Transmission oil change.

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Daniel Richard, Aug 29, 2019.

  1. Daniel Richard

    Daniel Richard New Member

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    2010 Prius
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    I bought a 2010 a couple months ago. A young girl owned it and I am slowly doing the maintenance she neglected. The car has 230000 miles on it. I assume it has never had the tranny oil changed. I know with a conventional transmission if you have never changed the oil at this mile mark, you shouldn’t.

    Is there any problem with changing the oil in a CVT transmission for the first time with such high mileage?
     
  2. Peter123

    Peter123 Junior Member

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    2011 Prius
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    Two
    It shouldn't be a problem. The transmission fluid in a CVT is for lubrication only. There is no hydraulic pump, no torque converter, and there are no solenoid controlled gears to shift. I would however check that the fill plug (the upper one) isn't frozen on before taking out the drain plug. Use the Toyota brand transmission fluid.
     
  3. Mendel Leisk

    Mendel Leisk Obtuse Angler

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    Location:
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    Vehicle:
    2010 Prius
    Model:
    Touring
    Yeah Owner's Manual strongly recommends Toyota ATF WS fluid, and cautions that using any alternate may cause damage. That's regularly debated here, but I wouldn't gamble.

    You will need 4 quarts (or liters), and will probable use about 3.5. Also good to replace the drain and fill bolt washers. The dealership parts departments should have both items. Up here the fluid is just over $9 (CDN) per liter, and the washers were around $3.80 apiece (exhorbitant):

    1. Raise and level the car. (Level car is mandatory to get the fill level right.)
    2.. Remove fill bolt (Just as a precaution, you don't want to drain the fluid, then find the fill bolt stuck).
    3.. Remove drain bolt, with a catch pan of some sort under.
    4. Reinstall drain bolt with a replacement washer, torque to 29 ft/lb.
    5. Add new fluid through the fill hole, till it starts coming back out. (I found a funnel with hose extension from above very simple (keep hose OD 5/8" or less, to fit fill hole with a little spare). Good to have an assistant pouring. Go slow after 3 quarts.)
    5. Install fill bolt with replacement washer, same torque.

    Notes:

    a) Both drain and fill bolts are socket-head-cap-screw type, with a 10mm hex recess. You need a 10mm Allen Key style socket. Stanley for one makes a set.
    b) Recycle any left-over fluid. Toyota recommends to only use fluid from freshly opened bottles.
     
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