Transmission fluid coming out of dipstick

Discussion in 'Transmission & Driveline Topics' started by cubfan226, May 1, 2006.

  1. cubfan226

    cubfan226 Veteran Member

    627
    0
    Feb 7, 2006
    Arlington, TX
    A week ago I took my finally-running '70 for a short drive. First to the gas station (~2 miles), then got on the highway, and exited at the first exit (~1.5 miles). I stopped at the light and when I turned, this huge cloud of smoke enveloped the car behind me. It was bad. There was also smoke coming from the edges of the hood. I pulled over and noticed a few drops of coolant coming out the overflow. Thinking I had overheated, I waited 30 minutes and drove slowly home (2-3 miles). The next day I noticed fluid under the car that was light red. Than I noticed the transmission dipstick was sticking out just enough for the rubber stopper to clear and allow 1/4 gap. Right in that area, everything had been sprayed with trans fluid.

    I was thinking I had left the dipstick undone and that the fluid spurted out (like the oil would), but now I understand it shouldn't spurt out even if the dipstick is ajar.

    So, I read some posts here and learned I may have (1) a clogged vent on top of the tranny case, (2) constricted/clogged cooling lines, or (3) some other problem.

    I've never worked on a transmission. Where is the vent and how do I clean it? Is there a good way to check/clear the cooling lines? What about the radiator portion of the cooling lines? Do I take off the lines and blow thru them all? Any other ideas on what could cause this? Thanks for any help/suggestions!
     
  2. 10secZ28

    10secZ28 Member

    57
    0
    Mar 26, 2006
    Kingsville,Ontario,Canada
    A Buddy of mine had the same prob,his came out a few "" and shot fluid all over when he let off the throttle at the end of the track.It ended up being the vent up top was clogged with dirt,we cleaned it out and it was all good.Just take a peice of mig wire or something and run it through,if it is clogged,it builds up pressure,and finds the easiest way to release itself,thus blowing out the dipstick tube cause there isin't much pressure holding it in.Steve..
     
  3. cubfan226

    cubfan226 Veteran Member

    627
    0
    Feb 7, 2006
    Arlington, TX
    In the picture below, is the vent tube what I've circled in red? Does it pull out? I pulled on it, but it wouldn't do anything. It seems to have a black plastic cap on it. Am I not pulling hard enough? Does twist off? :confused:

    [​IMG]

    Thanks
     
  4. 10secZ28

    10secZ28 Member

    57
    0
    Mar 26, 2006
    Kingsville,Ontario,Canada
    I am not 100%here but does it thread out??,I know on my th-350,the cap pop
    on & off,??.Steve..
     
  5. 79silverz28

    79silverz28 Veteran Member

    726
    0
    Jan 6, 2006
    Texas
    Hmm....

    That does look like the problem. On almost every tranny I've seen, there is a little tube that comes out of that hole, not a plug.

    Here's a link to a pic that might help :

    http://cgi.ebay.com/ebaymotors/REBU...059871206QQcategoryZ33727QQrdZ1QQcmdZViewItem

    Go to the bottom and look at the picture, you'll see the little tube. If you don't have a vent, then that's exactly what will happen, fluid coming up through the dipstick, since it's the easiest thing to give under the pressure.
     
  6. cubfan226

    cubfan226 Veteran Member

    627
    0
    Feb 7, 2006
    Arlington, TX
    I went to a recommended transmission shop. They told me the black cap is normal - half the cars have the tube, half have the cap (actually they said many have the cap removed and no tube). Apparently, the black cap is just to keep dirt out.

    They said to check the top vent first by blowing air down the dipstick tube with a compressor. I did this and I could feel air coming out from around the black cap, which is a loose cap that turns.

    The next thing they suggested was to see if the cooling lines were restricted. I haven't done this yet, because I could have cleared the vent obstruction when we sent the air down the dipstick. Plus, unattaching the cooling lines from the tranny looks like I'm going to have to take stuff off to get to them, e.g. starter and possibly pass headers.

    I won't know for sure until I get it back on the highway. After reading about cars catching fire when the transmission fluid hits the exhaust manifold, I'll be taking a fire extinghuisher with me this next time.
     
  7. cubfan226

    cubfan226 Veteran Member

    627
    0
    Feb 7, 2006
    Arlington, TX
    Just to follow up......our problem was a bad torque converter. We were ALSO having to rev it up pretty good from a stand still to get it moving. The new torque converter fixed the slow start up and the tranny fluid spray.
     

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