PIP transmission oil change @ 10K miles

i think there's some confusion in terminology here.

unless i am mistaken, you replaced the engine oil, no?

the prius has no transmission, so i'm not even sure what "transmission oil" would mean here.

by the way, your pip comes with complementary factory-recommended maintenance for the first two years, including free oil changes at 10k and 20k miles or 12/24 months, whichever comes first.

welcome to PC!

 

wow, that is very strange indeed. i wonder if the car sat on the lot for a long time before being sold? that difference in light transmission and color makes me really wonder.

 

Technically, it has a Transaxle, which just means the differential is in the same case as the trasnmission. It uses Toyota ATF WS. (Mechanically, it is a one speed transmission that never shifts, but with the two Motor/Generators and lots of software it emulates a CVT)

Conventional wisdom states that the ATF WS should be changed at 30,000 miles then every 60,000 miles.

 

Oh come on, take a guess, LOL

 

You're using 2 jackstands in the front, but only a jack at the back. That's better than no jackstands, by a long shot, especially since you're under the car near the front, still: I'd put 2 more jackstands at the rear side jacking points, on the rocker panel.

For the front jackstand locations, I prefer to put them at the forward end of the underbody rails, instead of the front rocker panel side jacking points. The latter seem to flimsy, with the extra weight of the front end.

Regarding your method of measuring what came out, then pouring in the same amount: I'd say it's much simpler, and more reliable, to just pour 'till it starts coming back out. Slow down when you're reaching the spec'd. refill volume, obviously. Stop as soon as you can once it starts overflowing, then just wait till it subsides. You can hurry that up by splashing it out a bit with a finger.

 

I would be surprised if there was no color change after 10,000 miles!

 

The aluminum gasket is deformed because it's supposed to deform to seal. If you torqued the drain plug properly, your new gasket is deformed now too.

I think performing maintenance at 10% of the recommended interval is silly and wasteful. Darkness of the oil doesn't mean that the fluid is spent. Send the drain oil out for some sort of analysis and you can start making recommendations.

Compared to a conventional automatic transmission the fluid in a Prius transmission doesn't have a lot to do. There's no friction material involved, just the meshing of gears, rolling of bearings and transfer of heat.

I call this the Pat Goss effect. If you watch Motorweek, any maintenance he recommends has to be done twice as frequently or more than what the manufacturer recommends. I suspect he's motivated to sell the products that sponsor his show. I can't imagine changing my transmission fluid every 10,000 miles (even if it's easy to do).

 

I don't know if visible light transmission is the right indicator for transmission fluid life. Just because it is dark doesn't mean it is past its useful life. For example, the color difference of motor oil at 1000 miles usage versus new could be just as stark a difference. You'd need to send it in for a used oil analysis to confirm.

The Prius owners manual doesn't even have a transmission fluid change interval. Not that I can find anyway. It only has an inspection interval every 30k miles. Doing anything more than the owner's manual is just peace of mind.

FWIW, transmission fluid change interval on my 06 civic is 120k miles according to the manual.

 

thank you tplus, that's a great write up and pics. those look like two of my favorite microbrews!

 

Great write up. I love the pictures.

While color is not a great indicator of fluid quality, analysis has shown that by 30k there is breakdown and contamination. I am going to do mine at 20k and have a sample analyzed to help build our knowledge base.

 

We have an 06 Civic Hybrid, still in the family (actually sitting in our garage at the moment). Maintenance intervals are determined by the in-dash Maintenance Minder. It tells you maintenance is due, and gives codes which correspond to maintenance items in the Owners Manual.

There are no maintenance intervals (for anything) in the Owners Manual, at least in the Canadian book. Maybe different in the States?

I did an early transmission fluid change on that vehicle, which muddles things a bit, but the Maintenance Minder has also asked for transmission fluid twice. I'd hazard it was roughly 60000 kilometer intervals, say 45000 miles.


I did find a Honda pamphlet at our dealership with a guideline. It called for 48000 kilometer or 24 month interval, for the CVT. And for regular Civic with automatic, the interval (in the pamphlet) is 96,000 km or 36 months. I've attached a scan of the pamphlet in pdf format.

Personally, I like to do a transmission (or transaxle) fluid change at the end of the first year, then every two years thereafter. Might be overkill, but it doesn't cost a lot.

 

+1
It's the right thing to do. It's a good idea to change the oil in any gearbox early the first time. There are manufacturing contaminants and break-in wear materials that are a good idea to get rid of. I held off until 20k miles for my first change because I don't plan to keep my Prius over 150k miles.

 

Really I do not like the lubricant color change, and it's very noticeable. Could it be because of temperature?
This should be answer by a real advanced Prius mechanic/engineer from Toyota support.

 

As a caution against apples to oranges, the Prius does not have a variable gear ratio CVT, it has a planetary gearset with multiple power inputs emulating a CVT.
Continuously variable transmission - Wikipedia, the free encyclopedia

 

Here we go again...
Ignoring the color change what about the visible pearlescence ?
The OP said: "Another interesting thing, the oil has a fine metallic sheen to it".


What do you guys think that stuff is ?

Threads on this subject always have posts from guys saying to follow the owner's manual, which doesn't have ATF changes scheduled.
Toyota knows best? I don't think so....

It's a just a gearbox. It needs a clean lube if it is to last a long time.

What about threads that include actual oil analyses from multiple cars showing the crud that comes out of these gearboxes?
Like this thread: ATF fluid changes ARE Required. | PriusChat

I added a super magnet to my drain plug, hopefully to catch some of the ferrous metal crud.

 

They don't? They built the car.

Prove it. I'm not a mechanic. I'm a computer nerd. I don't know anything about cars. Should I believe Bill Norton or the engineers that made my car? I'm not disputing what you are saying. But all that thread says is that there's a lot of crud in the oil.

I look at it this way. 10 years ago, I recommended defragmenting your computer hard drive on a regular basis. Your computer can develop a lot of leftover files from deleted programs or updates (crud) that will slow it down and possibly cause problems. Today? Nope. Oh, crud still develops in your hard drive. It's still there just the same. Left over files muck up things all the time. But it's no longer a problem because the new file system does not get hindered by random things as much. Also, today's faster processor just plows through the crud as if it weren't there. You don't even notice it going slower because your CPU is so fast. Only in a very severe case do you need to defragment.

Computers are not the same as cars, I know. I'm just using that as example of how things used to be and how things change. There's still a few computer guys out there that recommend defragmenting their hard drive and changing their oil every 3000 miles.

 

Go for it then.
Never-ever change the gearbox oil in your Prius.
And I'll run clean oil in mine.
Which is going to last the longest?
Why does Toyota recommend ATF changes for every other vehicle in their fleet?

I like to think I know a thing or two about gears and bearings.....

That's OK, you're not alone. If you search threads on this subject you always see posts from guys that say
"Toyota has a master plan for this gearbox. Trust and Obey".