Changing Transaxle oil

Changed the Prius the first time at just under 10k - fluid was already dark. Changed again at 40k and the fluid was dark again. I think it may be similar to brake fluid - [ame="http://en.wikipedia.org/wiki/Hydroscopic"]hygroscopic[/ame]

 

Re: my PSD fluid after ~50.8K miles

Yeah that's a pretty fair price cwerdna.

Your fluid look similar to what mine looked like when I changed it recently (at 60k miles).

 

I changed mine at 5K miles and here is the used fluid in a plastic bottle:


As you can see it's pretty dark, only a tiny hint of red. I think the blackness is actually a good thing: the oil is doing its job carrying away the fine metal particles.

 

I am new to the board. Thank you, everyone, for the info on the tranny fluid change (and on all the other interesting topics on here). I just had a Jiffy Lube quote $370 to change the fluid, hence my Internet research.

Quick questions: why can't you drop the pan? It seems to me that most of the contaminants would be at the bottom of the pan and need cleaning out. Also, the dealer said they don't recommend flushing the tranny fluid after 100k miles. Any reasons you know of, or are they just misinformed?

 

The Gen II and Gen III cars have neither pan nor filter. Although I'd never let Jiffy Lube touch any vehicle I own, that quote sounds much too high. Changing fluid on a Prius is actually easier than on a conventional car, because you only need to remove two plugs, drain, and refill. If you prefer not to do the work yourself, take it to a Toyota dealer or to an independent mechanic who specializes in Priuses. The going rate is less than $200, and typically closer to $100. Ask for Toyota WS fluid--it takes a bit less than 4 quarts.

Ahh, and dealers often don't recognize the value in changing the fluid, since in the USA there is no recommended service interval for transmission fluid. A good rule of thumb seems to be to do an initial change at around 10,000 miles, then about every 30,000 after that. The early change removes assembly contaminants and sealant residue, and subsequent changes keep the viscosity and purity in good shape. BTW, Toyota of Canada recommends periodic fluid changes; go figure.

 

Which only proves how clueless Iffy Loob really is

I'd sooner never change the oil than let them touch it. The car will last longer!

Of course, you remove the fill plug first. Just in case it happens to be stuck, seized, etc, you won't find out after all the fluid is drained

 

Thanks for the replies! Correction: it was Tuffy that quoted $370. I would prefer to do everything myself, but I just rely on someone else's jacks and stands, which my apartment complex won't let me use. So the whole tranny case is one single piece, then? That's an odd design.

 

The transaxle has two major component pieces, since it is primarily composed of two motor generators. The two pieces are like two slices of bread standing up.

There is no need for a drain pan since there is no filter to be changed and according to Toyota, the transaxle ATF has no required change interval. However, as caring Prius owners, we like the idea of periodically replacing the fluid to get rid of the Si and Fe contaminants, and restore fluid viscosity.

 

Two pieces bolted together

http://priuschat.com/forums/gen-ii-...eshooting/44124-changing-transaxle-oil-8.html

and here is a cutaway

 

If you read this entire post, especially page 8 where I posted Hobbit's photo of underneath his Prius, you will discover there is a drain plug and a fill plug

Very much like a stick shift transmission

You need 4 quarts/litres max of WS fluid. Even at $10 a bottle, that's $40 plus tax

Not sure where they get $370 from

If they claim they need a "transmission fluid exchange machine" then they are completely full of s***

Maybe if they service the 5 speed auto in my FJ Cruiser they would need such a machine

 

We just purchased a 2008 Prius "Toyota Certified". Based on what I'm reading the transaxle fluid was likely not included in their maintenance. Would that be correct? If so, I'm definitely changing the fluid as my wife is using it on her mail route. After 13+ years of working on her vehicles one thing I've learned is keeping fluids changed is job #1.

 

Whenever you buy a used car you would do well to assume that no maintenance was done unless you have evidence to the contrary. Hence replacement of all drivetrain fluids would be a good idea so that your car has a fresh start.

