Transmission fluid change

Just curious....why did you go with Mobil 3309 instead of OEM Toyota WS ATF?

 

What does the second gen Owners Manual spec for Transaxle Fluid? If it's Toyota ATF-WS, I'd be very reluctant to use anything else.

The Mobil fluid says:


According to Imperial Oil, Mobil ATF 3309 is of the following quality level:
Audi G-055-025-A2
Saturn GM9986195
Toyota Type T-IV
VW G-055-025-A2

 

The Mobil 3309 might be an issue with the Prius, it doesn't seem to be a compatible fluid to the Toyota WS fluid. Might be worth while to redo it with the correct fluid

 

Mobil 3309 is the wrong ATF to be using in the G2 Prius. The viscosity of that fluid is greater than Toyota ATF-WS which is the correct fluid.

Mobil ATF™ 3309 automatic transmission fluid | Mobil™ Motor Oils


Mobil 3309 would be OK if you had a Classic Prius since that uses Toyota ATF T-IV. However your profile indicates you own a 2008 which is G2.

 

i screwed up. eager to do transmission/transaxle change for my wife and didn't read carefully. had a case of mobil1 3309 sitting around that i use for the volvo knowing it's the same stuff as toyota atf-type iv. thought it was going to fine for similar vintage cars (2008) and would be the right one for the prius. ugh.

gonna re-drain and fill this weekend. hopefully no significant permanent damage done. asked her to warm it up gently when she drives it until i get around to getting some atf-ws and get the drain/fill done. at least i'll be familiar with the procedure this go around.

came here to read the how-to/procedure and should've paid more attention to the fluid type. but glad i posted and had you guys catch my error.

 

You don't have to worry about permanent damage, as Mobil 3309 will lubricate the transaxle's moving parts. Since it is thicker than ATF WS the efficiency of the transaxle will be slightly less than it otherwise could be.

 

It time for me to change my transmission fluid on my Prius. In the records it was first done at 53,000 miles (I bought this car 4 years old). I am change it at 60,000 mile intervals. I also plan on using Amsoil as I want my transmission to last as long as possible. After researching many different ATF's for the Prius I believe this is the best shot.

I have also read many posts on this site (too many) where it is argued that "you must stick with Toyota brand WS fluid."

First Toyota puts those warnings in their manual to make money and to play it safe with any possible lawsuits. If they have you convinced that you must use our "special" fluid, then they will have you keep coming to them to buy it from them and they make a bigger profit. As an aerospace engineer I have seen this all the time, I imagine Toyota is no different. A company will stock a common bolt but give it their own part number so that you don't know that you can buy that common bolt somewhere else. So customers even put in their specifications a statement to prevent this such as "you must use industry standard parts where possible and that they must keep their industry part number."

Second, The whole dielectric properties of the fluid that many seem to be concerned with, is totally false. My specialty in aerospace engineering is designed coils, windings and solenoids in fluid power applications. The copper magnet wire is coated in a polyimide coating (also known as Kapton) in accordance with NEMA 1000. The polyimide coating is hard and pretty much impervious to everything to include ATF. While winding it, it is "wet wound" with a varnish as additional protection. I have personally done experiments with dielectric testing of fluids. Our conclusions is that these types of fluids do not conduct electricity (the ATF's are all pretty much the same). As the fluid is used in a metallic case or running through metallic tubes, metallic particles (in the micron size range) flake off into the fluid. It is these metal particles that make the fluid conductive. This will happen no matter what fluid you use (Toyota WS or any other brand). So by this, the dielectric issue is a non issue.

I saw an earlier post in this thread about "Prius owner's being uptight" I have run into this as well on this sight. The attitude seems to be follow Toyota like lemmings and just do whatever Toyota says. I don't need to come to a message board to get that advice. I come here looking for something more. I guess I am not a typical Prius owner, my previous car was a Camaro. In the Camaro boards you could get a lot more inputs then "Just do what it says in the manual". There was a lot more ingenuity and experimentation. I guess that was what I was expecting when I came here.

