ATF fluid changes ARE Required.

Ah, but I have the advantage of two driveways, one slanted and one level.

 

Did not see any oil analysis results on new-unused Toyota ATF WS fresh out of the bottle. Without doing that, you can't be certain what metals may be included as part of the ATF WS formulation that might show up as 'wear metals' in the used oil. Since there seems to be little or nothing published about the Toyota formulation, having some baseline on new fluid would be a good idea. As already mentioned, the Prius tranny is a type of gearbox. Gear lubes have been know to include metals such as aluminum, magnesium and silicon as solid film lubricant. Not that Toyota includes any - we just don't know. Without knowing any of that regarding new fluid, lab results on used oil can't be interpreted with confidence.

 

When analysis costs almost as much as the replacement fluid, I prefer to just do a preemptive change, every 2~3 years.

 

The "virgin" type WS analysis was done many years ago and published on PC. Attached is the summary of analyses done on my 2004 Prius at 60k, 120k,and 180k miles. It includes the results on a virgin sample.

JeffD

 

Great! Thanks.

 

Funny that the Toyota procedure doesn't mention draining the fluid. I guess they assume you'll do that when you pull the drain plug

 

I think you misunderstood me. The Toyota procedure from the maintenance manual for replacing the ATF tells you to pull the filler plug, pull the drain plug, then replace the drain plug, but it never says to let it drain, or put a pan to catch the ATF, etc.....

 

After the first time you'll catch on real fast, lol.

That said, the Repair Manual is a very terse tome.

 

Yup. Pull the fill plug first, because if, for some reason you can't remove it, you can stop the procedure. But if you drain the fluid and then you can't open the full plug, you are in trouble.

 

Just for laughs, here is a FAQ from Toyota FAQs | Send Questions to Toyota Customer Service

"The transmission fluid does not need to be replaced unless an inspection shows it has become necessary." Here, Toyota admits that it could be necessary to replace the WS "lifetime" transmission fluid.

Indirectly, Toyota admits that WS ATF does not always last the lifetime of the vehicle.

Furthermore, it is implied ("it has become necessary") that Toyota requires replacement of the WS ATF only after it has already degraded to the point where replacement is obviously required. (That is not exactly my idea of "preventative" maintenance.)

So I agree with the title of this thread: "ATF fluid changes ARE Required". They are required by Toyota. And several laboratory analyses have shown that WS ATF does sometimes become exceedingly degraded long before the end of the lifetime of the vehicle.

But ...

Toyota has still failed to specify, whether to its customers, or to its mechanics, exactly how to determine when "it has become necessary" to replace WS ATF.

 

No doubt, this would become obvious, after a transaxle failure. Otherwise, they would NEVER check it, because it would then need to be changed. Every time I have had it done, I get the perplexed look from the Service guy, followed by, "You don't have to change the fluid, it's lifetime..."

 

Now there's some great advice!

 

Agreed! I changed mine for the first time today (65k miles), and I needed a breaker bar to get the plugs loose. The top one is harder to get to, so I made sure I could break it loose before I removed the drain.

 

Dealer for me if I can talk them into it for the right cost. I can't crawl under cars on jacks or ramps anymore.






Merged. PLEASE use multi quote as we've been merging a lot of your back to back posts.

Make sure you have the right hole.

 

OK, my 2015 Prius is due for 30K mile maintenance. I read here a lot of comments on ATF drain and fill at this low mile even though that is not listed on official Toyota maintenance manual. This thread is way too long to read from the beginning to the end. Can someone summarize what is the consensus of the Prius owner community on whether it needs ATF change at first 30K and every 60K after that?

 

Others probably won't like MY summary:
Do you think you might keep this car for something like 20 years and 300K miles ??
If so, doing extra preventative maintenance might make sense.
But for the average owner, it is just a waste of time and money.

 

I agree it's a long thread, and I don't mean to be too snarky, but are you really admitting that you are too lazy to read and asking us to do your thinking for you?

How about if you read as much as you can, and draw your own conclusions??

I apologize in advance for the short tone.

The general consensus is that it could be changed early - like 5k or less, and then every 30k - 60k thereafter. (Subject to various opinions, each defended with religious zeal)

 

Sam,

You are correct that "Others" will object as it is selfish advice. We owe the next owner a good maintenance record so that future problems are minimized. It was my lab tests on ATF in a 2004 Prius at 60k, , 120k and 180k miles that convinced a group of early Prius owners (including several experienced engineers) that regular maintenance of the ATF is worth doing (my dealer only charges $100 each time and it is easily done DIY).

JeffD

 

Yeah go for it. If you get resistance from the dealership, or they're asking an arm-and-a-leg, or spinning tales about how complicated/tricky it is: try another delership, or an independant, or DIY.

Maybe just go straight to DIY, if at all possible, likely safest. And do not get talked into alternative fluids, just stick with the spec'd. TOYOTA ATF WS. You'll need 4 quarts or liters (the transaxle should take about 3.5).

The correct level is achieved by having the car raised-and-level, filled till it starts coming back out. Drain and fill bolts are identical, it's best to replace both washers, and the torque is 29 ft/lbs. The simplest way by far to get the fluid in is funnel with hose extension. There is nothing complicated, about 90% of the fluid drains, no more complicated than an oil change.

It will take a couple of hours, cost about $40~45 (including exorbitant priced washers). Weigh the likely benefits against that, your call. I did first drain-and-fill at the one year mark, with around 15K km's. It was by far the darkest.