ATF fluid changes ARE Required.

Thanks to those who chimed in for my request to summarize this thread. I didn't mean to throw the question to you all to get a quick and easy answer without due diligence in my part. After reading many threads on other regular maintenance topics, it was clear to me that the consensus is that to stick with the official Toyota maintenance schedule, EXCEPT this ATF fluid change. I didn't know why, and I wanted ask why that is to those who are so passionate about this issue.

I am all for saving money by DIY, but I don't have place or equipment to work on a car safely raised. So, my DIY capability is very limited. I purchased engine air filter and cabin air filter from amazon, so I will definitely replace them DIY. That leaves only oil and filter change for the 30K maintenance that really has to be done. I have to take my car in to have the winter tires changed soon, so I was thinking to have the shop change oil and filter and have other inspections performed at the same time. I don't know what they will quote me for ATF drain and fill, but if it's only $90 as many on this thread has been suggesting, then I am considering doing that.

 

Yeah listen to their response when asking about the transaxle fluid change. I'd back off if they give you the "gears", lol. Read the atfachment I posted; it is dead simple.

 

Jeff,

I agree with you on the technical principle that changing the fluid is probably a worthwhile activity. In the 120k miles that I drove my 2010, I did it 3 times, I think.

However, I think "selfish" is a bit preachy and self-righteous. I don't (and I'd argue that you don't) owe anything to anyone...

And, i'd also argue that it is not "easily" done DIY. It was a pain in the behind, and on the first time, resulted in an ATF bath (of course, that could just be my own mechanical ineptitude... )

If you've changed the oil, it may increase the durability and hence the market value if the purchaser has taken the time to educate themselves. Records of such maintenance should be kept, and offered as a negotiating chip for a higher resale. Similarly absence of such records tips the negotiating leverage in favor of purchaser. That's market dynamics, not "selfishness" or "graciousness", which are more philosophical, eh?

I question whether there are examples of 200k prii without ATF changes? Are NYC cabs subjected to regular ATF change? (I don't know).

I guess i'm just full of snark today... nothing personal.
Eric

 

One negative: people who change the fluid with an alternative to Toyota ATF WS. While this may be ok, it's irresponsible to future owners.

 

Let me ask this question. Are there any reports of prevalent transmission problems on Prius that had no ATF changes?

 

Nothing should ever be decided without some testing to verify what others have seen. I see you live in New England, are you still seeing freezing weather at night?

If not, it does not matter. But when freezing weather returns, do you have a shallow grade near your home?

If you have a shallow grade near your home, wait until the fall or winter when you get freezing weather. Carefully drive your car to a spot; stop the car, and; put it in "N" and see where the car stops rolling. Do this over 2-3 mornings. Then try the same test when you get home when the car is warm. You'll see there is a difference. Then comes the moment of truth.

Change the transaxle oil (with a sample of the old oil) and repeat the roll-down test. This will let you tell us if cleaner oil reduces transaxle drag. I look forward to your results either this year or in the Fall.

Bob Wilson

 

Toyota ATF WS is widely regarded as total crap, I've gone away from it on all my cars. Does the Prius use standard ATF fluids? I'll probably get some Amsoil or Red Line, but wasn't sure what most people were using.

 

Ha, ha. I like your suggestion a lot. Though there are few practical problems. I can clear the freezing weather part easily. Our temp hasn't reached above freezing for days and not anytime soon. Problem would be finding a shallow grade near enough my house. It will be at least a few miles away from my house, so would a few miles of drive warms up ATF to affect this test? More of problem would be to find time when there are no other cars on the road. Even if I managed to compare cold vs. warm ATF, since you are suggesting to compare that results with after the ATF change, by then I have nothing to decide. I have ALREADY changed ATF for whatever the cost and trouble I had to endure Plus, by the time I change ATF on my car, our freezing temp will be gone, and my Prius will be with all season tires, so too many variable changes for comparison.

So, are you implying changing ATF will reduce transaxle drag, and it will increase fuel efficiency?

 

Toyota cautions strongly to only use Toyota ATF WS.

 

of course they do - you can check BITOG or toyotanation to see the problems with WS.

 

One more reason I never buy used.

 

then you're wasting a whole lot of money lol - that's okay though, personal choice.

the problems with Toyota's WS fluid are well known -

forum won't let me post links as of yet, but a short google search will provide you all the info you need to know about it.

been running red line trans fluid in my rav4 (spec'd WS) for quite some time now, trans feels great. run red line d4 in my corolla for the last 100k miles or so, absolutely flawless. once i get the prius, will run d6 or amsoil's atf in the trans. IDK what your experience is with lubrication engineering, but i encourage you to check out the wealth of knowledge on BITOG :thumbup:

 

Here are my results: 2003 Prius - Cold Weather and Transaxle

I prefer: run tests as best I am able; document the results, and; share with the community. Near as I can tell, the worn transaxle oil is especially sensitive to cold.

If I didn't have a shallow grade for a roll-down test, the next best would be to instrument the transaxle with a temperature probe via the oil filler plug and measure the warm-up rate. Run enough 'old oil' tests to establish a baseline; change the oil, and; run the same baseline test to see if there is a measurable change in the warm-up rate. My expectation is it will take longer to warm up because it does not waste energy heating the transaxle.

Another approach, block the car and raise one wheel and let it cold-soak including the replacement oil. Lift one wheel; use a hand-drill with a kill-a-watt meter to spin the wheel, and; measure the wheel rpm and electrical power to the hand drill. Then drain and replace the oil and repeat the test. The difference in rpm and power needed to spin the cold-soak wheel will give a direct readout of the drag reduction.

Now if you are careful to save the old oil, replace the new oil with the old oil and confirm the cold-soak drag returns. In engineering we call this an A-B-A test that makes sure the change in performance is correctly associated with the change in the independent variable.

Bob Wilson

 

Just ordered Toyota Genuine WS Automatic Transmission Fluid! To make the shipping free, I had to order one extra bottle, but at $7.08/qt, I am not complaining.
Toyota Genuine WS Automatic Transmission Fluid - Walmart.com

 

Did you check price at dealership? Up here it was $9.14 (Can) per liter. You can skip the washers if it doesn't stress you too much, but dealership should have them. My invoice says p/n: 90430-18008 for the (identical) washers. Again, torque is 29 ft/lb, for both.

 

Yap. Dealer quoted me $9.20/qt. Not too bad, but I have to drive 1 hour to get them. Walmart will deliver it to my door step free. Thanks for the p/n for the washers. I will look for them online. By the way, the service manual page you attached on your previous post is for 2010 Prius, will it be the same for 2015? I am going to print a copy and bring it with me to a shop.

 

And that is somewhat different than what started this thread, which is changing it at 30K.
Some even carry it WAY overboard and change it at 10K and every 10K after that.
Totally ridiculous.

And while the lab tests on your used fluid might appear compelling on the surface, it actually PROVES nothing about the life of the transmission.
I wonder how many cars are on the road today with over 100K miles on them and the tranny is still happy as a lark ??? Can't prove that either.

 

I agree that doing it too often is unnecessary and costly, but one early exchange by about 30k miles is worth doing to get out the excessive metallic wear particles as the gears lap in and then extend to every 60k miles thereafter

JeffD

 

The instruction is still applicable, any 3rd Gen. pip too.

 

Found the gasket on ebay. $8.08 for 10 gaskets. I only need 2, but this was cheper than buying at Amazon $4.05 for one gasket!!! I wonder what dealer would charge for this???
GENUINE TOYOTA LEXUS DRAIN PLUG GASKET OEM SET 10 90430-18008 | eBay