I know what temp the trans is.......correct?

 

[Natural1]

I guess I should put this on the "inlet side" of the OEM cooler so I know what temp the trans is.......correct?

That's how mine will be.

 

[antonio1988]

I had a B&M tranny cooler installed in line with the OEM cooler. I guess if I were to install a gauge I would use something like like a block that is tapped on each end and somewhere in the middle for the sending unit to hang in to, and I guess I should put this on the "inlet side" of the OEM cooler so I know what temp the trans is.......correct?

Is this the one you bought? Is the installation something I could possibly do myself?

 

[07 Boss]

Well here is a question to you guys that think it's better to put it in the feed line to the cooler. I understand the logic of it but here is my query. If you were doing an engine oil temp sensor where would you put it and why? The only place I have ever put one is in the pan or in one of those sandwich plates. If you follow the same logic you should put it into an oil passage, or where the oil drains back into the pan, to get an accurate reading, right? Well how come nobody has done it that way? So if the pan is good enough for engine oil temp, why would it be any different for using the pan for tranny fluid temp?


And again, what size should I tap the pan, 1/8" looks like the right size, just looking for confirmation?

 

[Natural1]

Well here is a question to you guys that think it's better to put it in the feed line to the cooler. I understand the logic of it but here is my query. If you were doing an engine oil temp sensor where would you put it and why? The only place I have ever put one is in the pan or in one of those sandwich plates. If you follow the same logic you should put it into an oil passage, or where the oil drains back into the pan, to get an accurate reading, right? Well how come nobody has done it that way? So if the pan is good enough for engine oil temp, why would it be any different for using the pan for tranny fluid temp?


And again, what size should I tap the pan, 1/8" looks like the right size, just looking for confirmation?

I like your thinking, but here is mine... In the transmission, cool fluid is pulled from the pan and used to actuate clutches, bands, etc. As the fluid runs through the transmission, some of it is pumped to the cooler. The fluid that is in the pan does not always represent the true temperature, because the cooler empties back into the pan. In an engine the fluid drains back to the pan hot from the engine, so it represents the actual oil temperature better than any other area, with the exception of [insert random port here], at the end of the engine lube circuit.

 

[07 Boss]

I like your thinking, but here is mine... In the transmission, cool fluid is pulled from the pan and used to actuate clutches, bands, etc. As the fluid runs through the transmission, some of it is pumped to the cooler. The fluid that is in the pan does not always represent the true temperature, because the cooler empties back into the pan. In an engine the fluid drains back to the pan hot from the engine, so it represents the actual oil temperature better than any other area, with the exception of [insert random port here], at the end of the engine lube circuit.

I did not know that. And thank you for enlightening me, and for your comliment.

 

[Natural1]

The transmission also dumps excess fluid into the pan, as an engine does but the pump is circulating fluid from the pan, converter and other areas that get pumped to the cooler. Does it make a real big difference? Probably not much, unless you are on the ragged edge as far as your temperature goes, running it at the track often or have a transbrake. If 10-20 deg (10% of the scale) was important to me, then yes I would rethink my probe location. I also read about people running 200+ degree trans temperatures and with a correctly sized cooler, it should be much lower. You really want to be at or around 175 deg. Anything over 200 deg starts to slowly (or rapidly if the temp is higher) break down the fluid and varnish parts, causing clutch slippage and valves to fail. The seals in the transmission are either cast rings, teflon, or buna rubber. The cast rings seal off different components (stator support/tailshaft), the teflon is used on shaft seals between drums, and the buna rubber is used on piston seals and case sealing. The piston seals are probably the most easily affected by heat and they are only thousandths of inches from the clutches and steels, where a great deal of heat is generated. Let's also not forget that the torque converter has a clutch with a piston and seals in it as well. Much heat is generated here also.