Transmission fluid change at 150k miles?

not that i recall. but there probably isn't any hard data on whether it's good or bad at this point. i would probably do it.

 

I would do it. It's an easy DIY, and dealerships are getting to be notorious for finding ways to:

1. Argue if you raise the subject.
2. Overcharge.
3. ROYALLY screw it up.

There's a recent post: they messed up someone's transaxle and inverter, drove them to trade-in.

I can post a PDF instruction in a bit, but yeah it is dead easy.

 

Yeah, to DIY change transaxle fluid, you should have on hand:

1. The means to raise and level the car, say 6", safely.
2. (4) quarts or liters of Toyota ATF WS fluid. (don't gamble, stick with this). You'll need roughly 3.5 quarts/liters.
3. Replacement washers for the fill and drain bolts. (they're identical)
3. Ratchet wrench, extensions, and a 10mm hex allen key style socket. (male: the fill and drain bolts are socket-head cap screws). I'd recommend to have a long-handled ratchet, say 18": the torque on the fill/drain bolts is 29 ft/lb, and they will likely be very glued on by now. Just to be on the safe side: remove the fill bolt first.
4. Appropriate torque wrench, for 29 ft/lb.
5. Screw driver, pry tools and 10 mm socket, for removal of the engine underpanel. This is not mandatory, but make life easier. Wash out all the push-in fasteners when they're off, and coat the the small bolts with some rust-preventative. Note: two of the push-in fasteners are slightly larger than the rest, have grey-coloured heads. These are at the "oil change" flap. Good to mark them with a highlighter of some sort, and their location.
6. Funnel with 3' tube extension, keep tube diameter 5/8" or less (to fit in the fill hole). Snake it down through the engine bay from the top. You should have an assistant to do the pouring. If not: you can pour freely up to 3 quarts, then just pour 100 cc at a time, while checking. Stop as soon as it starts to overflow. Note, you can use a pump from below, but my take: this is needlessly complicated. Also, make sure the hose and funnel are free of other oils, and/or use it exclusively for Prius transaxle.

You basically drain-and-fill. When filling the level is correct when it starts coming back out. There's instruction in the Repair Manual to recheck level after a drive. I did this the first time and found it pointless; there was no change.

I've attached the Repair Manual instruction:

 

I did recently mine 47k milage and very satisfied with the result.While you change out gold plug on it.

Posted via the PriusChat mobile app.

 

loosen the fill plug before the drain plug.

 

How can we test if the mechanic did a good job with transmission fluid?

 

Tough to do, you really need trust. Did they use Toyota ATF WS fluid? The trick to getting the level right is to refill with the car level, until it starts overflowing, then just wait a sec till it subsides.

 

Great question. Aside from level, id agree with ML.

Really, aside from being cheap, I like to do as much as possible DIY.

Not really an answer and looking forward to seeing more on it.

 

To test the level you could raise/level the car again, remove the fill bolt, and splish-splash with a pinky, make sure the levels up there. But really begs the question: if you can do this, why not DIY the whole thing?

Again, where you are: