Transmission Fluid Change?

[MSHasan]

Hi all,

As some of you may be aware, Toyota don't recommend changing the eCVT fluid on the prius in their service intervals. However, PriusChat members on the other side of the pond suggest at least a single change at 30k and then 60-100k thereafter. My prius is at 97k and wanted to change the fluid to prevent against any future problems with the hybrid transaxle. I bought the ATF WS fluid from Toyota for £57 but upon trying to change the fluid I couldn't for the life of me get the drain plug off!

Called different Toyota dealers today (in London) to ask how much they would charge to it and got the same answer saying it's not recommended blah blah blah..

Is it really that bad to change the fluid? Apparently it can 'damage seals' resulting in leaks due to change in pressure?

This video is yet another example of why the fluid should be changed:

The difference in colour of the new and old is quite remarkable.

Anybody ever changed theirs on here?

Hasan

[MLW2233]

Very interesting video. For years with automatic transmissions I changed the oil at 15k miles and oil and filter at 30k miles. My last Mercedes at 148k miles had an auto gearbox that was silky smooth. Oil is very cheap. You can change most gearboxes for £15-20.

This Prius oil is expensive because only Toyota oil should be used. Interestingly in the USA Toyota oil can be bought for peanuts. Rip off Britain again. I will change my Gen 2 oil at 50k miles. Local independent can do it up on a ramp using oil supplied by me as I watch it being done.

[MSHasan]

Just an update, got it changed at my trusty local mechanic for only £20! Simple drain and refill so I suppose it's not difficult at all. Stood next to the guy and showed him what's where just to make sure he knew what had to be done. Car drives perfectly as usual!

[MLW2233]

How easy was it to get the new stuff in. Can the normal 1/2 litre squeezee bottle with the 9 inch tube/spout be used? How much was the fluid, and did much dirty stuff come out?

[pmf]

Thanks for the video. Intend to have mine replaced around my 80000 mile service, which is due in next couple of months.

Ive attached a link that I found for useful service info on the Prius and includes other fluids etc.

http://www.artsautomotive.com/publications/7-hybrid/116-prius-30k-service

[MSHasan]

The fluid cost £55 including VAT. £13 something per litre!

To get the new fluid in we used a small hose. The hose was threaded from ontop of the engine and guided into the fill hole and the new fluid poured in via a funnel. Once fluid starts seeping from the fill hole it means its full as that is also the level check hole.

Old fluid was black with a hint of red. The link from pmf suggests to use a sealed unit for filling as ATF WS is moisture sensitive - I didn't know that, hope my transaxle is okay

[kithmo]

The link from pmf suggests to use a sealed unit for filling as ATF WS is moisture sensitive - I didn't know that, hope my transaxle is okay

I would think that you only need to worry about that if you're not going to change it ever again.

[MLW2233]

The gearbox can't be airtight. When it was built and filled at the factory air must be present. In the USA lots of videos show it being filled just as any normal transaxle. In fact if you have ever been behind a large dumper truck with a straight axle, you can see the simplicity of it. One nut = drain, and one nut = refill. Beautifully simple, so why make it 'sealed for life' is a mystery. Keep it simple. Oil degrades. Take the old out, and put new in.

[gen2]

I want to do the transmission fluid change myself,where can I get the ATF WS,oil from.

thanks

[wass]

Looks like the only place to get the fluid from is Toyota.... I wonder why they stock it? It wouldn't surprise me the find the recipe for the tansmission fluid compound would turn out to be very similar to a better known and cheaper alternative (should it ever be analysed by an independent lab :))

[MSHasan]

Yes the only place to buy it seems to be Toyota main dealers. I searched online high and low but didn't find it for purchase, not even on eBay! Had to resort to phoning local Toyota dealer to ask for the price and make sure 4 bottles were in stock before I drove down to pick them up.

[kithmo]

but upon trying to change the fluid I couldn't for the life of me get the drain plug off!

Have you made sure you can get the refill plug off ?

It's not good draining the fluid only to find that you can't refill it.

I would leave well alone, although there are drain and refill plugs, the transaxle is designed as a sealed for life unit and opening any of the plugs increases the likely hood of introducing grit or swarf that may damage the box. The fluid does its job of lubricating the moving parts, regardless of what colour it is.

The transaxle is not like a conventional auto box that has lots of valves and filters that may block or not function well in dirty fluid, it is basically just a box of gears.

[MSHasan]

but upon trying to change the fluid I couldn't for the life of me get the drain plug off!

Have you made sure you can get the refill plug off ?

It's not good draining the fluid only to find that you can't refill it.

I would leave well alone, although there are drain and refill plugs, the transaxle is designed as a sealed for life unit and opening any of the plugs increases the likely hood of introducing grit or swarf that may damage the box. The fluid does its job of lubricating the moving parts, regardless of what colour it is.

The transaxle is not like a conventional auto box that has lots of valves and filters that may block or not function well in dirty fluid, it is basically just a box of gears.

I would rather spend the £60 odd and get the fluid changed than fork out thousands for a new transmission in the future. I call baloney on this whole 'lifetime' spiel! What do Toyota define as 'lifetime'? 100,000 miles? 8 years? 10 years?

I would hardly think they'd care what happens to cars after around 100k, they'd rather you purchased a brand new Toyota!

[Jellyb]

Changed my ATF at 150000 miles. After many discussions with local dealers about changing the fluid, all more or less refusing, I used a non franchise garage to do the job. As previously mentioned it is quite a simple straight forward job. The fluid removed still had a red tinge to it, but what I was most impressed with was the lack of metal fillings on the magnetic tip of the drain plug.

