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Shorted MG? Codes pulled. May need transaxle.

Discussion in 'Gen 2 Prius Technical Discussion' started by Lam, Apr 1, 2013.

  1. Lam

    Lam Member

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    Also, I finally got some time to upload the rest of the pictures.
     
  2. Lam

    Lam Member

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    I'll dump the tranny fluid this morning. If it is a bearing failure, maybe I can just take the MG2 out of the transmission and put it into my old one? So between the two I have one good transmission, hopefully the bone yard will warranty the thing and not ask for it back.
     
  3. edthefox5

    edthefox5 Senior Member

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    Carolyn discusses doing just that on the car while the trans is still installed.
     
  4. Lam

    Lam Member

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    So I decided to lift the car onto jackstands, turn off the traction control and inspect the sound.

    It is coming from the passenger side wheel. Below is a video of the sound. I crawled underneath and took a stethoscope to the transmission and it sounds like it is definetely coming from the wheel/hub assy. No indication of sound from the transmission itself.

    Any ideas? Video below

     
  5. bedrock8x

    bedrock8x Senior Member

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    Disconnect the half shaft to the wheel and run the car again, if it is the wheel bearing, the noise should disappear.

     
  6. Lam

    Lam Member

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    I thought about doing that, but if i pull the halfshaft, won't fluid start coming out en masse? also, not sure how i could do it safely.
     
  7. bedrock8x

    bedrock8x Senior Member

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    You may loose some fluid but not en masse. Didn't you have to pull the half shafts when you replace the CVT?

     
  8. Lam

    Lam Member

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    Yes, to clarify... the sound is only audible around 70 mph. Not sure I want to spin a loose halfshaft at 70 mph, even with the axle out of the trans completely.
     
  9. Lam

    Lam Member

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    Also, the sound is entirely speed dependent
     
  10. bedrock8x

    bedrock8x Senior Member

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    Pull the half shaft from the transmission, you are not spinning the wheel and the half shaft.
     
  11. edthefox5

    edthefox5 Senior Member

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    Sounds bad. Very loud. I think I understand about the half shaft. If the inner is removed there's just a hole there in the side of the trans at that point if I am understanding. Can't run the car like that.

    Doesn't sound like wheel bearing. And the sound was not there before cvt swap?

    I have complete confidence that a dude that can do what you did in your garage can easily find this issue. You have skills my man.

    Take a deep breath and 2 beers and just sit and stare at it and ponder...lol...that's what I do. And I usually figure it out and you will too.

    God luck to you!!
     
  12. Lam

    Lam Member

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    I hate shotgunning parts, but i'm just going to buy a hub assembly tomorrow and put it on to see if it is the problem. If not, well. I better look into the warranty on the transmission. Does this sound, sound like the problem you indicated about the winding problem that causes sound in the pass wheel side?
     
  13. edthefox5

    edthefox5 Senior Member

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    No...its more of an ominous hum/rumble because in that scenario you have high voltage leaking in the trans from a damaged motor winding and the phase that winding is supporting is not working so the mg is really out of phase and very unhappy and unbalanced. Ever hear a big 3 phase motor that's lost a phase? But it will quickly throw a ground fault nag too that your not seeing. So...interesting...don't think you have a bad winding...sounds very mechanical and LOUD!

    But you know now that I thought about it taking the inner half shaft out of the trans may not be a bad idea. Somehow with tape maybe (very temporary) cover the axle hole so the fluid does not make a mess and run it up real quick and see if it's making that god awful racket. It sounds really bad on your post or is that just the ICE/trans making all that racket?
    Be aware though with all running gear/load removed on that axle side it may not make the noise as loud as before. .

    Anyway run it up real quick in inspection mode and see if it's making that sound your hearing with that HS out. If so oh well we know its the trans then as all running gear is eliminated. Kabeesh?
     
  14. Lam

    Lam Member

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    Ed, again thanks for the input.

    I shotgunned a wheel bearing though and that was it. Oddly though, it only started making noise when the bearing heated up... around 72 mph to be exact. My guess what happened is when I used PB blaster on the axle nut from when I pulled the transmission (it was *VERY* stubborn and was crossthreaded) it carried all the crap from inside the wheel into the bearing and killed it.

    So learn from my mistake, use PB blaster with caution here and clean out as much of the garbage as you can before you hose it down.
     
    nh7o likes this.
  15. edthefox5

    edthefox5 Senior Member

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    Ahhh....pb blaster contamination. Couldn't figure out how your trans swap blew up a wheel bearing. Man it was loud!!! Very cool. I hate PB blaster it stinks so bad. But PB does make the best spray grease its called CSP Spray.
    Corrosion Stop Protectant.

    Its a thick spray grease that stays where you spray it and does not smell at all. I have sprayed the undercarriage and all running gear on all my cars for years with that stuff and no squeeks, rattles,clunks and best of all I have no rust on anything under the car. Works really good.

    This stuff found at Home Depot only:

    Blaster 11 oz. Corrosion Stop Grease-16-CSP at The Home Depot

    Btw, best way to get a nut off that's stuck is to freeze the bolt or in your case the axle hub. Buy a can of Freeze spray it really works good. Roll up a piece of paper to concentrate the area and freeze it. The metal will shrink away enough from the bolt to allow you to break it free. Also I use a 6 foot long piece of emt pipe from Home Depot that slips over the breaker bar. I have like 4 different lengths of 1"' EMT cut for various spaces. Just wear safety glasses and don't use cheap sockets.

    Freeze spray:

    MCM Electronics - Search Results for freeze spray
     
  16. Lam

    Lam Member

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    Never heard of that stuff, I got to give it a try. I used a similar technique with canned air to get the wheel bearing out of the hub. Used it to freeze the inner bearing, then used a big hammer to extract it. Did it without a press.
     
  17. edthefox5

    edthefox5 Senior Member

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    Yup works perfect for that too...
     
  18. mgb922

    mgb922 Junior Member

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    Yes change the oil. I think the book says at 110k or serious damage can occur. Although the oil is synthetic is has to be able to deal with electronics and after a while can't. Amazon.com 4 qts about $50 AFT WTS. Just did mine you'll need a funnel with a piece of surgical house attached, a pan, can't remember the size of the top plug but it'll take a socket. The drain plug is a hex drive again not sure of the size. I used a 3/8" hex stock but it was lose. I filled it to over flowing and let it drain. Then to get the proper amount used and manual brake bleeder vacuum pump to bring it down to I think .2 below the fill plug, check the book. DO NOT OVER FILL is the warning in my book. If I bought a high mileage prius I would have immediately changed the engine and convergent coolant, transaxle oil, brake fluid, plugs, check or change the PCV. Whether it needed it or not. Priuses don't need much maintenance and ordinary folks seem to think it'll just run forever.

    One more thing. Jack the car LEVEL!!!
     
  19. edthefox5

    edthefox5 Senior Member

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    Lol...

    He's already changed out the cvt. Was chasing a sound and found it was the wheel bearing.

    "has to able to deal with electronics and after a while can't"