Transmission fluid

Discussion in 'Gen 2 Prius Technical Discussion' started by Benjamin13295, Jul 16, 2018.

  1. ChapmanF

    ChapmanF Senior Member

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    The best information I have is looking in the Gen 2 deep dive video, where you clearly see an oil drain passage from the MG2 stator area (29:09 in the video), and an oil catch structure (27:18 in the video) that matches the one shown in the later Gen 3 illustration where it is clearly described as cooling the stator.

    Without finding anything more definitive, then, it sure looks like not much changed from Gen 2 to 3 where we know the windings are cooled in oil. So if somebody wants to say that in Gen 2 they weren't, there would be a burden of proof involved.
     
  2. koco

    koco Member

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    Or a burden of proof to state that the windings are immersed. I have seen gen 2 transaxles at the junkyard taken apart and left abandoned on the ground that are dry of oil; this is circumstantial, but coupled with other information eluding to the fact that they are dry causes me to lean heavily to the dry side.

    I guess the Weber Univ. auto dept. has an email address for this inquiry.
     
  3. ChapmanF

    ChapmanF Senior Member

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    I've linked to what evidence I've found; if you've found "other information [alluding] to the fact that they are dry", the thread could benefit from linking that too.

    We probably should avoid getting hung up on the word 'immersed'; the oil only comes up to the level of the fill hole. The "conventional motor cooling structure" described in the Sano, Yashiro, et al. paper is describing oil that circulates onto the windings from above and returns to the sump from below.
     
  4. koco

    koco Member

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    I'm ok with the fact that 1st gen Prius has fluid for cooling the windings whether it is coolant or oil, I never debated that. I was discussing the 2nd gen only because there is a difference.
     
  5. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    So far as I know, no generation immerses the windings in ATF, but they all have some method of dribbling ATF on the windings to cool them.
     
  6. koco

    koco Member

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    If the ATF were dribbled onto the windings, it seems less risky from the standpoint of shorting something out.
     
  7. ChapmanF

    ChapmanF Senior Member

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    That seems to be the crux of a claim you've repeated a few times now. Of course there are differences Gen 1 to Gen 2, but you seem to be specifically claiming a difference in whether the oil gets on the windings. I'm not saying you haven't got support for that claim, but if you have, it would be a contribution to this thread for you to supply it.

    That's an interesting way of thinking about it. We know from the Gen 0 to Gen 1 paper that Toyota believed there was a good enough reason to revisit their resin formula if there could be oil getting on the windings, and it certainly wasn't "immersion" they were thinking of, because "immersion" has never been a thing in any generation of the tranny that they've built.
     
  8. koco

    koco Member

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    I suggest you write to Weber University's automotive dept. if you wish to continue your research efforts on this matter. Perhaps an opinion provided by someone there will have more weight to influence your decision as I will probably not be taking the time to look for source citations about this. Weber University looks to be a good resource for the academic resources you are seeking especially if you will not accept a discussion of opinions presented here, and ultimately they are not always facts...just opinions.

    At any rate, the proof is in the pudding, so bring on the pudding but don't use it in the transmission.

    On another note, I have seen some research findings involving Toyota WS fluid, and the results were not so great for that that product compared with lower cost synthetic fluids.

    On yet another note, Toyota introduced a no dipstick transmission with "lifetime fluid", but an owner would be foolish not to change the fluid. This move was done to circumvent a large environmental fee placed upon companies producing products that will introduce waste into the environment.

    These large corporations are clever, and will often not act in the best interests of their consumers.
     
  9. dolj

    dolj Senior Member

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    Actually, the proof of the pudding is in the eating.
    Now I just think you're just making stuff up based on personal bias.
     
  10. koco

    koco Member

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    It is ok for you to think that. Are you sure you're not gaslighting?
     
    #30 koco, Oct 21, 2021
    Last edited: Oct 22, 2021
  11. edthefox5

    edthefox5 Senior Member

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    G2 the windings are not exposed to fluid. G3 they are. Had this discussion with Prof Weber years ago.
     
  12. ChapmanF

    ChapmanF Senior Member

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    Ok, since koco has been content to 'mention' stuff and not provide any links, is it possible that you could help? Did your conversation with Prof. Kelly (I presume, at Weber State University) take place on a forum or comments page or any source that can be linked to and viewed? Was it an email conversation you might still have?

    I ask because we have documentation that Gen 0 was not exposed to fluid and they changed that for Gen 1, and we have documentation that the way the motors are exposed to fluid changed between Gen 3 and Gen 4 (that paper just said "the conventional motor cooling structure" for the way it worked in Gen 3).

    What we don't have yet, in any of these threads I've seen, is actual documentation that they made Gen 2 different from the gens before it and after it (but still cast the same oil channels into the case that you can see in Prof. Kelly's videos). If you have that, it would be a valuable addition to the thread.
     
  13. koco

    koco Member

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    What kind of a forum would this be if everyone was required to provide source citations for everything? It would be an academic forum.

    I can understand the need for source citations on an academic forum, but not here. If you want it so badly you should research it, create it and publish it, otherwise this will mostly be a discussion of our opinions and the reasoning behind them.

    In the weber university's gen 2 transmission video's section about "center case differences", you will see the parts of the inside that may or may not indicate oil or coolant flow within the case.
     
  14. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    It would be better and more useful. We get folks who spread falsehoods, and are persistent at spreading them. I try to document all I can and I still am in error occasionally. If you dislike the citations, just skip them. If you refuse to provide sources, expect to be ignored and lonely.
     
  15. koco

    koco Member

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    It is on your discretion and critical thinking skills, or lack thereof to distinguish between fact, opinion and BS in this type of forum. At any rate, I really don't see the frequent use of source citations from scholarly journals and peer-reviewed papers here. Websites, Wikipedia, magazine and newspaper articles do not qualify as credible sources in an academic setting anyway.

    The ones who desire further research are free to pursue it, but I am not willing to put in the time in an effort to placate a gaslight or someone with a different opinion.

    If someone is truly offended by those with differing opinions and lack of credible sources then they can choose to interact with those of the same opinions. A group of people always agreeing with each other would sure not make for stimulating discussion.
     
  16. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    Well, I have had enough of that.
     
  17. ChapmanF

    ChapmanF Senior Member

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    Opinions are splendid, but a great thing about this forum is how many of its threads (as forums go) eventually end up adding facts to our knowledge, and those threads are good ones.

    Lots of things are useful besides published articles. A link to an exchange with Prof. Kelly, say, is a perfectly reasonable thing to include, if that's something you're basing a position on. Lots of people here are familiar with his videos (the ones where you can see the oil channels in the case).
     
    #37 ChapmanF, Oct 26, 2021
    Last edited: Oct 26, 2021
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