I would recommend anyone wanting to do this job to buy the genuine Toyota ATF for the Prius, the cost of this may seem expensive but is a bargain compared to replacing your gearbox.

I have covered another 51000 miles since I changed the ATF and had no problems.

[cass1]

I had the fluid changed by a Toyota dealer in Peterborough. This was after being told by certain members of staff, it was sealed for life, unnecessary etc. I complained to the management(new). The service manager contacted me and it was booked in for the change. I requested that I be given a sample of the used oil and was given a container with pretty much the whole lot in as far as I can figure out. My car a 2011 Prius had done about 26K. The oil was a very dark maroon colour. I am now happy as the car was pre owned and you never know the true conditions that the vehicle was operated in. It could be my imagination but I think the transmission noises are slightly less.The price I paid was less than the £99 they would apparently charge as I had a number of issues which have now been ironed out.

[PeteB]

My last Gen 1 had done 163,000 miles when I sold it, still with original transmission fluid.

I had discussed changing it with my dealer once or twice, but they thought it unnecessary.

However, the chap who bought the car does a lot of work on various Hybrids and changed the fluid himself. He reported back that it was very heavily discoloured (no sign of the original red colour left), but no significant metallic debris. On that basis I would probably have it done in future if my current Prius gets towards 100k.

However, he did also concur that my Gen 1 had no transmission whine at all, unlike some Gen 1 & 2 models that had passed 100K, so I guess the jury's out, but I'd rather be safe than sorry. A fluid change costing maybe £60-£100 once every 10 years or so isn't going to drastically affect the overall running cost, whereas a new power split device (aka transmission) probably would!

[Dinushka]

Prius 2 gen transmission fluid

[Dinushka]

I have a 2008 prius I need to change me ATF fluid my local dealer said once u do the oil change the car should be calibrated once the oil is changed is that true ? And is it a must?

[LeeroyJones87]

Hi,

Im posting this here too. PLEASE READ!

Big WARNING here! Do not attempt to change prius/ hybrid aft fluid.

As it says, it is sealed for life and that's what they mean. It very dangerous to attempt to do anything such as this on a PRIUS/HYBRID.

As a tech, i have seen a 240K prius mk1 for regular service and it has never had a replacement gearbox oil change.

Please note as a warning to everyone with a hybrid/prius, don't try this!

Hope this helps

[Devon Aygo]

Hi,

Im posting this here too. PLEASE READ!

Big WARNING here! Do not attempt to change prius/ hybrid aft fluid.

As it says, it is sealed for life and that's what they mean. It very dangerous to attempt to do anything such as this on a PRIUS/HYBRID.

As a tech, i have seen a 240K prius mk1 for regular service and it has never had a replacement gearbox oil change.

Please note as a warning to everyone with a hybrid/prius, don't try this!

Hope this helps

Think you need to qualify your statement that this is dangerous, the technical instructions published on Techdoc 1 and GT3 includes nothing unusual/dangerous in replacing the transmission oil.

[LeeroyJones87]

Hi,

Pasting this from another topic ...

Anybody who is not a qualified technician shouldn't be touching any of the hybrid system, including the CVT box. Its not like a AT box as it works and is designed totally differently.

As i said before there is no need to change the CVT fluid in any hybrid Toyota vehicle.

And again in the 8 years of working on Toyotas Hybrids, i have never HAD to change the CVT oil on this type of car.

It is best left as is in my opinion.

[Devon Aygo]

Hi,

Pasting this from another topic ...

Anybody who is not a qualified technician shouldn't be touching any of the hybrid system, including the CVT box. Its not like a AT box as it works and is designed totally differently.

As i said before there is no need to change the CVT fluid in any hybrid Toyota vehicle.

And again in the 8 years of working on Toyotas Hybrids, i have never HAD to change the CVT oil on this type of car.

It is best left as is in my opinion.

Replacing the fluid on a Hybrid E-cvt transmission is in no way different to the procedures employed on any other Toyota auto gearbox ( cvt excluded, some have special repacement requirements ) the Toyota hybrid drive does not use a conventional CVT gearbox hence the E-cvt name used by Toyota.

Obviously if you don't know what your doing damage / injuries can occur, if you are in any way unsure consult a suitably trained specialist,

The replacing of the fluid is not only the reserve of a specialist though and so long as the job is done in accordance with Toyota's instructions ( see: www.toyota-tech.eu for payable technical access ) no harm can be done it is down to personal preference as to weather or not you want to change your transmission oil.

The replacement of fluid is quite popular amongst high mileage Taxi users and I have seen some, not all cars having oil drained that was certainly in need of replacement.

[telmo]

Having changed my '10 Prius ATF at 20k, 18 months service, showed a decrease in viscosity:

New (from the right bottle)

40ºC - 24,6 cSt

100ºC - 5,5 cSt

Viscosity at 30 000 km

40ºC - 22,36 cSt

100ºC - 4,99 cSt

A little under 10%, not bad. I have read 15% is a good "change now" limit, so maybe 45-60k miles interval is enough for rheological properties to be reset.

The problem was...I suspected of some debris from the run-in period...as any gearbox, the first oil gets all the particulates from that...

But unfortunately haven't tested that in this sample.

From my point of view there is no risk in putting fresh ATF, except for a bad job (wrong level or a dripping plug).

[Grumpy Cabbie]

You sure that's the correct fluid for a Prius transmission?

[telmo]

Quite sure. Toyota ATF WS, sold at the dealer by then, their job to provide the correct one.