Transaxle Fluid Drain & Fill (DIY Easy as 1-2-3)

I finally got around to changing the fluid in my CVT. My 2010 Prius III had just under 70k miles. The old ATF still had a sweet smell to it and even had a dark red color when coming out. Getting the hose down through the engine for the new fluid was a PITA but I finally got it.
4 new bottles of fluid!


$28.48 for the fluid and gaskets.


I hooked up the funnel to make this easier.


Here is the fluid going into the fill hole.


You can see the fill hole with the tube in it and the drain hole below and to the right of the fill hole.


This was as the last of the 4th quart went in and it overflowed the fill hole.

 

good price on the fluid

 

Sorry but newbie here. Why are you guys changing the fluid so early at say 35 or 45K? Thanks.

 

Well, the elephant in the room is Toyota, saying never change it, so we're basically talking among ourselves. Anyway:

I've done a couple of changes, one at the one year mark (around 15,000 km) and one at the three year mark (around 40,000 km). The drained fluid at the one year mark was already quite dark. At the three year mark the fluid looked near-new.

My take from this is an early change is important. And, it's cheap and easy. Subsequently it's ok to stretch the interval.

 

I tried to change my transaxle fluid today but I could not break the fill plug loose. I was using a 10 mm hex with 3/8 drive but there just is not enough space to position the wrench, get a firm grip, and apply some torque. What tool/s did y'all use to loosen that plug?

(And by the way I'm glad that I tried to loosen the fill plug, before draining all the old fluid out! That was a suggestion from someone on this forum.)

 

I'm using an extra long handle (about 17"), 1/2" ratchet wrench with swivel head. I put a 3/8" adapter, and 3/8" extension (3" or 6", and then the 10mm hex male socket. Also, you want to raise (and level) the car a decent amount, give yourself more room. Taking the engine undercover off opens it up better too.

 

I use a 3/8" racket then put an extension rod on it to act like a "breaker" bar. Has worked 3 times now on 2 different Prii using this method.

I have tried a 1/2" breaker but could never get it situated right.

The location of the fill plug is precarious .

Always best to try the fill plug before the drain. Sounds like in your case it was sound advice.

 

I got that wrench when gearing up to do a coolant change on our son's Civic. I was worried about access to the engine block bolt 'round back of the engine. The windshield cowl had to be removed for access (similar to Prius, but at least the wipers can be left alone). I was looking for a long handle, 1/2" drive, and ratcheting. This one (Jet) just happened to also have the swivel head, and that turned out to be indispensable, wouldn't have fit otherwise.

It was about $70, and I picked up a 24 mm deep socket for maybe another $30. Completely retail, ugh. But once you have it...

 

Thanks to all ... It sounds like I just need to find a longer wrench. The swivel head looks like a good idea too.

I did have the front of the car up on the ramps (I was changing the oil too) and I jacked up the back onto stands, so it was fairly level. It's just annoying to have spent all that time jacking up the car and taking off the underpanel, and then have to quit without finishing the job.

 

How many miles on your Prius?

Better to have attempted and live to fight another day then damage the fill plug and not be able to ever do it.

I was attempting to change the front diff fluid in our 98 4Runner with 259 k miles on it a couple of months back and ended up rounding the ends and not being able to do it. But that was with the 1/2" breaker and me standing on the end, so it didn't happen with out giving it my best shot.

All the best.

 

How are those electric impact drivers for something like this? I've managed to dodge them so far.

A quality long-handled wrench makes bolt breaking a lot less "eventful". There's still some pushback, but the extra leverage is really helpful.

 

Thanks! I'm at 38,000 miles. I will reattempt the transaxle fluid at the next oil change, or maybe the next tire rotation. I'm hoping to do all my own maintenance on this car and never take it back to the dealer, at least until 100k mi, at which time the car will be ten years old.

 

You got me thinking: the wheel lug nuts are 76 foot pound torque, and as long as they're correctly torqued, it's never a big deal breaking them loose. It helps having a longer handled wrench, either the Toyota supplied one, a breaker style wrench of your own, or one of those cross-shaped lug nut wrenches. Maybe easier 'cause they're nuts, less turns of threads? Plus you put your weight on it.

With the transaxle, it's bolts with more thread turns, maybe more friction to break through. Plus you're on your back, can't put your weight on it, using a short wrench. Torque spec on those bolts is 29 ft/lb btw.

Yeah, longer wrench, make sure it's square-on, there'll be no problem.

 

This conversation got me thinking as well.

Santa left a gift card that I used this morning to get a better ratchet:


Handle had a quick connect type mechanism that allows it to extend up to 18". Compact when needed, but extendable when required.

Probably going to be my new go to ratchet .

Thanks for the insight.

 

I'm a firm believer in changing fluids. The "lifetime" might be great for those that don't keep cars long but I keep cars a while... so to me if it's a fluid it gets changed proactively.

Seems nice and simple. Very similar method on fillings with my RCF/Mercedes/NX... except for those cars you run the softare, get the car up to a specific temp for the transmission fluid then drain out the excess and close it up once it just barely drips. It can get nerve racking a little bit.

This however looks super easy in comparison! I'll be doing this on my CT in two weeks. It's got 69k miles on it from the previous owner, and though maintained at the dealer it's whole life I very much doubt they did the trans fluid...

Great price BTW. I called my local dealer just to see and they are charging almost $20 a qt for Toyota WS...smh.
It's a shame I have to go on ebay across the US to get it at a reasonable price that includes free shipping.

I'll take a picture of the fluid when it comes out to see what color it is.

-Nigel