DIY Transmission Fluid Change?

I have had D6 in my car since it was born 120,000 miles later its running perfect.Best GL4 on the market imho.

 

Best for the manufacturer and their dealer network? Or best for the car?
There can be a higher tech ATF than Toyota's ordinary 'World Service'.

 

Toyota's not completely chauvinistic about all their fluids, just the transaxle. With the latter though, they're VERY emphatic, that any other fluid could damage it. To say you know better is fine, if you intend to keep the car forever, but to intentionally use a non-recommended fluid, with a strong caution against doing that, and then trade or sell the car down-the-road, is unconscionable.

 

Possible, though being a dealer in Marin County California I'm not surprised if that is what they charge. I was willing to pay up to $150.00 for the convenience of not doing it myself.

I fully understand and I can't say you're empirically wrong, you go with what feels right and Toyota WS isn't a bad fluid by any means. Mine had almost 55k miles and still looked and smelled decent.

Personally(not to be used as fact), everything I've read/watched leads me to believe that Toyota WS is just a light weight trans fluid to meet the standards' of today's vehicles in improving fuel consumption by lowering the parasitic/mechanical drain on moving parts. Redline D6 is Redline's (synthetic, which I prefer) version of that. Multiple companies have their own versions of this same weight trans fluid. eg Mercedes Benz has their fluid, "Nag2" if I recall correctly, which is ridiculously overpriced at something like $22.00 a liter because MBZ put their name and logo on it; much cheaper (and superior) alternatives can be found.

I'm 100% certain there's nothing special in the Prius Gen III gearbox that absolutely requires Toyota WS and/or there being something special in Toyota WS. I'd also be comfortable using Valvoline Maxlife ATF as I can get it for under $25.00 USD on Amazon for a gallon (3.8 liters) and it's synthetic, but I'm a HUGE fan of Redline products, maybe next change I'll use the Maxlife, depends how frugal I'm feeling. If I had any doubt, I'd not do it, a Prius gearbox can't be cheap to replace and I intend to keep this car well over 100K miles.

 

You're welcome.

I overall agree and you're not going to go wrong using the recommended. But better alternatives can and are to be had. It's a case-to-case basis, imo.

 

Good to hear and I agree. I'm going to drain and refill my 2002 Highlander with Redline D4 (another great product imo) next scheduled oil change.

How often do you change the trans fluid on your Prius?

I'm probably leaving my D6 in for 55-60K. The Toyota WS fluid I drained nearly had 55K on it and was still decent and it wasn't synthetic. I'm also rather tame on the car, trying to maximize my mileage. Do wonder how some people drained theirs at around the same or lower mileage than mine and had a completely different experience. Being pitch black and smelling awful.

 

I completely agree that most ATFs are the same just branded differently and sold for higher prices and then the truly superior ones are found in an automotive garage shelf and not on the recommended list. HOWEVER, the Prius doesn't have a standard gearbox. It is one of a very small number of vehicles that puts multiple high voltage motors embedded into the transaxle which is where the ATF goes. There have been numerous reports of people using different ATF and then start finding copper shavings in it later or having an MG failure or HV isolation leak failure.

Any ATF that has a high enough dialectric strength will work. The problem is that nobody lists that on the bottle. Toyota's fluid they recommend wont break down in the high voltage environment and it is purpose built for that. The Prius is a special animal. Lots of other hybrids don't have the HSD system and therefore don't submerge the motor-generators in the ATF itself. As an ATF manufacturer it doesn't really make sense to develop and market something for a small percent of the 2% of vehicles that are hybrids on the roads.

 

There has never been any reports of a trans failure on this site because of using different trans fluid.
There has been hundreds of posts about people using other atf with good results. Lots of Redline users. Redline in my 07 since brand new that’s 11 years of use. No dielectric there.
Maxlife mentioned the most. I see this on Bitog also. Posters on Bitog rarely use factory fluid.

The copper shaving your quoting was bob Wilson’s years old post about using an amsoil product that was known to attack copper. He had high copper content in an uoa not shavings. That was it.

