Changing transmission fluid

There is no adverse effects to changing the fluid.

I’d swap it out especially if I had access to a lift, which will make the process very easy.

Enjoy your Easter weekend .

 

Do it, or DIY.

At a minimum, use the Toyota WS ATF.

 

Some info in this, though no mention of change. Use only Toyota ATF WS, 29 ft/lb for both bolts, remove the fill bolt first. Replace the washers (check with dealership, they should have, two diff sizes?). Fill with the car level. Funnel with hose extension from above is easy method. When fluid starts coming back out level is correct. Should take 3.8 liters (4 US qts) At least one of the bolts is socket head cap screw with 10mm socket?

 

"remove the fill bolt first" is a very good advise. If one removes the drain bolt first and then isn't able to remove the fill bolt, there will be a problem.
The washers are the same (# 90430-18008). I've bought mine two weeks ago, because I planned to change the ATF too, but I just didn't found any time since then.
You'll need a 10 mm Allen key and a 24 mm nut. The torque for both bolts is 39 Nm. (Feel free to convert in non-metric units. )
Take care not to open the inverter coolant drain bolt next to the ATF drain bolt!
Look here the pic in the second green rectangle, the sixth pic after that and the eighth pic after the sixth:
Getriebeölwechsel – Prius Wiki

SM-G950F ?

 

There are transmissions that might potentially have an issue changing the ATF, it is just not ever an issue in the Prius.

There are transmissions with internal clutches, going from a thick gooey old fluid to a thin new fluid, might be bad if it has internal clutches. The Prius only has one gear and no internal clutch, so it is not an issue.

There are transmissions with hydraulic logic deciding what gear you should be in, draining that may lodge some debris in a passage and alter how the trans mission shifts. The Prius does not shift, and has no Hydraulic logic.

ATF density can alter how the Torque Converter works, allowing more or less slipping from a stop. The Prius has no Torque Converter.

A really obnoxious mechanic pointing out hazards a Prius just doesn't have:

A mildly obnoxious person pointing out hazards a Prius just doesn't have:

(he calls the hydraulic logic a valve body, but shows all the little passages)

 

10mm Allen key socket? Not sure how to name it, but basically one of these:



As opposed to:



An extra-length ratchet is good too, for breaking them loose.

 

That's exactly, what I meant.
Sorry for my English, as I'm German.
I would prefer the first one too.
The other one (at least with a pipe) should do too. But this could end bloody.

And for the second bolt a normal 24 mm nut will be needed.

SM-G950F ?

 

I wasn't sure what to call it either, resort to pictures.

Honda's also have "socket head cap screw" for transmission drain/fill bolts, but with a 3/8" (or 10 mm?) square hole. Many years ago, planning to do a transmission fluid change I phoned up the service department, asked if they had a special tool for that. The service writer dutifully asked a mechanic, came back and told me how they just use one of these:

 

If Honda uses a 10 mm square or 3/8" (=9.525 mm), then a 3/8"-ratchet without a nut will fit.

But the Prius has a bolt with a 10 mm inner hexagon and one with a 24 mm outer hexagon shape. So one has to use the proper nuts with the ratchet.

SM-G950F ?

 

Tell your mechanic it is just a simple planetary gearbox, he should know what that is.

 

New guy here gonna change the ATF in my daughter's 2007. Is this the right stuff and am I getting it at the right price?

 

Yes it's the right stuff. Price a little high. Check with dealership parts dept too: they should have replacement washers too.

 

Thanks for the reply. I did a whole lot of reading and decided to go with Maxlife ATF that meets the Toyota WS spec.

Here's the funny thing. Once the fluid started to drip as I drained the old stuff, I jacked up the rear end as high as I could with a floor jack. It started to run a small stream for a couple minutes and then got back to dripping. I let it do that til it nearly stopped. I put it back down on the ground and when I filled it up it took about 4 1/4 qts. This car's manual says capacity is 3.6 qts. All I could figure is that jacking up the rear unleashed another half quart or so. Anyone else ever tried this?

 

Close. The second gen owners manual says 3.6 liters, or 3.8 US quarts.

The 2nd gen repair manual says 4.0 US quarts is "capacity", though that might be filling a brand-new, dry transaxle. 2nd gen manual doesn't "acknowledge the concept" of changing the fluid; 3rd gen is better in that regard, but still doesn't include it in the maintenance schedule.

Bottom line, the correct level is achieved by adding fluid while the car is level (typically raised as well, for access). When fluid starts coming back out of the fill hole, you've added enough.

There are lots here using alternative fluids, hopefully will work out for you. I'm a little incredulous though, when the manufacturers of these fluids say they "meet the spec" or words to that effect. As far as I know, these assurances are solely by the makers of those fluids, not by Toyota. Toyota's stance, in the Owner's Manual, is that any alternatives to Toyota ATF WS fluid "may" damage the transaxle.

Again, lots here are using alternates, and so far so good. But Toyota doesn't recommend any other fluid.

 

Toyota also recomments Toyota engine oil in their owners manual but we all know that's a joke.

Years ago Valvoline said right on their container that it is not to be used in Toyota WS CVT transmissions. They've since changed their tune. Valvoline has been in the lubricant bidness for a long, long time. I doubt that they threw that onto their packaging just for the hell of it.

 

I've not seen that. I believe they only spec a grade and weight. Page number?

 

Next time I'm in her car I promise I'll take a picture if I can find it. I spent yesterday chainging the downstream sensor and rotating the tires and looking up ATF change and a whole list of preventative maintenance things she needs. I'm sick of that SOB already LOL.

 

I hear you.