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Transmission fill plug behind driver's side wheel?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Chris Perry, Jul 4, 2024 at 11:36 AM.

  1. Chris Perry

    Chris Perry New Member

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    I just changed my tranny fluid and when I refilled it I used a fill plug on the upper driver's side of the transmission (behind the tire) to put my 4 qts in. It was a 10mm hex bolt, just like the drain plug. It did not have a crush washer on it.

    Then I was re-reading the directions and everyone says to fill the transmission from the 24mm plug that is in the center of the transmission. I guess I should have re-read the directions before I did it.

    Anyway, all the fluid seems to have gone in. I drove it around and it seemed alright. What do you think? Is it okay, or did I mess it up?
     
  2. Tombukt2

    Tombukt2 Senior Member

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    The only thing that's important here is that you get the right amount of fluid in the transmission and it doesn't come back out onto the ground so mission accomplished and that's that I would imagine no matter how you got it in there it's in there.
     
  3. dolj

    dolj Senior Member

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    In this case, "everyone" is correct. The fill plug is in the same vertical line as the drain plug only higher up on the front-side of the transmission housing.
    No, you messed up. Let's hope you haven't done any damage to the transmission driving the car without transmission fluid.
     
  4. Tombukt2

    Tombukt2 Senior Member

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    I thought he added fluid where did it go straight on the ground so he's laying in it?
     
  5. Mendel Leisk

    Mendel Leisk Senior Member

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    If you add the spec'd quantity through a top hole, I "think" you're ok. The advantage of filling through the usual fill hole (assuming car is level): it's self-levelling. You pour till it starts coming back out; that's the correct level. Pouring through the top hole, you don't really know how much residual fluid was in there.

    In your shoes, I'd raise-and-level the car, take out the usual fill bolt. If a little comes out, let it happen, and your good. If nothing comes out feel with a pinky: if it's close you're ok. If you can't feel anything then top it up, till it overflows, and your done.
     

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  6. Tombukt2

    Tombukt2 Senior Member

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    Yep like feeling an old differential the one in the back that drove the rear wheels You filled it till it was level with the hole stuck your finger in and the tip got wet put the cat back on same with the Prius It's just hard having it level and accessing that plug without a rigged up dispenser which is easy to make
     
  7. Georgina Rudkus

    Georgina Rudkus Senior Member

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    All these steel plugs were designed when transmission pans were steel or differential cases were cast iron.

    Toyota and most other manufacturers wanting to reduce parts inventories kept the steel plugs even when cases were switched to cast aluminum.

    Now, I use M18x1.5 aluminum magnetic drain plugs widely available from aftermarket vendors.

    The 19mm hex and the compatible metals minimize galvanic corrosion. The assembly is also compatible with the aluminum crush washers.

    The magnets pick up worn steel particles from the gears. The 19mm hex means no stripped out hex sockets.

    And, no large 24mm wrench which most individuals not usually already own need not be purchased.