Prius C Tranmission/Transaxle/HSD Oil Change

No offense intended.

 

There are TWO plugs. 1) FILL Plug. 2) DRAIN Plug.

Since you don't get your hands dirty, you will have to take our word that your "mechanic," removed the FILL Plug, and as you stated: inserted a finger to assess the color of the ATF-WS fluid. Now if he had removed the DRAIN Plug, rest assured a good amount of fluid would have come out.

To help you visualize what we are talking about, look at wall clock that has numbers 1-12. 6 o'clock would be the location of the DRAIN Plug. 3 or 9 o'clock would be the location of the FILL Plug. Perhaps now you will see why it is impossible to NOT loose ATF-WS fluid by removing the DRAIN Plug.

 

Firsty, thanks to everyone, I wouldn't have had the interest or courage to try this without your suggestions and tips. But things did not go as smoothly for me today.

I only drained about 2.75qts, and was able to put about the same amount back in. I emptied 3 bottles into the new when the fluid came back out of the fill hole and I was able to refill those bottles to their original level with what was in the drain pan (old fluid + spillover new fluid). I assume that there is slighly less fluid than I started with in the transmission because there was fluid on rags and that I wiped from the drain pan. I'm not sure what might have caused this other than the fact that the front was raised about 8 inches compared to only 3 in the rear. I didn't think that the front being 5 inches taller than the rear would have such a great effect on the fluid level. Also the old fluid had a slow drip (once every 3 seconds?) when I replaced the drain plug.

Some questions I have are:
1) Does the car have adequate fluid to drive safely?
2) Why did so little fluid drain out?

Any recommendations are welcome too, I'm just trying to figure out what happened and if/what I need to do about it.

 

^That didn't sound like fun. I think you answered your second question already. Your vehicle wasn't oriented in the horizontal plane properly (evenly) such that the majority of the old fluid would drain out.

Good suggestion. I'm all spent now, so it will have to wait but I can rest assured knowing I can do this at any time.

 

I think the main thing is to get the fluid changed. While a magnetic drain plug's surely advantageous, and it's too bad Toyota's not providing one, I woundnt lose sleep over it.

Raidin, when mechanic checks fluid he's opening TOP (fill) bolt, not drain bolt. Personally I'd never bother with check, just periodic drain and refill, and eyeball transaxle for leaks at engine oil changes.

Regarding levels and quantites, maybe raise the car again, and this time get it LEVEL. Then check if you can feel fluid near fill bolt, top up as needed.

I'm guessing you got most, if not all, of the first fluid out, in spite of not being exactly level. At least all that CAN drain.

 

great information in this thread. i have to wait till the weather clears up to change out mine

 

Hi all,

I plan on doing my drain/fill soon although I had several questions:

- Is it necessary to change the bolt/washers ? If so..
- Does anyone have the OEM part numbers for the bolts/washers ?

Thanks !

 

You should change the washers. Assuming you're getting Toyota ATF-WS transaxle fluid at a Toyota parts department, you shouldn't have to tell them washer part numbers, just "transaxle drain/fill bolt washers" and the car model will do.

 

If I recall from our 2009 Prius trans, the washer was solid and thick aluminum. No need to change it at all...just torque it back down.

Is it different on the C?

 

It IS the same on a "c."

Unfortunately, Toyota eliminate d the magnet on the plug on ALL Gen III's that were present in ALL Gen II's.

Even the small ceramic magnet caught a lot of steel and iron worn off the gears and other parts.

I'm just NOT allowed to sell the kit through PriusChat.

Given the very long change intervals, a magnet is a good idea.

When I changed my transaxle fluid, I added an ultra strong N50 neodymium magnetic drain plug that a fitted to a machine milled out OE plug that I got from my Toyota dealer.

I didn't like what was available anywhere, so I made my own.

Nice thing is that it is an OE plug. So, it uses the same 10mm hex key socket.

 

OP posted that he needed part no cause he was ordering online. I posted part number, and suggested he just buy local if possible.

Both posts are gone now.

 

Reposting that transaxle drain and fill bolt washer info, lost in yesterday's shake-up:

Part number: 90430-18008
Description: GASKET

Note, this is for the regular Prius, maybe the same.

Again, if there's a dealership nearby, it's real easy to just pick everything up there, and a generic description of the washer will do, it's up to them to chase down the proper washer.

As to reusing the washer, not changing it: sure, it'll likely be fine. But this is something you do maybe every 3 years? Saving $1 or two by reusing a washer??

 

The Prius"c" uses the SAME washer.

 

I bought magnetic drain plugs for engine and transmission for all my cars. During my research on one with an all aluminum engine, I ran across this page:

Why Run PSR-Magnetic Drain Plugs

It mentions some SAE research that shows 80% of engine wear is due to metallic particles smaller than 10 microns, a size that oil filters don't readily catch (or at all?). I don't know if the same is true for transmissions, but seems like another good reason to consider these plugs.

 

That's interesting, considering that some people like to claim 80% of engine wear is due to cold starts.

 

I'm sure if you cold start your car and then drive it hard you'll add additional wear and tear due to the oil not circulating easily. It's also possible that cold starting and running of a car exacerbates the metal particle wear on the engine due to a less viscous oil being circulated.

Still, great to know that the magnetic plugs can really help. Now I'm just looking forward to the plugs arriving so I can replace the transmission fluid on both my Prius C and Lexus CT and see what's up with the fluids. Should be interesting. I may take a video/pictures of both of those jobs.

 

I'm at 150,000 miles and didn't know about the ATF change (I thought it was a sealed transmission and obviously I'm new to Priuschat) I've heard it can be worse to change fluid on high mileage transmissions. So do I change it or leave it alone?

 

150k is high mileage?

 

I can't see any reason not to change fluid, especially not because it's old. Hands down the best you can do is to change it MUCH sooner, but no time like the present.

 

I just changed my ATF this weekend, thanks for all the info guys!