Should I change the transmission fluid at 25K/3 years of ownership, or not?

simply because it's wasteful. In this instance a new user has been told that swapping out this fluid is "highly recommended" without really identifying that it's highly recommended by a very narrow cross section of owners and based on nothing more than "feeling" that it has a benefit. The interval is arbitrary, and without knowing the actual minimum requirements for fluid in the transaxle, UOA is meaningless.

No harm done, oil in oil out. There is no pattern of fluid related transaxle failure in these vehicles, but let's say hypothetically it's one in 15000(seems high to me). Thanks to the efforts of users on this board, if you get 100 users to swap out fluid early, and just one of these users strips a bolt, improperly fills transaxle, improperly installs the plug...then the risk of following priuschat advice will far outweigh the risk of transaxle failure. That's a worst case scenario...at best you're wasting 400quarts of TA fluid for..."cheap insurance"?

 

They were thinking a trans fluid replacement for a Tundra truck which uses same WS fluid also and is a real pain in the &ss. Requires Toyota Techstream software and specific temperatures of the fluid. Be wary of that place as they are clueless or maybe just the Service Writer was clueless.

Prius is very very easy a dump and pump. Just like any other manual gearbox.

 

It's not wasteful to me. That's about all there is to it.

If you don't agree, that's ok. I don't agree with your side. That's ok, too.

 

"They all don't?"

Who's they? Uninformed service writers? If your quoting this site we all know SW's are clueless about our cars.
That's fine but they don't have to pay for my car when it breaks down do they? And your not going to either are you?

You've been here on this site for all of 30 days and admonishing people to not change there fluids (why I don't know its not your money) after we have seen many posts in the last 5 years here about failed trans due to lack of maintenance. And what you quote is rubbish.
Btw, this is a car forum. We work on and take care of our cars here. Must be your first.

You clearly don't understand the connection between fluid life and gear wear. You clearly have never torn down a poorly lubricated machine. You clearly have never torn down a very well maintained machine. If you did you would understand the difference and how it behooves you to do all you can to keep the car running well and off the dealer rack. All that requires in a Toyota is you pour some fresh oil in the car once in a while.

And across the span of 150,000 miles I'll compare 20 quarts of WS against a blown trans both financially and wastefulness any day.

5 Changes of trans fluid= WS= $230 home install or dealer= $600 over 10 years of driving.

Used Trans(if you can find one) + labor= $3500. And that's a used trans price. Dealer is about $6000.
Of course that doesn't include the incredible hassle & $$ of your car down for days possibly weeks.
And possible collateral damage the car could incur just sitting or getting worked on.

How's that for waste?

If we could pour something in our Hybrid batteries to keep them going in great shape for 10 years we'd be lining up to buy it and do it. It would be the biggest topic on this site. But you'd call that wasteful too I'm sure.

Me? I'm going to sell my great working and very well maintained car at 150,000 and make some money.

 

If you DIY you need:

* (4) - liters Toyota ATF-WS fluid (or qt's in the US? Either will do, it'll take around 3.5 liters)
* 10mm male hex drive
* torque wrench, extension bars, braker bar (the more the merrier)
* (2) - replacement washers for the drain and fill bolts (which are identical) (in a pinch you can re-use, but...)
* funnel with attached 3 foot hose (or some sort of pump system, but funnel works fine)
* Means to raise the car and get it level (and safe!), say 10" raise

I could post the instruction from the manual tonight. Not much to it, basically the drain/fill bolt torque spec, and the fluid level spec, which is basically to fill till it starts coming back out, then just wait it out till it's just an isolated drip. That's with the car level.

I would suggest to take the plastic engine underpanel completely off for this. It's a 10~15 minute chore each way. Some of the fasteners are different, so you should keep them organized.

 

For our 2009, torque both bolts to 29 ft lbs. The tube on the funnel only needed to be about 18" long, and the fill level was "just below the fill hole." I used "to the fill hole." I wound up using about 3.9 qts of ATF.

Both plugs required a breaker bar.

 

Something that's worth repeating when discussing transmission fluid changes it to always remove, or at least loosen the fill plug before removing the drain plug. If you drain the transmission first, then find out the fill plug is firmly stuck in place and you can't remove it, that is really inconvenient. That doesn't happen often, but if it does happen.

 

Apparently NOBODY in the Toyota corporation recommends routine maintenance of any kind on what is basically a sealed system, but YOU know better than the team of engineers who do nothing but study these TA's every day. I forgot, nobody knows more about these cars than "internet experts" with their dataset of literally dozens of cars! (I hope I'm being condescending enough, your tone is tough to match!)

