Replace "Transmission" Fluid?

I do recommend it. The failure mode for the transaxle seems to be overheating and baking the insulation off the Motor/Generators. By replacing the fluid, you remove suspended solids that may be causing short circuits and reducing fluid flow.

As a DIY, the parts should be about $40USD, my dealer does the service for $110USD. I have no idea what your dealer charges.

I like 50,000 km, then 150,000 km, then every 150,000 km as a service interval. So in my mind you are very ready.

 

I just did mine myself. Not a hard job at all. 2010 with 56,000 miles. Fluid
looked really bad.

 

Well then you should be all over this: about $40 for the fluid and a couple of washers, takes about an hour to DIY. You need to raise and level the car, drain the fluid, pour in fresh fluid till it starts coming back out (a funnel with 3 foot of hose extension is simplest approach to doing this).

Through the dealership, anywhere between $80 and $100 I wouldn't argue; any higher, I'd look into DIY, or dicker. Make VERY sure they're using Toyota ATF WS fluid. It'll take about 3.5 liters, so you need to have four on hand.

I would have done a first drain-and-fill about 180,000 km's sooner. Then every 60.0000 km's or so, pick your interval. The first one seems to be most crucial, the fluid most dark looking.

 

I recommend it also. There is a very easy DIY video on YouTube. You just buy the trans fluid, fluid pump, and hexagon key to open the drain bolt and fill bolt. Your car will drive like new! Might as well do the oil change altogether too.

 

Toyota says transmission fluid not need to be replaced.Is it true?

 

true. Lifetime fluid.

 

Every lubricant ever made needs replacing eventually. Every 100,000 miles is fine,

 

Toyota doesn’t actually say anything on the subject.

I would change it at least once, sooner than later.

 

Repair manual has instructions fwiw:

 

I go by this no matter what.

 

"Lifetime" usually means the life of the epa warranty.
It's easy enough to change and inexpensive enough that you should do it.

 

To be accurate, what Toyota says is that you need to inspect the fluid. And you’ll find that it’s really dark and in need of replacement, so replace it.

 

Do recommend replacing the fluid from the transactional as well?

Is that an additional 4 bottles?

 

There’s one “transmission”; Toyota calls it the “transaxle”. There’s a link in my signature with info on changing the fluid. If you’re on a phone turn it landscape to see signature.

 

A single unit that combines the speed/torque-converting "transmission" and the torque-splitting "differential and axle' is called a transaxle. That's what the Prius has, so that's what they call it.

 

The term "transaxle" has been used pretty much ever since front-drive cars appeared to denote the combination of transmission (of any type), final reduction gearset, and differential, all combined within a single case and sharing common lubricant. It's definitely not specific to Prii.

 

I just replaced my transmission fluid (155k) color of the old fluid looked like chocolate syrup. New fluid is like fruit punch red. There's no way it's lifetime

SM-N986U ?

 

"Lifetime" for care manufacturers mean the lifetime of the warranty....

 

I did transmission fluid replacement at 60k miles, 120k miles 180k miles and at 240k miles in my 2004 Prius. I had the old fluid lab analyzed each time. The first 60k fluid had significant silicon (from the sealant used in seams), metals (from the lapping in of the transmission gears) and had lost significant viscosity. That first change was necessary but should have been done earlier. The fluid from the later changes were in better shape so they could have been done later.

I did an ATF fluid change in my 2016 (killed by a Kamikaze deer) and 2020 Prii before they reached 30k miles and will do it again at 120k miles and every 90k miles thereafter. My dealer charges about $100 for the job.

JeffD