DIY Transmission Fluid Change?

OK, so after months of thinking about doing this, I finally did it on Wednesday, at 15,000 miles.

For the most part, it was straightforward, with a few "wrinkles" that maybe I just wasn't clever enough to figure out:

1) Getting the wrench to the plugs required a pretty long extension for the fill plug. No biggie overall.

2) When I removed the drain plug, I'd assumed the oil would drain through the hole below it, but it somehow fanned out, and there was oil everywhere - which was really annoying. Maybe I did something wrong - but a word of caution to anyone considering this.

3) fishing the tubing to the fill plug behind the inverters was a pain, and made all the more frustrating after receiving my transaxle-oil shower...

 

Glad you were successful anyway. Maybe holding the pan up under the drain plug when we take out the last few threads might help. I guess I got lucky with the tube, I just stuck it down about where it looked like it should go and when I crawled back under there it was.

I intend to do a second change on mine at either 40K or 50K, haven't decided which yet.

Did you send an oil sample in?

 

Tumbleweed rightly said always take the fill plug out first. The reason for doing that is because if you drain your transmission, then find out you can't get the fill plug out you will be up a creek without a paddle.

However, if once you get the fill plug out, you put it back in finger tight, the transmission will drain a lot slower and reduce the used oil shower effect.

 

Is there a good reason to change this early? I'm used to changing fluids every 30,000 miles in conventional cars with dino ATF. WS is synthetic and probably doesn't work that hard in prius.

 

Take a look at this thread Jacek, I think there may be reason to change early. We have several UOAs that seem to back that up. http://priuschat.com/forums/gen-iii...vw30-transmission-oil-analysis.html#linkbacks

 

Thanks for the link. Based on the info, I will probably do ATF change at 20-30,000 miles. I had a few cars in which I kept 30,000 miles synthetic ATF intervals but that was due to towing. I guess Prius transaxle works hard too. I learned something new today.

 

Re: Sample - No, I didn't get a chance to collect or send in a sample - I was so surprised about the oil showering everywhere, and making a mess all over the lining of the "hatch" door, that as quickly as I could, I squirmed my way out from underneath the car.

Re: Fill plug - YES! I bet that would have helped immensely. There is a hole just beneath the drain plug in the belly-pan that looks like it is meant to allow for draining the fluid. Although I didn't see what happened, my estimation is that once I removed the drain plug, the stream of oil overshot the hole, and dispersed EVERYWHERE else. Re-inserting the fill plug to eliminate the venting effect probably would have solved my problem. Thanks so much! - Now, I'm ready for next time.

 

Leaving the fill plug in finger-tight is a great tip. Thanks!

 

I had mine first done by my mechanic at 5400 miles, just to get the break-in contaminants out. I'll likewise probably wait another 30,000 miles to get the next done.

 

I understand that OEM WS fluid is the way to go under warranty.

However, there appears to be consensus on BITOG that any Dexron VI oil can be used instead of WS and is superior while cheaper. Anyone here ventured or plans to outside the WS box?

 

Yes Bob Wilson did with his Gen1 and it didn't work out well. Sorry I don't remember the exact reason or what fluid he tried. Unfortunately he is no longer around to answer such questions for us.

I think that as far as the gears are concerned you could use another brand without fear. But don't forget there are some fairly high voltage electrical components in there. Insulation properties of the transmission fluid is probably not important in other applications and may not even be tested by fluid manufacturers. Toyota ATF-WS is not that much more expensive anyway, $7.78 per quart when I bought mine last summer.

 

He used Amsoil ATF. There was no Dexron VI back then.

BTW, what happened to him? I hope nothing bad?

 

As far as I know Bob is fine, here is a thread that explains the problem: http://priuschat.com/forums/freds-house-pancakes/87564-censorship-bob-wilson-prius-chat.html

 

Thanks for posting the link. I was not aware of this. This sucks big time. BTW, found good info on alternative ATF on gen 2 forums.

 

Here's some picture to go with Tom's write up. :welcome:

 

Good pictures 2ZR JDM, thanks. I just did my second transaxle fluid change two days ago. My first change was at 20K miles, I let it go until 50K this time (30K on fluid). I will post the UOA when it comes back.

 

Nice pics, thanks. I'm at around 26k miles on mine right now and probably will do this next year when I do my annual oil change.

 

Nice pix!

The hardest part of the job is probably buying the fluid. When I went to the dealer' parts department, they incredulously questioned my desire to replace WS fluid before 100,000 miles. :lalala:

 

Last weekend I picked up 4 liters of ATF-WS ($9~ per) and the 2 aluminum plug washers ($2~ per, robbery).

Still, all-in it was maybe $41. And: no hassles, no questions. I checked with the Parts Manager via email in advance, to make sure they had the stuff, and she was on a similar wavelength, ie: "what's with this ultra-long, or never, service interval".

So in a nutshell, it depends on the outfit: some toe the official line, some are more down-to-earth.

 

Here are my two transaxle oil change reports. One at 20K miles the other at 50K miles.

The excess silicone in the first sample was, I believe, left over from the casting process. It is not present in the second sample.

The excess aluminum in the second sample is questionable, where did it come from? is it really there? It's obvious from the writeup that the technician did not realize that this was my second sample even though he had my customer number and could have looked. It is also obvious he doesn't know an HSD transaxle doesn't have a torque converter. I have emailed Blackstone Labs and ask for an explanation which I will post. I also ask them what they are comparing our Prius transaxles to, if they are comparing them to other Toyota automatic transmissions the Universal Averages column would be of no value.

EDIT: Please ignore the error message you will get when you open the second file. Operator error on my part.