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Transaxle hum but no warning lights.....help???

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by sfv41901, Feb 23, 2012.

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  1. edthefox5

    edthefox5 Senior Member

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    Yikes..Yes I thought so too...especially with the wife at the helm!!:p

    But the cool thing is if she can go into EV and quiet it down there while he's under there he should be able to hear it and pin point it. But I still bet its pretty loud mechanically under there.
    Its got to be a bearing in the chain area as posted or something in the planetary or maybe in the diff. Since its so close to the inner cv joint I think its something bad in the differential. Which is a mechanical noise but no electronic issue hence no code.

    Would drive me bonkers.
     
    #21 edthefox5, Feb 25, 2012
  2. edthefox5

    edthefox5 Senior Member

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    Hey did you see the video post in Prius Chat Technical Discussions titled " Hybrid Synergy Teardown" where the tech plainly says they had a shorted winding mg that did not throw any cel's. Check it out.

    The video is off You Tube.
     
    #22 edthefox5, Feb 29, 2012
  3. sfv41901

    sfv41901 Masta S

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    So I wonder if its a bearing inside thats making the noise........might this be why I'm not seeing any warning lights?
     
    #23 sfv41901, Mar 1, 2012
  4. edthefox5

    edthefox5 Senior Member

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    No the tech is saying he has seen a shorted winding mg with no
    cel's.
    But not having heard the hum I can't say if its a bearing or a winding hum.
    People post about a hum its been the transaxle. Wheel bearing has been a wup wup for instance.

    If a mg is shorted its pretty obvious. Really poor mileage and excessive temp in one MG. You have a Scan Gauge now whats the mg temp?
     
    #24 edthefox5, Mar 1, 2012
  5. sfv41901

    sfv41901 Masta S

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    I just got the kiwi yesterday. I have everything set up.

    I will get a screen shot on my way to pic up my daughter.


    I did notice that my mpg has dropped. I use to get 50mpg on my commute. Now I'm getting about 38-40mpg.
     
    #25 sfv41901, Mar 1, 2012
  6. tedjohnson

    tedjohnson Member

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    That video clearly shows a bad internal transaxle bearing as well
     
    #26 tedjohnson, Mar 1, 2012
  7. sfv41901

    sfv41901 Masta S

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    So far these have been no fault codes stored by the ECM.

    When the Prius went into ready, this is what the temps were.

    Prius was in the garage & ambient temp was 61deg F.


    [​IMG]

    This next img is after driving for 20mins. Ambient temp was 52deg F.

    [​IMG]
     
    #27 sfv41901, Mar 1, 2012
  8. edthefox5

    edthefox5 Senior Member

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    yes but transaxle coming out either way so moot point.
     
    #28 edthefox5, Mar 1, 2012
  9. edthefox5

    edthefox5 Senior Member

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    I see the temp meters and they look ok but you have to drive it good for about 20 mins and watch for quick spike.

    BTW, how does it drive? Is it very low powered? If the power is ok
    and no cel's it must be mechanical. Just may be a bad bearing or chain.
     
    #29 edthefox5, Mar 1, 2012
  10. sfv41901

    sfv41901 Masta S

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    This was on the way home. Ambient temp was 54deg F:

    [​IMG]

    Power is there. Doesn't feel like its any slower

    I guess I will drain the tranny to see if there are any metal shavings on it.
     
    #30 sfv41901, Mar 1, 2012
  11. sfv41901

    sfv41901 Masta S

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    This was on the way home. Ambient temp was 54deg F:

    [​IMG]

    Power is there. Doesn't feel like its any slower

    I guess I will drain the tranny to see if there are any metal shavings on it.
     
    #31 sfv41901, Mar 1, 2012
  12. shaneb

    shaneb New Member

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    I have rebuilt several transaxles for the taxis. If the noise is reported early enough i can put a set of bearings thru it. If its not reported and i dont see the car for 3 weeks the cab has usually clocked up 10,000km by then and the bearing has ground itself into the transaxle case.
    The oil usually gives it away. If the alloy case has ground down the oil is black and i replace the unit with either a new one or a second hand one depending on the life of the car.
     
    #32 shaneb, Mar 2, 2012
  13. sfv41901

    sfv41901 Masta S

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    How hard would this be for the DIYer? Any secrets u can share? Where can 1 get these bearings? I really want to avoid having to replace the entire tranny if I can.
     
    #33 sfv41901, Mar 2, 2012
  14. sfv41901

    sfv41901 Masta S

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    So I thought I would share an update.

    I've replaced the old tires with new 1's......noise still there.

    Decided I would replace the axles.......Woohoo.......noise gone. Both axles looked good but I guess there was something starting to fail inside. Either way, problem solved. Thx to those who gave input.
     
    #34 sfv41901, Mar 23, 2012
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