CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

tranny temp sensor placement?

jms

1/2 ton status
Author
Joined
Jan 24, 2001
Posts
1,691
Reaction score
1
Location
--
It ended up in the return line...
 
Last edited:
A "dead-end" line won't give accurate measurements. You want it in the pan or where the fluid will flow past it. Most recommend in the return line from the cooler or in the pan. I have one on the send line and one in the pan. I just put it in to double as drain plug.
 
I put mine on the return line from the cooler. There are different schools of thought on this. I did it this way to see if my cooler could handle the job.
 
I put a sensor in both the return and output line coming out of the tranny. Then I had a switch in the cab that I could toggle back and forth to see the differance. It isnt necessary but I liked it. Just a thought
 
I had mentioned before using one of the pressure port fittings. No it won't be accurate as to what the in or out temperature is, but if idle (or normal) temp of the tranny is X degrees (regardless of where measured) then when you see it rise quickly, you know you have problems. It will measure cooling effectiveness IMO, but obviously won't give you in/out line temp.

If you ask me, since no one can give a straight, knowledgable answer on exactly what the trannies are SUPPOSED to run (I'd bet just over 195* or else it wouldn't be cooled in the radiator factory) temp wise, what it actually runs at is unimportant, as long as you KNOW when something is going wrong, or you need to give it a break, etc.

Putting the temp sensor in the pan is not really any better than the pressure fitting IMO, since the fluid is co-mingling at that point.

I don't like cutting tranny lines, that fluid is under a fair amount of pressure, and likes to leak.
 
Just out of curiosity are you seeing different temps between the two sensor locations? I mounted mine in the pan. My thought is I want to see the temp AFTER it has been through the workings of the tranny. I'm really curious to see if the temp reading in the outgoing cooler line reads close to the same. I wonder if going through the pump raises the temp.
I do dig the easy of draining. Why trannys don't get a drain plug is beyond me. WHAT a mess when you go to service the tranny.
 
The pan is always cooler than the transmission output line, which logically should be the case. I see up to 160 at the tranny output, but only about 120 in the pan /forums/images/icons/smile.gif . My lockup clutch went out before on my old 2000rpm stall torque converter and I saw it go over 210 if I would try to use 4th gear and then come to a stop /forums/images/icons/frown.gif (of course I only used up to 3rd gear until I got that fixed). The return line and the pan should be about the same. The fluid comes from the pan, goes through the filter, through the pump and into the workings of the tranny. Then the last stop is the torque converter (your greatest source of heat) and then through the output line to the radiator heat exchanger, on to your external cooler (because you should have one), then down the return line where it dumps back into the pan.
 

Latest Posts

Top Bottom