How to Change Your Transmission Fluid

I haven't tried @Mendel Leisk's paint can opener, but I like the idea. Need to try to remember that next time. I seem to have good enough success with just a small flat screwdriver and a modicum of patience. But I always appreciate a better idea.

 

It's basically a screw driver with a bent tip, which is advantagous, like a mini pry bar.

Rolls Royce I think would be something akin to battery clamp puller, that grabs both sides. But that makes it harder to lever, and it would be tricky to design an optimum jaw angle/size.

 

I changed the ATF & coolant today, thanks for all the good information on this site it was a big help. Once I had the transmission drained I poked around inside with a little inspection camera. I didn't really know what I was looking for but everything looked good to me, all the teeth were still there and in uniform.


Once I replaced the fluid I wanted to make sure it was full so I stuck the camera in again to look at the fluid level, my hands had some ATF on them so my daughter took this picture for me.


The 2011 Prius has 121,834 miles on it and I have had it for almost 12 months, it had 78k when I bought it so I just assumed the ATF and Coolant was the original fill. The old ATF came out almost black.

 

I changed mine at 120,000 miles. It was extremely dark. I changed it again at 170,000,
it wasn't quite at dark, but still dark.
Unlike brake fluid., I don't believe the color is a good indicator of when it should be changed.
It's cheaper to spend a little money and time to change it regularly then to replace the transmission!
It certainly won't hurt it.

 

Forced a dealer to change my ‘lifetime’ fluid at 47,000 when I bought my Prius pre-owner, I gladly paid for the service. I asked him to capture some in a clear water bottle. He was shocked as I was when it came out black.

 

I use a funnel with a 3 foot hose extension (roughly 15 mm OD), car raised and leveled on safety stands, and the engine under panel removed. I'm not sure if it could be done with the panel in place, it might be awkward to reach, and the draining fluid might hit it too. I've removed the panel maybe 24 times? for every (6 month) oil change, and for various other reasons.

You get very used to it and it goes quick. OTOH, if you've never removed it, the fasteners are likely going to be problematic. Maybe have a few spares on hand. These are the part numbers, and quantities, if you were to replace them all:

(11) - 90467-07201 (regular)
(2) - 90467-09227 (bigger, grey headed caps, 2 loc's at the rear)

Wash them out in hot/soapy water and work the mechanism of each, before reinstalling.

Have a extra long-handled ratchet wrench makes removal of the transaxle fill and drain bolt a lot easier.

 

At the meetups we use a pump and do the filling from above.

We’ve got it down.

Also thinking The Weekend of December 14th might work too.

 

I purchased 5 quarts of ATF before I started the job, I didn't want to have to go back in the middle of the job if I accidentally spilled one or something. So today I went back and returned a quart while I was picking up some of the fasteners and the part # they sold me are different from what you listed above. The (regular) ones I got looked identical to the ones I removed. The bigger one looked different but worked. Here are the part numbers and prices from my local dealership:

Now I have 2 spares in the glove box.

 

Could be they updated. I was able to get the other part numbers, from Japan. They're around $1.50 (CDN) apiece, plus about $10 for shipping pouch. I really have to start consolidating purchases though.

I'm not sure which numbers are kosher; I got those from an under cover TSB.

I'll try to check tomorrow, curious now.

 

@Bbonez yeah I think your part numbers are correct:


SUSPENSION CROSSMEMBER & UNDER COVER. 2011 Toyota Prius Hatchback HYBRID | Toyota


Hopefully my (ordered) part numbers work too. Maybe same, but superseded numbers??

 

I’ve done it with a pump and also with a funnel/hose. I think the pump approach is better, because with the long funnel/tube, once the tranny is full, you’ve got a lot of oil in the doggone tube, and it’s going to go somewhere.

 

Just go real slow with the 4th bottle, 100 cc at a time. Keep the spill pan under. And scream stopstopstop when it happens.

You should discard the excess anyway. I've got a Toyota publication somewhere, says to only use freshly opened bottles. Kinda like brake fluid. Might be overkill, who knows.

Found it (attached). Excerpt (that first line I don't agree with...):

 

Wow! You typed that up real good!

Considering they say you NEVER need to change it, there would be no real reason to save something
you wouldn't ever be using, so why keep it?
But, since MOST people change it at 50,000 after doing it once, that 1/4 quart isn't going to be a problem.
Unless it's 2 year between changes.....
I used the last bit in the quart jug, everything is fine.
Toyota says "ATS-WS "MAY" absorb moisture...". That doesn't mean it WILL. It MAY.
When you open the transmission, air gets inside, what keeps it from absorbing moisture their?

Brake fluid will, and does absorb moisture.... so use it up, or throw it away if it won't be used soon.

I think it was 3 3/4 of a quart to fill it right? So you fill it with 3 3/4 of a quart, then get under there and pull
the hose out. It will probably seep out. If you have to add more only add what's needed. Let it drain out
of the tube so when you pull it out there will only be a little in there and not make a mess.

But it's a small amount, so throwing it away if you don't plan on using it for a year or two is not a biggie.

You could always vacuum seal it, and then you could use it.

 

They're concerned, who knows how important though.

Like you say, a little bit left over, and a few years till the next change (if ever), no biggie.

 

My thinking is this, Once you torque down the drain and fill plugs the CVT is sealed and the air inside is probably less than a cubic foot so even if the ATF absorbs all of the moisture in that small amount of air it would be negligible. If the ATF is sitting on a shelf in the garage with new air constantly circulating through the amount of moisture is potentially much higher. Even if I could save a quarter of a quart it would take me 4 drain and fills before I could save $10.

 

The trans would have a lot more air than the 3/4 empty bottle, that you would squeeze the air
out of. It's sealed, So it doesn't matter how much air is OUTSIDE of the bottle, it can't get inside of it.
Unless you leave the cap off...
The remaining portion wouldn't be subjected to the heat and stress that the transmission would be.

Save it, or throw it away. It really doesn't matter.

 

I did use left-over fluid, a cup or two, every time I've done it. Only noticed that Toyota edict in the last year or two. I'm not losing any sleep over it, but if I ever do another change guess I'd abide by it.