727 High pitched whine in D

Discussion in 'General IH Tech' started by scorp1us, Oct 16, 2014.


  1. scorp1us

    scorp1us High Wheeler

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  2. jdassler

    jdassler Farmall Cub

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    Does it change pitch with an increase in RPMs? Sounds more fluid than mechanical from the Youtube video.
     
  3. Oakland_Jack

    Oakland_Jack Binder Driver

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    It is hard to hear, but might be the teeth of the transfer case making slight contact on the front axle coupling. While in D, try slight manipulation of the transfer case shifter and see if there is an effect. If that's not it, turn up the radio louder and enjoy a refreshing PBR.

    -j
     
  4. FishWagon

    FishWagon Farmall Cub

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    Sounds like a fluid issue to me.....

    Check your level with engine running and the tranny in neutral (pump does not run while in park so it's important to be in neutral)

    When was last time filter was changed?
     
  5. JWMorrisey

    JWMorrisey Farmall Cub

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    As an old Chrysler tech, we ran into this issue back when these trans were new. The first one encountered, I actually thought it was a vacuum leak.

    The issue back then was that a poor weld job inside the torque converter would allow a few of the vanes to vibrate like a tuning fork in the fluid flow, causing this sound.

    Secure the vehicle properly and get underneath with a mechanic's stethoscope. From what I can see in the video, the truck isn't moving so that eliminates from the planetary gearsets on back. I'm betting the sound is coming from the torque converter or the bushings up in the front of the trans.

    FishWagon is partly correct in checking the trans fluid level in Neutral. The pump is working in neutral but pressure isn't regulated and the torque converter isn't filled in PARK. The fluid level could appear to be 2-3qts overfilled if it's checked on Park.

    SIDEBAR When the outside temps are 0 degrees or colder and the truck has set out overnight, start in Neutral to reduce the risk of blowing out the trans front seal.
     

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