Differential Fluid/Gear Oil

Hard to tell the video: they’ve gone to Torx style?

you’ve got the repair manual, can you post excerpt or screen grab?

addendum, here it is:

https://attachments.priuschat.com/attachment-files/2024/12/261284_Gen5_Prius_Prime_Transaxle_Fluid_Replacement_1.pdf

 

If the pictures don't look the same, then are you certain you're in the right spot? Take a pause and look at the whole thing with new eyes.

I will say I've brought oil and filters with me to oil changes and they just charge me for the labor. Can't imagine a trans fluid change would be any different for the vast majority of dealerships. Just make sure you note 'customer is providing own fluids' when you bring it in, then double check the bill before you pay.

 

A little easier on my pc:



That looks somewhat similar to this:



But with some differences. I would carefully compare the underside on yours to this pic. That one appears to be hex socket, likely 10 mm per gen 3 fill/drain bolts, which I'm familiar with..

If you opt to remove it, drain into a clean container, just incase it turns out to be coolant. Too, you could just loosen enough to get a drip, check if it's oily or coolant.

 

Also, the Repair Manual instruction (linked above) describes the fill/drain bolts as requiring "10mm hexagon socket".

The do take some oomph to break loose.

 

This might also be a filler plug. This one is the other side of the transmission. But this one is not 10mm either, its 24mm huge bolt.


The reason I am confused with the filler plug is because I watched several of toyota corolla or rav4 transmission fluid change videos and their filler bolt is either exactly in this area (above the pictures you can see that area)
OR
Other side of the transmission which you can reach from the wheel, I shared the video above.

None of this bolt is 10mm so I am confused.

 

That sounds sim to gen 2 Prius transaxle fluid drain/fill bolts; they were different for sure.

take your time. Again, you can always just loosen enough for a drip, see what it looks/feels/smells like.

gen 5 repair manual doesn’t have the line-art per gen 2/3, just screen grabs from the model, a step backwards imo.

 

Ok. First, when Toyota says a 10mm hexagon socket, they don't mean a bolt with a 10mm head. They mean a bolt that has a hexagon "hole" in the head that a hex socket goes into. Like a giant Allen screw. Like the one in the picture Mendel posted.

That being said, I think the bolt with the TE label is the one you want. Toyota probably planned on making it a 10mm hex like it's always been in the past, but they may have decided to print TE on the head to remind techs that these transaxles need the new TE fluid and not the old WS fluid. In order to have the space to print TE, they changed from a 10mm female hex head to a 24mm male hex head.

[I deleted a section here - wrong info I think}

The other problem with the instructions from the repair manual is that I don't think the illustrations are from the PB10 transaxle that you have. I suspect they are from the PA10 that's used with the 1.8L. The same manual covers the instructions for the PA10(HEV 1.8L), PB10(HEV 2.0L), and PB12(PHEV 2.0L). While they're very similar, they might not look exactly the same.


Honestly, you're probably better served taking it to a dealership at this point. Better that, than you removing a bolt you're not meant to(that Torx bolt was absolutely not one of the bolts you should be trying). By the time you need to do the next trans fluid change, there's sure to be a youtube video showing where the plugs are. Or you could ask the dealership to let you sneak a peek while the car's in the air. It's much easier to look over the whole thing when you're not laying and squirming on your back with the car six inches over your face.

 

Here are multiple photos of the PB10 transaxle all by itself:

JDM 2024 TOYOTA PRIUS HYBRID CVT TRANSMISSION ( PB10 )

 

O just yok both fill and drain. Tank is empty. Now, I am looking the used washer, and the 4 washer that I bough, is slightly different. See the image


The one on the left is used one. On the right one I bought them. The reason I bought 4 is, I actually bought 2 and 2 different washer, just in case I buy wrong one. But they seems exactly same, unless they give me wrong one.

The ones I bought is very slightly thinner as you can see.

 

Have you stacked the different new gaskets on top of each other to see if the inside and outside diameters are exactly the same? It might be a trick of the perspective, but the upper two look slightly smaller than the lower two.

 

^ Post a pic of the other side of this? Is it the lower bolt, the drain bolt? And removing it you got copious transaxle fluid out,? Just curious.

The large one has GOT to be the fill bolt. As @Hammersmith said, it's got "TE" embossed. And it's at the right location:

 

I am done, finished.

I measured them with very sensitive caliber. Old washer (Gasket) is 3.30mm thick, new ones are 2.90. I believe when you torque it to 37 ft, it will get smash. BUT do you have any idea whats the different between of those 2 washers? Because Toyota send me those but didnt label them, just put in the same bag. When I look very close and measure, I literally did not see any difference. So I just picked.

 

Yes that was the drain bolt. I got 3.1 lt of old oil. But I put 3.4 lt of new oil. I know its strange but, as soon as I took filler bolt, I looked inside with snake camera. I see that I had less oil than I was supposed to (See the image)

I had like the red mark. The car was as level as possible. When I filled it up, I kept it between 0 to 10 mm.

 

They're probably identical. I guess it's possible you were sent all 4 of the wrong ones(instead of 2+2), but that seems unlikely. Especially when the prices are identical between the two part numbers. You'd think there'd be at least a couple pennies difference if they were physically different.

If I was forced to guess, I'd wonder if the inventory software system Toyota uses has a limit to how many part supersessions can be stored in a particular file. Say there was a limit of 64, but there were actually 95 supersessions. One solution would be to have two different active part numbers for a particular part. Active part number 1 would take the first 64 supersession numbers, while active part number 2 would handle the remaining 31 plus any future numbers. The only reason my mind went this way was because I expanded one of the "About this product" lines and saw more "Previous Version(s)" than I've ever seen before. It made me think there might be a software limit. But that's probably not correct in the least.

 

I emailed the guy from Toyota dealership, and he replied me and said they are the same. So it should be fine.