Transmission shifting weird

Transmissions and Rear Ends

  1. MoparDan

    MoparDan Well-Known Member

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    The transmission seems to be shifting strange so I drove a few different ways: normal driving: I felt it shift three times: at about 20 mph, then about 30 mph, then about 50 mph, i thought this was a three speed transmission so why would it shift three times? Next I hit the gas pedal harder the usual: shifted twice first at about 35 mph then at about 55 mph. Next I got on the highway a just floored it to about 80 mph, and there was only one shift at about 50 mph and it was a pretty rough shift. I know almost nothing about transmissions but this doesn't seem right at all
     
  2. Aspen500

    Aspen500 Well-Known Member

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    I think the extra "shift" you're feeling is the torque converter clutch engaging. It will cause an rpm drop and can feel like a gear shift to some extent. Usually 200-300 rpm roughly. That's my guess anyways, going by the description you gave.
     
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  3. MoparDan

    MoparDan Well-Known Member

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    I should add car is a totally stock '85 Gran Fury with transmission code DGA, and yes I did check the fluid level and its fine, I did have the fluid and filter changed but that was a few years ago, it should also be noted that this was in a flood during the last hurricane and both the engine and differential had filled with water and had to be drained, the garage said the transmission fluid looked fine
     
  4. MoparDan

    MoparDan Well-Known Member

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    That makes sense, it felt like three shifts so maybe one time its was the torque converter. I never really paid attention to when it was shifting until yesterday, I really know nothing about transmissions except how to check the fluid level
     
  5. BudW

    BudW Moderator Staff Member

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    It is the TCC (Torque Converter Clutch) engagement you are feeling - so it is normal.
    Sometimes you can feel it shift four times if driving up a small grade at low throttle position (2nd, 2nd w/TCC, 3rd and 3rd w/TCC).

    Note: you are getting about 10% better fuel mileage anytime the TCC is engaged – because there is normally 10-15% slippage inside of a torque converter when cruising.
    The TCC turns off when power is applied, so it can use the torque multiplication the converter provides. When load is removed, the TCC re-applies


    Right now, I’m not far from building either an A727 or A518 for my Fifth Ave. If I was going to race it full time, a non-lockup might be the way to go (fewer things to break). Sense my car will be 95% (or more) street driven, I want a lockup clutch for it, for the increased fuel mileage.

    My ’77 wagon does not have lockup – and I miss it.
    Chrysler came out with it mid-year ’78 – so a few big blocks came with lockup.
    BudW