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Change transmission oil on my '02?

Discussion in 'Generation 1 Prius Discussion' started by Trombone, Mar 24, 2024.

  1. Tideland Prius

    Tideland Prius Moderator of the North
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    For your information, your replies and coming in as Russian rather than English. If you are using an app like Tapatalk, it’s not transcribing into English for the rest of us.
     
  2. dolj

    dolj Senior Member

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    Interesting.

    I'm not sure putting engine oil in the transaxle is a good idea. What is the rational?
     
  3. nolik

    nolik New Member

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    if nothing happens in the box and the oil just splashes, then what is the problem, what prevents you from doing this?
     
  4. dolj

    dolj Senior Member

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    For me personally, nothing prevents me from doing this, it is just Toyota specified a very specific transmission fluid and as that is readily available I just use that. It never crossed my mind to use engine oil.

    I'm more interested in why you're taking the approach you're taking.
     
  5. ChapmanF

    ChapmanF Senior Member

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    For one thing, it splashes on the insulated electrical windings of high-voltage electric motors, and one goal of the prescribed oil is that it should not chemically degrade the insulation.

    Even more generally, oils have always been chosen for very specific conditions of viscosity, lubricity, and so on, and I can't recall any instance where the oil for a car gearbox was specified to be the same oil used in the engine; I would be unlikely to assume either one would be suitable for the other use.
     
  6. Trombone

    Trombone Member

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    Don't feed the trolls. Russian clearly isn't talking about our cars anyway. Ignorance in action.
     
  7. nolik

    nolik New Member

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    you're funny, I laughed. How is my Prius different from yours?
     
  8. mroberds

    mroberds Member

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    This is correct. You can't see the magnet unless you take the whole pan off of the transmission. At least for me, the magnet normally has a little bit of "fuzz" on it, as stated.

    For OP, or anyone else contemplating a transmission fluid change, you can get 6-packs of Toyota T-IV ATF on Amazon for roughly $50, delivered, in the US. At least for me, this is a lot better than I can do at the local dealer.

    I also recently discovered that the Dorman 095-149 aluminum crush washer is pretty much an exact replacement for the Toyota 90430-A0003 washer, used on the transmission drain and fill plugs. A bit over $2 and on the shelf at an O'Reilly near you.

    I very vaguely recall that some 70s Japanese cars (Datsun?) took engine oil - like, 10W40 - in their manual gearbox, but I don't know if 1) that's true or 2) it was a factory spec, or some kind of hot-rodder/enthusiast/lore thing. In that era I would have expected something more like 80 or 90 weight gear oil.
     
  9. Mendel Leisk

    Mendel Leisk Luddite

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    From 1990 Honda Accord Shop Manual:

    engine oil: 10W30 or 5W30
    manual transmission: 10W30 or 10W40

    80~90 weight gear oil was specd for something on our daughters previous 4WD Honda Pilot. Not the rear differential (which took a proprietary Honda fluid); it was another 4WD related component in the engine bay, transfer case or similar?
     

    Attached Files:

    #29 Mendel Leisk, Apr 13, 2024
    Last edited: Apr 13, 2024
  10. Trombone

    Trombone Member

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    Mission accomplished! Transmission oil drained, pan removed and cleaned, reinstalled with new gasket, refilled with Toyota T-IV. The pan was surprisingly clean, just the expected sludge around the magnet, but no big pieces, filings, shavings, etc. I didn't really expect any. The old gasket looked like it could be reused, but I provided a new one and they used it. Car has 162,626 miles on it. There had been a previous fluid change at around 90,000, but the pan was not dropped at that time, so today was the first time that pan has seen daylight since it left Japan. Currently getting 47.8 mpg. Going out for a ride now to enjoy the refreshed vehicle.

    BTW, I had this serviced at the dealer. The charge was $272 and change; most of that was labor. They didn't gouge me on the T-IV, $43 for the 4.5 quarts. I'm not complaining. At an earlier time I might have tackled this job myself, but I'm past wanting (or being able!) to get under the car and make a mess; I can do engine oil changes, but that's about it. The car should be good for another 100K miles.
     
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