Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

tranny temp sensor placement?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by jms, Jun 17, 2002.

  1. jms

    jms 1/2 ton status Author

    Joined:
    Jan 24, 2001
    Posts:
    1,683
    Likes Received:
    0
    Location:
    --
    It ended up in the return line...
     
    Last edited: Jul 27, 2008
  2. Blue85

    Blue85 Troll Premium Member

    Joined:
    Jul 26, 2000
    Posts:
    9,075
    Likes Received:
    486
    Location:
    Grand Rapids area
    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.
     
  3. Sandman

    Sandman 3/4 ton status Author

    Joined:
    Apr 15, 2002
    Posts:
    5,653
    Likes Received:
    0
    Location:
    Pocatello, ID
    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.
     
  4. Alex

    Alex Registered Member

    Joined:
    Jun 19, 2001
    Posts:
    78
    Likes Received:
    0
    Location:
    Northern California
    jms, sorry to change the subject matter, but where did you get the rack for your rig?
    Alex
     
  5. BlazerBoy

    BlazerBoy 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    639
    Likes Received:
    0
    Location:
    Chicago IL.
    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
     
  6. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,979
    Likes Received:
    189
    Location:
    Roy WA
    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.
     
  7. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    7,385
    Likes Received:
    0
    Location:
    Atlanta
    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.
     
  8. Blue85

    Blue85 Troll Premium Member

    Joined:
    Jul 26, 2000
    Posts:
    9,075
    Likes Received:
    486
    Location:
    Grand Rapids area
    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.
     

Share This Page