Transmission oil Prime 2018

You haven’t posted enough.

 

The ATF-WS ran about $8 or more per quart. You might find a real deal, but I'd be leery of it if it's super cheap. It sounds right, but I've only done the fluid change on my Gen 2 and Gen 3.

 

That doesn't look like the Toyota bottle to me. I'm also thinking that when Toyota recommends regular changes it's not really all that "Lifetime".

Can you get some from one of the Toyota dealers? The US dealers sell it in the parts department.

 

The Car Care Nut has a YouTube video on that very thing.

The short story is you either change it regularly or not at all. I think the recommended interval is 60K miles.

It should be like all the other parts they have. I don't know why they wouldn't sell it to you, unless it's something specific to Denmark.

 

But unlike a regular automatic transmission, there is no oil shearing because of a torque converter and no detritus from friction bands/plates because there are none. Beside the coating of the stator wires (which you have a bigger issue if it detaches from the wires), it's all metal. And any metal shaving is being caught by a magnet at the bottom of the transmission casing. A magnet that you can't service so even if you change the oil, the shavings will stay stuck to that magnet.

The only reason I can think of to change the transmission oil (that even Toyota says doesn't need to be changed), is if you pull something heavy and overheat the motors, hence the oil too.

Check the Weber Auto video of when he's reassembling the Gen 4 transmission to see what's inside it. I don't think there is even a filter. At least, I don't recall seeing one.

 

Lifetime to a manufacturer is 100k to 150k miles.

 

What about manual transmissions?

 

Manual transmission oils usually contain additives like the one that helps with gears' synchronization by making the conical surfaces of those gears "grab one another". That grabbing allows the gears to spin at the same speed before being engaged. With time, these additives deteriorate and makes shifting harder. Something the Prius transmission does not have. It's such a simple transmission.

I don't know though if the transmission uses some non ferrous metal, like brass, which would keep circulating within the transmission until the oil is poured. I doubt the bearings are made of brass thought since they are not subjected to corrosion. The casing shouldn't deteriorate either so I don't think there should be any aluminum in the oil. What else? Copper wire from the stator wires to the casing? I doubt that copper will deteriorate either. What else?

 

This was parts or service department? Just go to parts, buy 4 quarts/liters of the correct stuff (Genuine Toyota ATF WS), plus the fill and drain bolt replacement washers.

Transaxle fluid change link in my signature is gen 3 specific, but mostly applicable to 4th gen (to see signature on phone turn it landscape). Repair Manual info for 4th gen:

 

The fluid in manual transmissions tend to be more heat tolerant than ATF. Toyota may not have needed to add additional cooling if such was used.

 

No problem.