Transmission don't shift after head gasket change

Discussion in 'Transmissions' started by Burros90, Mar 20, 2019.

  1. Burros90

    Burros90 Member

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    Hello Maverick/Comet team,
    I have recently changed the head gasket of my 74 Maverick is a 6 in line 250 engine. After all got installed back, the transmission was having problems shifting gears, I've been told the link from the carburetor has to get adjusted in order properly work, however I did not mess with that link, other than remove it before to take off the carburetor. Would you guys mind to shed some light here, I'm really anxious to take my car for a spin, but before of anything I want to make sure I won't mess the transmission. Any help is greatly appreciated.
     
  2. RMiller

    RMiller My name is Rick

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    Check the vacuum modulator line. It needs to be connected to manifold vacuum to work properly. If it's hooked to ported vacuum or not connected the trans does goofy things.
     
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  3. Krazy Comet

    Krazy Comet Tom

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    Agreed, vac line to modulator is disconnected.

    Should be a simple fix.
     
  4. Burros90

    Burros90 Member

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    Hi there! thanks to both of you for your responses. I did not hooked couple of lines were coming from the manifold to the carburetor, one about 1/2" tubing and other 1/4" tubing, both were pretty rusty and broke when I disconnected them. My biggest issue is that I can't find the fitting any more any where, everyone tells me those fittings are very special automotive fittings. I'm attaching couple of pics of the two ports where the 1/2 tubing was connected at the manifold and ant the carburetor, would you be so kind to let me know if that is what are you guys referring to?
     
  5. RMiller

    RMiller My name is Rick

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    Total stab in the dark without the images but it sounds like you found the problem. The larger port is probably PCV and the smaller the transmission modulator.
     
  6. Krazy Comet

    Krazy Comet Tom

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    The transmission modulator should be connected with nothing more than a piece of rubber hose connected to ¼ tubing. The larger tube is for either power brakes(also connects with rubber hose) or EGR. Because of heat EGR must be seel tubing. I'd block it off and forget it was ever there.
     
  7. Burros90

    Burros90 Member

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    Hi guys, thanks for the great & quick interaction. I’m having hard time loading pics. I’ve contacted the admin to see if he could help me with that.
    I do remember that little rectangle piece screwed to the manifold, with several different ports, I’ll make sure it gets connected to the rubber then to the back of the car with a tubing piece. I’ll try to load pics soon. Thanks.
     
  8. RMiller

    RMiller My name is Rick

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    Follow the hoses that were attached to that block and see where they go, that will tell us a lot.
     
  9. Burros90

    Burros90 Member

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    RMiller / Crazy Comet,
    After few weeks of traveling, finally this past weekend got back home, & after a moderated list of honey do's for Saturday. Sunday afternoon, got under my car, followed the tubing lines and guess what? both of them were off the port at the transmission... I tip my hat to you gentlemen! you really are great people, vast knowledge!! but more important that you're willing to share it with rookies like me. thank you so very much!
    If you ever come down to the Houston, TX area, please shoot me an e-mail: burros90@hotmail.com. I'll be extremely happy to take you guys to a great BBQ or authentic Mexican cuisine.
    God bless!!
     
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  10. RMiller

    RMiller My name is Rick

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    I can't speak for Crazy Comet but I learned this one the hard way when I was 16. I had a 66 Malibu that was scabbed together and that stupid line kept falling off due to an oil soaked hose. Drove it for a week with a transmission that was acting like it was dying. Told my grandpa about it and he showed me the problem and how to fix it. Glad you got it figured out!
     
  11. MCCI

    MCCI Official Voice of MCCI

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    It's funny, we just had a Maverick/Comet mini-meet and get-together in Houston this past Saturday at Hubcap Grill.
     
  12. Krazy Comet

    Krazy Comet Tom

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    Not sure when I learned about the modulator vac line(s), probably on a '67 Falcon 289/C4 that was slipping on 1-2 shift. Intermediate clutches were toast, common issue with the '60s C4. After I replaced trans with a used and that one failed a year later, I swapped the 289/C4 for a 351/FMX combo from a '69 Torino GT.

    My first car was a '57 Ford that used a throttle controlled rod, similar setup to early AOD.
     
  13. Burros90

    Burros90 Member

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    All,
    Thanks a lot for all your responses, now my car is running really smooth... most important learned about vacuum lines importance.
    Loaded few pics from under the hood of the car. once again thanks a lot.
     

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  14. RMiller

    RMiller My name is Rick

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    This is the one thing people never forget once they have it happen to their car. Next time someone has this issue you get to be the hero! Glad it's going again, enjoy!
     

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