After looking at a cut-away of a Prius transmission which was a real eye opener, and reading several posts on the subject I finally had my transmission fluid (ATF WS) drained and refilled at the dealer, he charged $90. I had 40,000 tough miles on the car and fluid looked it! It was very dark and compared to fresh fluid, obviously contaminated. Glad I did it!
Mine looked fairly clean when I had a drain and fill done at the 15k mark. I plan to do it again in a few thousand miles at the 30k mark, and make a video on how to do it. Replacing it every 30k is a good preventive maintenance approach, even if it errs on the side of overkill. If you cannot do it yourself, it is $120-$150 well spent.
I changed my ATF yesterday, at 29,000 miles, for piece of mind. My OEM fluid appeared an ashen red, suggesting metal in suspension. The job wasn't too bad. For refilling, I used clear plastic tubing and a small funnel. Total cost was $32 for the ATF, and a few bucks for the tubing, funnel, and a new drain-plug washer, plus two hours.
What's the process to do this job at home? I am assuming there is a drain plug, and a fill plug somewhere? What is the capacity of fluid? We have 30K on ours now, so I'd liked to change the fluid. I have done many tranny services in the past on other cars, so I am not expecting this to be a difficult service.
For those doing it yourself, make sure the car is level when filling. The manual states the ATF-WS needs to be 0-10mm from the fill hole. If you have the front of the car jacked up you will not be able to put in the correct amount. I noticed you can only get 3 quarts in with the front jacked up (you need 3.5 qts or as the manual said, 0-10mm from the fill hole) so make sure its level.
There is a pump in the Prius transmission Biult into the centre of the end plate it picks up oil trough a small strainer and pumps oil round the system.
Transmission fluid change is a fairly easy DIY, about on par with an oil change. You'll need: 1. 10mm hex socket, torque wrench, a few extensions, a breaker bar and a regular socket wrench. 2. Funnel and 3 foot (plus) of hose, to get the fluid down to the fill port. An assistant is almost necessity, someone to pour while you check for overflow, from below. Or you can use some sort of pump. 3. 4 liters or quarts of Toyota's ATF-WS fluid. (The spec'd. amount is 3.3 liters or 3.5 us quarts.) 4. 2 replacement washers for the fill and drain bolts. (not absolute necessity, but...) 4. The means to get the car safely raised and level. There are two bolts on the side of the transmission, top one fill, bottom drain. Both need 10mm socket. For sure break loose the fill bolt first, just in case you have troubles. When refilling, you can put in the first 3 quarts/liters quickly, then go slow on the 4th. Stop when it starts coming back out, and just let it trickle for a while. Put in a pinky and splash a bit out and it will likely stop dripping soon. That's basically where the level should be. After doing ours, I ran it for a day or two, and then checked the level again: it hadn't changed. (Just to help get your bearings in the first picture in the attachment: the large diameter circle adjacent to the bolt id'd as *1 (filler plug) is the drive shaft, coming out of the right side of the transaxle.) Addendum: Just want to clarify: the "hex socket" I mention in item #1 is maybe a poor description. In a nutshell, both the fill and drain bolts have a 10mm hex recess. The socket needed are like a hex wrench, built into a socket drive.
Great synopsis. I'd add that if you remove your right wheel, it's easier to see the two holes, especially when refilling, though this isn't required.
Does anyone know the refill vs. total capacity for Gen III? The 2012 Owner's Manual says the fluid capacity is 3.6 US qt, 3.4 L, or 3.0 Imp. qt. These are probably the refill amounts. Having both numbers helps in determing the percent of new fluid per change.
Procedure in post #35 of this thread. http://priuschat.com/forums/gen-iii...ng/72896-diy-transmission-fluid-change-4.html
I am having my transmission fluid changed this Friday, while they are doing an oil change and tire rotation. I figure I better after reading all the posts regarding the conditions of their transmission fluid when changed out early. We bought our 2010 in February with 35k miles and now it has 44k. Not sure what kind of miles the first 35K were, but I do know it was a rental, so I figure better be safe than sorry.
Thanks for the instructions. Would the below siphon pump from Home Depot work, you think? Plastic Siphon Pump-DH-10 at The Home Depot
ATF WS and two washers for the Drain and Fill plugs. You will buy 4 quarts., it will use 3.5. Toyota dealer parts department.
That's what I used. The siphon tube has to be cut shorter, otherwise it worked great. Much easier than the "long tube and funnel" approach for one person.
There are funnels available designed to be used with a hose extension. And then you've got a funnel dedicated to transaxle fluid changes, less chance of contamination. 6 in. Plastic Funnel with Handle | Princess Auto
