[mj64car]

I want to finish installing my automatic transmisssion sending unit but have conflicting directions. Autometer says to measure the temp leaving the transmission and Ron Sessions in his book says to measure the temperature returing to the transmission. Which would be better? Why? Either would tell me what normal for that area would be and if it went up and how much.

[formulabird428]

I was confused about that myself. I can say, that it makes a HUGE difference (obviously).

I had one of those blue "block" adapters near the radiator, and the temp there was about 140F (at least I think, because the gauge never moved).

I installed the sensor in the pan, it's about 155F to 165F...hottest getting to 170F (30 minutes of idle traffic at Car Cruise)

My point? I'd honestly go for the pan. I think it's the most accurate and I'm sure others would agree.

[455_regal]

Id tap into one of the side pressure ports.

[Old Man Taylor]

I use the pan.

[67whitetrashbird]

For those using the pan, did your pan come tapped already or did you have to tap it your self?

[455_regal]

I was thinking the fluid in the pan is already cooled a bit, the case would show a more true reading of the internals.

[myckee]

Bruce Toelle of PTS has this to say about where to put the sensor and why. This is for a 2004R...the same reasoning is probably true for other trans as well, but I am not certain. :

The discharge or out line is converter discharge oil. It will tell you the temp of the converter discharge but NOT what the trans is seeing.
As for the temp bung in the pan, that can be what we call "stagnent" oil meaning, it is really not always in the circuit. By measuring at the return cooler line shows EXACTLY what the lube return circuit temp is and what the lubrication temp is.
Hope you follow this and if not, let me know and we will continue this discussion.
But, I hope this makes sense to all.
BTW: Our pans do have an 1/8th pipe plug in then for the drain, but to cheat and install easily you could put it there.

Bruce
WE4
www.PTSXTREME.com

[Old Man Taylor]

My pan had a boss for it but it did not come drilled and tapped. I had that done after I got it.

[RAIV55]

Personally I can oil in the cooler line not moving past the temp sensor more easily than stagnet oil the the pan.

Mine is in the pan. I have one digital temperature guage and a switch that is connected to sensors in the tranny pan, engine pan and for the coolant.

[Pontiac1976]

You can put it on the side of the trans on 350TH for sure.I had the tran shop put it there when I got the tran built. It's been there 13 yr's now I for get the exact place, but good reading there Driver side. I pretty sure the
400TH can do the same thing. as for the 200R4 & 700R4 have not looked in to them yet if it mounted there to.

[formulabird428]

I had to drill the hole, and then I went a step further and welded an aluminum bung in the pan. It's located on the slant part of the pan, rear passenger/backside. Works great! Out of the way, and I think the temp is quite accurate there.

[mzbk2l]

When I was testing transmissions, we (obviously) monitored the temp in several locations (to cooler at trans, from cooler at trans, cooler inlet, cooler outlet, sump temp, etc.).

We always looked for a max sump temp of 250 and a max converter out of 300 degrees F. Whether or not you choose to allow your temps to get this high, those numbers should give a rough idea of the temperature variation between sump temp and converter out temp.