Gen 4 Prime ATF drain plug

Hard to judge from your pic; here's the ID from the Repair Manual (full instruction attached). Seems very close to the split-line between transaxle and engine.

 

Attached.

 

Yep, good job....I was pleasantly surprised at Toyota engineers for making this maintenance so easy....not much harder than an oil change! (For me, the hardest part was getting those darn drain plugs to break free...someone needs to tell the factory installers the torque is 37 ft/lbs not 400!!!!)

 

And dealership charge through the roof, most recently $400 USD quote here.

 

Exactly! My dealer charges the same for a much-more-difficult V-8 Tundra as a Priis...$310!!

 

Last time I bought up here Toyota ATF WS was around $10~11 CDN per liter. But that was a few years back, and I know Toyota motor oil has really gone up.

 

My 2008 Corolla had a dipstick so it was super easy to see the condition of the transmission fluid....bugs me how we don't have that luxury now. (Easier to fill it, too.) My co-worker has a BMW and it doesn't even have a dipstick to check the engine oil....how dumb is that???

When I changed my wifes 2017 Prius transmission fluid at the 5-year point, it only had 29,000 miles and wasn't very dirty. I've heard of some folks changing it out every 2-years but transmission guys say that's actually not good because it does need a little bit of friction in there to help everything move around better. (I just do every 5-years or 50,000 miles, whichever comes first.)

 

My 2008 Corolla had a dipstick so it was super easy to see the condition of the transmission fluid....bugs me how we don't have that luxury now. (Easier to fill it, too.) My co-worker has a BMW and it doesn't even have a dipstick to check the engine oil....how dumb is that???

When I changed my wifes 2017 Prius transmission fluid at the 5-year point, it only had 29,000 miles and wasn't very dirty. I've heard of some folks changing it out every 2-years but transmission guys say that's actually not good because it does need a little bit of friction in there to help everything move around better. (I just do every 5-years or 50,000 miles, whichever comes first.)

 

It's an ATF, and the pre-gen4 Prii don't have an auxiliary cooler. So the fluid gets 'burnt'. But it isn't an automatic transmission. The fluid doesn't have to work as an hydraulic fluid. It just lubricates. It getting burnt likely has no effect on its lubricating properties. The addition of the cooler in the gen4 seems to be more for towing that is done in other markets.

Toyota should have used a mnaul transmission fluid for the transaxle, but the ATF was on hand and low viscosity for efficiency.

 

Ah, something I am due for our 20PP too ?
I am familiar with the normal -partial flush-refill and repeat (2-3 times) : it this what we are doing here ? any DIY linky?

TIA,

 

A single drain gets maybe 90%, no need for multiple drain/fill procedure. I wouldn't do that with a conventional automatic either; just periodically drain/fill, at a more frequent interval.The only time I'd do multiple drains and fills is in a contamination case, say you accidentally poured motor oil in (I did this one time, with a previous car...).

DIY linky attached.

 

Thank you Mendel... I will gather fluid and get it going ...
My pass Ody (312k, still going) which needs -regular- tranny flush- ... for some reason, I totally forget about the 20PP

EV-

 

There's a link in my signature regarding third gen transaxle fluid change, primarily DIY tips, and it's mostly relevant for the fourth gen I'd think.

One thing I noticed with the fourth gen Repair Manual instruction, they really go on about keeping it sealed as much as possible, comparing to third gen. Maybe a nervous engineer. One thing I glean from that, plus a Toyota document on ATF WS, is that the fluid used should be from freshly opened bottles. I wouldn't go nuts, just drain it, get the new in, recycle any left over.