If what I quote(which, ironically, you noted above is this forum) is rubbish, then SHOW ME, EDUCATE ME, Identify the problem and show me the benefit of YOUR fluid change intervals. no? For all my "admonishing", nobody is showing me any incidence(not incidents) of fluid related failures in genIII prius.
I would say the days of "working on cars" is well behind us. What goes on here is recreational maintenance. If we're over 40, most of us owned several vehicles which required actual work. now, they simply don't. Wrench owners simply feel the need to identify problems where none exist. previous weekend mechanics are reduced to changing liquid instead of head gaskets, valve shims and timing chains. From transaxle fluids this group will next find a critical fault with brake and coolant fluids. For all this diddling with liquid, the thing that will likely bring the car to it's economical tipping point(cost of repair/value) is the hybrid system/batt itself. I "admonish" people not to change fluids because some users here are misleading newbies into performing service that is not required, recommended or of any demonstrated benefit!

Toyota is kind enough to study the effect of fluid life and gear wear(I guess they clearly don't understand it?), and they then give you a schedule for pouring in that fresh oil! ta-da! Their millions of cars of experience also told them was to seal the transaxle and not even give you a way to check the fluid level! if it's so obvious that fluids require changing at (ha) 30kmi, why don't they even recommend looking at it!? what ARE they up to?(rhetorical)

um, that's $600 of waste and 20q of oil for what people in the oil change business used to call "cheap insurance", which it is not. You convince 50 users to do the same that's $30k and 1000 quarts of oil, to save 50 transaxles that wouldn't fail to begin with, even if you prevented one failure that would a collective $24k wasted. your example is false economy because you can never show that any of this small sample size would have failed. Now, as the number of changes increase, we approach the ratio (1:xxxx) of DIY fluid swaps before someone's car falls on them because people here are advocating jacking up both ends of a car to get it level(seriously?). How many times can DIY'ers jack up both ends of a vehicle before one falls? 1:100? 1:1000? which fails first, a DIY'er or a transaxle?

If we could pour something in our batteries that somebody could DEMONSTRATE kept batteries going and in great shape I'd get in line to get some! What's more likely is that somebody here will decide that the electrolytes in the batteries obviously need to be swapped out(to hell with what those morons at toyota think), crack their battery open and change it...then post here "Highly recommended that you change this if you care about your car, I changed mine and my battery hasn't failed yet".

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funny, I am too, mine will probably be closer to 200kmi, and I'll have saved roughly $1500 and 100quarts of fluids. Fluids that have to be manufactured, transported, stored, transported home, swapped, transported to recycling center, transported to recycling plant.​

I came here to get info from a collective knowledge base. I half expected that Prius owners would be A) thrifty and/or B)Green. what I find is that this particular forum is home to many who are neither. For economy or ecology(eco mode) we try to squeeze every mpg out of our cars, then voluntarily waste money and resources. I don't know what I expected on a maintenance forum for a car that basically requires no maintenance....​

 

I'm not a real mechanic, and I don't play one on the interweb. I simply do as much work as I can on all the things that are not too advanced for my skill set.

Lulz' experience is exactly the reason I do so. That, and there's no way I could pay to have done all the things that need done to a house and six vehicles. I have skills, space, and tools. What a life!

 

haha I don't know whether this proves my point or ed's!

 

If you believe Toyota tells you absolutely everything you need to know, at every level of ownership, and owner intelligence, I have nothing else to say. It's beyond hope.

Either you are arguing to be arguing, simply don't understand the concept, believe petroleum is much more precious than do I, or believe too deeply in the wisdom of Mother Toyota. We are all competent individuals who believe an early lube change is not a problem and may in fact be of value. There have been some indications that the ATF can get pretty toasty before the recommended interval. In some vehicles. Under some circumstances. Thus, it can be beneficial to change it. Are benefits of this early change quantifiable? Maybe, maybe not. Depends on your proof level. Mine has been fulfilled.

An early change can only be a benefit, and frankly I don't give a shinola about wasting 4 qts of lube. Or hundreds of quarts total over all Prius owners. Or whether Toyota thinks is a problem or not. That's somebody elses bugaboo, not mine.

There's no way the two sides are ever going to find common ground. I respect your desire to keep your wrenches clean and lined up neatly.

Happy motoring to all.

 

well, I do enjoy offering an alternative POV! And I understand that people who believe in early changes will continue to do so, and it really doesn't bother me a bit, and I've owned very big, very thirsty vehicles that let me know when it was time for an oil change...and they were frequent! my vehicles owned since 05 have all had very long fluid change intervals. I've stuck to manuf. fluid change intervals for over 200k with no problems whatsover, and I anticipate the same from the new prius.

Happy motoring indeed!...oh, and my wrenches are always in a messy pile

 

Lulz, one thing I do know is I'd look into a different dealer for service. Or at least call back during a different day or time of day to see if you get the same incompetence and if you do then definitely look at a different dealer if possible.

 

Mileage, load and operating temperature. The transmission is well sealed with no combustion products to deal with so time by itself isn't much of a factor.

 

Just a head's up: I posted a pdf snip from the manual (specifics for transaxle fluid change) in my posting up the page. Not much to it really: torque spec. for the 2 bolts, and level spec.