IS IT REALLY A LIFETIME OF A THING?

1) you don't have to replace it, but you may want to.

2) correct.

3) color is not a good indicator of quality.

4) it means they've designed it in such a way, that the requisite percentage will go beyond the length of warranty, so it is a good marketing strategy for them.
hard to believe that any prospective buyers would look at something like that though.

5) yes, many. see your aforementioned bob wilson, for instance.

 

Having drained and filled it on our 3rd gen 3 times now, and just judging from color of the drained fluid (which maybe doesn't mean much):

first drain, at 12 months and roughly 15K kms: drained fluid markedly darker
second drain, at 36 months and 40K kms: drained fluid somewhat darker
third drain, at 72 months and 64K kms: drain fluid almost indistinguishable from new

 

No, and would there even be a spec, what with Toyota saying lifetime?

Darker infers to me more particles, and accordingly, for about $40 in supplies, a quite early pre-emptive change is worthwhile.

I'll attach the repair manual instruction, very straightforward. I don't think they mention, but proper fill is predicated on the car being level, presumably also raised.

You basically achieve the correct level by adding the new fluid till it starts flowing back out (with car level). There's instruction to recheck the level after a drive. IMHO this is onerous and unnecessary. I did the recheck, a day or two after my the first drain-and-fill, and the level had not budged.

Also, there's various methods to get the new fluids in, shown in videos. By far the simplest is to just use a funnel with hose extension, from above. Pour 3 quarts/liters quickly, then go carefully, shot at a time with the 4th, till it overflows.

 

i think bob came up with a number of metals that concerned him. i believe he did a 5,000 mile change, and then longer after that.

 

Really, what is a "lifetime"? As an auto engineer it would seem like you would know this answer better than we plebeians.

The transmission fluid lasts for whatever definition Toyota is using for "lifetime". Maybe that means "until the warranty runs out".

I talked to the fellows at the taxi garage. They run a lot of Prius and Prius v. This particular company has many Prius with over 300,000 miles.

I learned two facts from the mechanics:

1] They have never replaced a Prius transmission
2] They don't drain and fill them, either.

They do drain and fill engine and inverter coolant every 120,000 miles.

 

If you search on Prius Chat and Bob is The Oil guy, there are used oil analysis of it. The general consensus based on these is: first change at 30k miles, then every 60k thereafter. The first change is earlier due to more particles from the initial break in.

I bought my Prius with 60k and didn't find out until driving it for a while that I needed to change this oil, so I changed mine at 80k and will change it again at 140k. My oil was significantly darker than the new oil, not black, but a dark red.

Toyota calls it "lifetime" likely because it will make it to 175k miles in the vast majority of cases. However if you want to go past 200k, changing it is a must.

On the PC forums, I don't know of any cases of transaxle failures of those who did change their oil, and likewise it seems that all transaxle failures occurred in cars that did not have their oil changed. But that's very anecdotal considering that 95%+ of Prius drivers don't change their transaxle oil because of what Toyota says about it.

Pretty much any fluid in a car should be changed after about 8 years or 100k miles.

 

These quotes pretty much sum up the debate. It pretty much comes down to an (unquantifiable) risk and peace of mind. I've been following Priuschat for the 8 years that I have owned my Prius. My conclusion is that power sharing device ("e-CVT") failure is rare and I am comfortable taking the risk. I respect those that prefer to change the fluid.

What tips the balance for me? I wouldn't change it myself and I hate to pay for anything that I'm not convinced I need. I get it that if you are doing it yourself it is not much time or money.

 

My take: the lower the cost, and the easier the task, the less I fret about the need to do it. For $40 and the complexity of an oil change, do it once or twice.

 

the problem with the tranny lifetime as defined by warranty is that it's only 3/36 i think. if that is all it is designed for, i think i'll change my oil.

 

I don't think that is a logical conclusion. It would seem that the consensus is that the car's lifetime is in excess of 150,000 miles, especially as Toyota's CARB warranty is 15 years or 150,000 miles. I'd go with Kevin_Denver's 175,000 miles as an absolute max interval, but think the first change at 30,000 miles and then every 60,000 thereafter is the safest bet.

Here in NZ it seems a transaxle oil change has been added to the 90,000 km (~56,000 mi) service, as they just did it without me asking, and I have seen it also performed on another Prius at 90,000 km at a different Toyota service centre in a different city. I haven't asked to confirm, but the implication is that Toyota NZ has provided the direction to their service centres.

 

at least it's not sealed...

 

Maybe the expression "sealed" just means no dipstick?

 

I'm sure everyone here will agree that NOTHING LASTS FOREVER.

"Lifetime" Warranty/Part/Fluid is all marketing: cheaper operating costs b/c it will last "forever," as many mistakenly believe. Anything that is used will break down and fail, at some point in the future; if you change cars frequently, you will likely never experience this. Even something that is not used, but exposed to the elements will breakdown too, unless it is well protected against the elements; but that exterior protection will fail over time too. The best explanation of "Lifetime" to me was by a mechanic, who said something to the extent: when the part fails, that was the life of the part; quantify it however you want: years, mileage, or both.

I may be the only known person here on PC, to have a failed/failing transaxle replaced not under the 5yr/60,000 mile Powertrain Warranty, but the longer Emission Warranty, due to California being a CARB State w/ the longer 10yr/150,000 mile warranty. ATF fluid changes ARE Required. | Page 24 | PriusChat

• Post 473, pg24- pictures: of old vs new fluid at second 15K mile drain/fill, super strong non-OEM magnet transaxle drain bolt, Bob Wilson & Prof Denenberg ATF-WS used oil analysis study link
• Post 482, pg25- Bob Wilson, sees 5,000miles as the first optimum transaxle fluid change, if the car is new.
• Post 483, pg25- description of the sound transaxle was making.
• Post 497, pg25- Professor Denenberg best says it: "You can't really tell fluid condition from the color, it takes a $25-$30 lab test." Although people will still do it because of engine oil changes; new=clear-ish light golden color, old=black in color at next oil change interval, at least w/ conventional motor oil.
• Post 514, pg26- Contradictory Brake flush recommendation. Highlander Hybrid=NO, Lexus RX400h (a pricier Highlander Hybrid)=Yes.

The science of UOA (Used Oil Analysis) can't be argued. If you don't keep your cars long enough, you may never need to be bothered with a drain/fill on the Prius. But for the small cost ($32 for 4qt of ATF-WS and 2 crush washers, or $100 at dealer), good preventative maintenance. You would not believe an auto manufacture, if they said the engine oil is a lifetime fluid, just top off as needed? ATF-WS is a specially designed lubricant for certain Toyota transmissions/transaxles; yet some people ignore science and logic (UOA and the fact that no lubricant lasts forever). Also, Toyota gives contradictory Brake Flush recommendations: Toyota=NO, Lexus=YES.

It is ultimately your car. Spend or don't spend as you deem fit.