Tracking-Down a Vibration

Transmissions and Rear Ends

  1. Jonnyuma

    Jonnyuma Well-Known Member

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    I just noticed this yesterday... as soon as the trans shifts into 3rd, there it is.
    Let off the gas... gone
    Back on it... dang.
    It's extremely subtle. So subtle that I had to convince myself that it was real and not just exhaust rumblies. In fact, if the other two gears weren't so smooth, I'd probably never even notice it.
    This is the 904 in my 79 Lebaron. The fact that it comes on right at the upshift makes me think (fear) it's internal vs U-joints or a bad biscut, but I'll be looking at those too.
    Whaddaya think?
     
  2. jasperjacko

    jasperjacko Well-Known Member

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    do you have a lockup converter?
     
  3. Jonnyuma

    Jonnyuma Well-Known Member

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    I think yes. I'm pretty sure it's the factory unit so if that's what Ma was using then that's what I've got. I seem to remember reading somewhere that they went to a lockup tc in 78 or 79.
     
  4. Jonnyuma

    Jonnyuma Well-Known Member

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    I think yes. I'm pretty sure it's the factory unit so if that's what Ma was using then that's what I've got. I seem to remember reading somewhere that they went to a lockup tc in 78 or 79.
     
  5. volare 77

    volare 77 Well-Known Member

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    I had a vibration that drove me crazy. Replaced driveshaft and checked about everything. Found out it was a cracked flex plate.