In a g2 the atf never touches the Motors. The mgs are in a sealed chamber surrounded by separate sealed inverter coolant cooling channels.
This was confirmed by mr Weber in his fabulous Weber automotive youtube g2/g3 teardown training videos.

The reason there is no dielectric mentioned on an atf bottle is there is no dielectric property in atf fluid.
Could never be. Dielectric fluid must remain pure and clean and not contaminated so not to be conductive. Atf quickly becomes contaminated with metal wear especially in a Prius where the fluid is
Only used as GL4 gear lubricant. Dark fluid= Metal wear= Conductive. Doesn’t need to be a dielectric anyway.

An WS is used widely in Toyota cars and trucks. Has been for years. It was not designed for electric motor use. It’s not even synthetic.
It is not designed to be used only in a Prius. It’s claim to fame is a low viscosity long life big calcium pack trans fluid.

 

Two large electric motors bathed in ATF does not strike you as unique in a transmission?

 

Are you sure redline D6 is suitable for the prius? On Amazon they say it does not fit .

Posted via the PriusChat mobile app.

 

For me Toyota's warning trumps all other considerations: sure the others may be ok. Or not. Why take the chance?

 

Not really what i said, but I do not believe that is the case either way? If the electric motors were "bathed" in ATF, they'd attract every tiny bit of ferrous metal that was worn off due to normal use and released into the fluid and that would be dangerous. Imagine having a metallic sludge magnetically attached to your electric motors.

As far as I know, the motors are sealed off and the only thing the ATF fluid touches are the shafts and planetary gears of the transmission.

I am really curious to know if I am wrong though and the motors are indeed "bathed" in the ATF? Anyone.

 

I went off the Redline's website and their vehicle/product compatibility chart. Edit: D6 is also listed as compatible for a 2007 Gen2 Prius.

 

And that's fair enough, as you're not going to go wrong using the Toyota WS, in my one experience, it's a very adequate fluid for the Prius.

Personally, I believe there are better alternatives if one does some research. Also of note, if we're trusting Toyota's word as the end-all-be-all to the Prius, we shouldn't be doing transmission fluid changes at all; as they also state "lifetime fluid" in regards to the Toyota WS in the Prius. While I'm certain there are Priuses (sp?) with 200k+ miles on the original WS fluid, I just can't wrap my head around a "lifetime" fluid.

 

Their fluid recommendation, I take to heart. Their lifetime claim, not so much.

 

At about 23:00 they tilt the case for M/G2 and you can see ATF in it.
At about 31:30 they get the winding for M/G1 out and you can see ATF in it.

In retrospect, sprinkled may have been a better term than bathed.

Other than watching two guys struggle, the Weber Auto series is better explained.

 

Thanks for the vid post, I do appreciate it. But I'm not really seeing what you're seeing. If the fluid was in there, it would be trapped and then dripping off the copper-coil-mesh when they pulled the parts out of the casing as its prefect place to trap fluids.

I'm still confident in my use of Redline D6, as I do not believe Toyota WS has any special properties needed by the Prius transmission to function or last and Redline list it as a suitable alternative.

Guess time will tell, not planning on changing it out again for 55-60K miles. If there is something harmful, I'll likely know in a few thousand miles or less. Will post if so.

edit: Just realized that vid was for the 2nd Gen. There's a 3rd Gen vid that pulled up as a recommend watch on youtube.

 

Thank you thank you are exactly right. The fluid is no where near the motors. Can you imagine the mess with oil on the stator?

 

D6 fluid will result in zero wear in our trans. I have the UOA to prove it in the trans sticky at the top of the forum.

WS has no magical property's. Its not even synthetic lol...its a dielectric fluid with dino oil lol...its magic!!

 

Your just seeing residual oil dripping down. My god why is it so important to you?

Go to the Weber Automotive Tutorials on youtube. GFO is showing there G3 video. On the G2 trans video on youtube I ask Mr Weber who knows more about the trans that you and me if the mg's see fluid interaction and he says they do not they are in separate chambers.

At first he says they do I disagree with him and he goes back and checks and comes back and says he was wrong they do not see interaction.

Awesome tutorials. Awesome instructor.