 

Thanks all for the help. So I went to a do-it-yourself garage in Orlando and saved a whole bunch of money. It was very easy and quick. And I used just shy of 4 quarts. Very little dripped out after I poured in all 4. Also, I was able to snake a hose from the fill hole up through the engine bay and to the top of the car. This seems like a better solution because it provides for more gravity to drain the fluid. Unfortunately, I scraped the crap out of my car as I was backing out and nailed some low concrete that I couldn't see. Hopefully, someone can buff out the scrapez on the front bumper, but there are some chunks that need to be filled .

Anywho, when I picked up the fluid, the dealer questioned why I was doing it myself because the fluid had to be at some precise temperature. Is there any truth to this? Anything in the shop manual? The only thing I can think is that you get less fluid in when it's really hot.

Also, the dealer mentioned flushing the fluid. Can this really be done, and does it add any value like getting out any contaminants from the bottom of the pan?

Thanks again!

 

I assume that you were talking to the parts clerk. There is nothing in the Toyota repair manual about this. However, the parts clerk may have been acting in good faith as it is true that with a typical automatic transmission you have to get the transmission up to the correct operating temperature before you check the ATF level.

Regarding flushing the transaxle ATF, this is not required with Prius as there is only 4 quarts of fluid to deal with and the transaxle case does not have places where used fluid might hide.

The concept of an ATF flush is potentially useful with a normal automatic transmission that has a torque converter and hoses leading to the radiator, which trap old fluid. Hence, with a normal automatic transmission, a drain and refill might only get rid of 1/3 to 1/2 of the transmission fluid capacity.

 

Yeah, I understand how that helps as far as checking the appropriate level, but for draining and replacing?

 

The parts clerk is thinking of Toyota trucks which use the same fluid in there automatics and require Techstream software and precise temperatures to replace the fluid. Its a big job. Where the Prius is very easy dump & refill & go.
His comments have nothing to do with the Prius manual cvt.

 

My dealer changed it with no questions asked. However, I did not watch them do it so who knows if they did it or not. The only way to tell is to change it again and watch!!!!! ARGH!

Dealer service can be a real problem sometimes. A girl at work had here oil changed at the same dealer and they left the plug loose and it leaked all over her garage floor. She was the lucky one.

 

I'm just curious, but why does it require software and a precise temperature? It seems that even the most simple maintenance tasks are becoming impossible for marginally mechanically capable folks. :rant:

 

If you own an automatic transmission FJ Cruiser, or Tacoma, or Tundra, the answer is YES

The CVT in the Prius is very simple. Does not apply

Because that is how Toyota designed their automatic transmissions in the FJ Cruiser, Tacoma, Tundra, and as far as I know the rest of their lineup

The shop manual for my FJ warns that severe transmission damage may result if the Techstream tool isn't used to command the transmission to be at the appropriate temperature when checking the fluid or adding fluid

On my FJ pan, there are two plugs: a drain plug and an "overflow check plug." With the transmission at the right temperature, you're supposed to slowly add fluid until it just begins to dribble out the overflow tube

A huge, and royal, PITA

If one assumes they got the level correct at the factory, it would be a simple matter to drain the pan and precisely measure how much drained out. Add the same amount back in

But you're only getting out 1/4 of the fluid that way

 

I just wanted to contribute an update to this thread now that I've changed the ATF for the second time (at 114K miles). The first change was a few years ago (April 2008) at ~66K miles.
There were fewer and much finer shavings on the magnetic drain plug this time compared with the first time at 66K (see attached picture).
I also used a smaller diameter tube (1/4" OD) and tiny funnel, both of which worked pretty well (image attached). Next time I will use a slightly larger tube (maybe 3/8") so that filling will go a little faster. It took about 3 minutes filling time for each quart bottle. I snaked the tube down from the top of the engine bay and fed it into the fill plug hole (image attached). The transaxle took 3.8 quarts of ATF WS to fill it up to the brim.
I used ATF WS purchased from Marc Jacobson Toyota in Durham NC. It cost $8.50 / quart, which was quite a bit more expensive than it was in Charlotte NC a few years ago ($4.19 / quart).
I bought new aluminum washers and torqued the plugs back to 29 ft-lbs.
All is well!