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350 Lockup Transmission

Discussion in 'Chevy Trucks' started by mpastor, Apr 6, 2000.

  1. mpastor

    mpastor Junior Member
    Messages: 3

    Has anybody had any problems with getting a signal to the lockup solenoid on a 1981 350 lockup transmission? <br>Mine is in a 1981 2WD Blazer and the lockup works on the Tranny if a signal is sent from an external source but I don't know where to check to see why the original sending source isn't sending a signal.
     
  2. yortengel

    yortengel Senior Member
    Messages: 123

    Better go and check out a service manual at the library. I know that TCC lock up usauly has a vacuum solenoid and a cut out switch on the brake pedal. Checking the book should show you wath you have.<br>Good Luck
     
  3. mpastor

    mpastor Junior Member
    Messages: 3

    It's actually an Electronic solenoid not vacuum...thanks for the Library advise
     
  4. yortengel

    yortengel Senior Member
    Messages: 123

    The solenoid is electric, but there should be a vacuum switch under the hood, on the left side of the firewall, with one vacuum line and two wires. Atleast my truck has one there. I have a little different system. but I remember seeing them there. If I remember right they would inhibit lockup untill the engine warmed up. there was a TVS in the intake that controlled it. It was supposed to improve cold drivability. I have mine bypassed. I have never had a problem with the way my truck shifts. but that is what it is for.