2016 Prius transmission fluid change

IMHO, it should be changed at least every 100K miles. Contaminate concentration builds up over time, chemical structures change through hot and cold cycling, age of fluid, to name a few. Let's face it, the OEM only cares about the car lasting past it's warranty period. That's their definition of lifetime, IMHO. Everything else attributed to their brand name is gravy.
If you do the change yourself, the cost is around $75 using OEM parts and fluid. I consider that cheap insurance every 100K miles.

Just my 2 cents......

 

Takes an hour or two. Four quarts of Toyota ATF WS and replacement washers will set you back about $50* USD. My preference is to do it around one year or 10,000 miles, but no time like the present. There's a link in my signature with some third gen tips, still relevant (on a phone turn it landscape to see signatures). Torque values are higher for the fill/drain bolts with gen 4, not sure why (see attached).

* That might be out of date, seems the price of the fluid has jumped of late.

 

Pay the premium price for the OEM fluid.
I normally would not make that recommendation BUT the ‘transmission’ in this car has motor-generators and windings.
The OEM stuff is proven to work.

The fluid is good for the life of the car WARRANTY.
Beyond that….. ???
There are issues of reputation but Toyota has already done the cost-benefit on that.

YMMV

 

The fill/drain bolts are "socket head cap screw" style, have a recessed 10mm hex pocket on the head. Don't be tempted to bust them loose with a 10mm Allen key, and even less so, a 3/8" Allen key (~9.5mm). You can get 10mm hex bit "sockets", and coupled with an extra-long-handled, swivel-head ratchet wrench it's a breeze. You need such a socket to use with a torque wrench too.

All of this is predicated on DIY approach. If you were to go into a dealership service department for this, tread cautiously. For whatever reason, dealerships may try to dissuade you from doing this, and if they do agree to do it, way overcharge. It's roughly similar in complexity/time to an oil/filter change, albeit a bit different. I used to say it shouldn't cost you over $100 USD at the dealership. Considering the Toyota ATF WS fluid price has inflated, say $125 at most.

 

Yep, I've changed ours every 6-years or 60,000 miles whichever comes first. (Just a drain and fill.)

You are way overdue, do it ASAP or pay to get it done.

 

I live in Okla City and a Toyota dealer in Midwest City quoted me $259.00 for a transmission fluid change on my 2018 Prius Prime Adv.

 

Easy $200 profit for under an hour's work, with 4 bottles of Toyota ATF WS (say $12~15 USD apiece, retail), and the drain/fill bolt washers (say $2 USD apiece, retail).

attached is the overly verbose repair manual instruction, and a pic of the tools involved.

 

I am about to do this. Could you please let me know the type of tubing you got? I see in Home Depot 3/8 in. I.D. x 1/2 in. O.D. x 10 ft. Clear Vinyl Tubing. Will that work? Also if you don't mind sharing where you got that funnel. Thanks!

 

2-2.5 feet should be more than enough hose. Possibly another foot, if you don't want to lean into the car too much. The longer the hose the bigger the mess. Also more chances of it popping loose, since you'll be lifting it more to get all the ATF down the hose.
Any funnel that will snugly fit the 3/8 ID. This is going to be a gravity drain. You can add a zip tie if your insecure.

Hope this helps...

 

In my signature (on a phone turn it landscape to see signature) there’s a transaxle fluid change link, with info on max tube OD, and length. For length a simple strategy is to start with a generous length (say 5 feet), run it down through the engine bay to the fill hole, then trim to suit.

FWIW, I think I settled with three foot hose extension, for my Gen 3, with that particular funnel, would have to check. But again, just initially cut it generous, then trim, is prudent.

I got that funnel at Princess Auto (Canadian store, sim to Harbour Freight I think). Not seeing it now, but this looks similar.

But again, a Canadian link, but a fairly common item. I would look for something online, from a nearby brick-and-mortar location, then go there, taking along an inch or two of your tubing purchase, trial-fit it on prospective funnel.

FWIW, most any household plastic funnel with suitable taper fit nozzle would work. Good to label it, use it exclusively for Toyota ATF WS; Toyota is quite adamant about using just that fluid.