Anyways, my neighbor HAD a Prius and never changed his transmission fluid as it is "lifetime" At 200,000 miles, his CVT went out and he had to get a new car. So much for Toyota's recommendations. With regular fluid changes you should be able to go much more than that.

I am not sure how true this is,it may not be, I'll admit, but I do find this intriguing that one of the motivations that Toyota has to make WS a lifetime fluid is environmental fees from, less frequent ATF changes (less hazardous waste).

SO I will be sticking to 60,000 mile fluid changes and using a reputable brand such as Amsoil to keep my CVT running well beyond 300K.

 

Love your post. Same thing I said 9 years ago. I am going on 9 years
And 99,500 miles on Reline D6 on my Prius. Trans runs perfect.

2 things:
One is if do use an after market fluid like Redline this is a pure poly base stock
Fluid with no life pack like calcium which is used as acid reducer which will
Reduce the tan. This life package is why Toyota can claim lifetime fluid. Unfortunately calcium is a wear agent. So using Redline you have excellent wear numbers but at around 30 or 40k
Miles you will notice the tan start to creep up. High performance fluid requires
High performance intervals.
I change my fluid every 35000 miles and now at 100k will go every 50k.
My last pull at 75k miles the fluid looked really good like brand new.

To all readers:
If u plan on keeping your brand new Prius for years your best remedial bet is to replace the Trans fluid at 5000 miles. That's where the most wear is the break in. Your then good to go for at least 100k miles.
My new Prius in 2007 at 5000 miles looked bad. Have not seen any wear
Since.
There's nothing wrong with WS. fluid. I just prefer to use certain products
That I know from experience are better.

 

Well it only took me 3 years of procrastinating, but I finally changed the transaxle fluid yesterday. Since my plan was to originally replace it at ~100K, I got 4 quarts of Super Tech Dexron-VI which says "Also suitable for Toyota WS applications". I only plan to leave it in for 1-2K miles, mostly as a flush. I will put in official Toyota WS fluid and replace the washers the next time I do this.


Considering that the mileage ended up being about 150K, I thought the fluid actually looked pretty good. Here is some on the corner of a clean paper towel:


I have no basis for comparison, but this is what my magnetic drain plug looked like:


Anyway, as long as you have the 10mm hex key and 24mm socket, this is an easy job. I think I had about 3 feet of tubing on my funnel, less would have been better. I rolled the front wheels up onto Rhino ramps to loosen both plugs, then rolled it back off the ramps to do the draining and refilling. It was all uneventful except for the fact that this fluid comes gushing out unlike any oil I've ever changed before. Quite a bit splashed onto the bottom of the car and on the ground around the pan, fortunately it's easier to clean up than spilled motor oil. I poured in all 4 quarts, some leaked back out into my drain pan. I tightened both plugs as well as I could with the car on the ground (not a lot of space), then I rolled it back up onto the ramps to make sure everything was tight and to wipe things down. Anyway, if you can change your oil this is simple, so don't be afraid of it ;^)

Doug

 

Just did my first transmission fluid change took about 15 minutes after finding the right bolts

Jack up driver front. removed A 15/16 plug bolt then check level just to make sure it the right hole the remove hex bolt drain in to pan lower car to finish draining. Then lift car install hex bolt I use pex 1/2 in pipe I just had it about 2 ft put in to 5/8 hole ( B ) about 3 inches it was tight added 4 WS ATF then when I pull out the pipe a few drip so put pan under and lower car now level wait Intel it stopped dripping then jacked up and installed 15/16 plug B lowered ran throw the gears worked fine . But a good thing my battery normal not green in the city driving now it is......
It just a faster was with 1 floor jack


Posted via the PriusChat mobile app.

 

You raised and lowered the car three times in the process? That's a work out!

Assume it's like third gen, ie: the correct level is established during refill by having the car level during the fill process, and filling till it starts coming back out. If that's the case, if there's a next time I would raise/level the whole car on jack stands. Or ramps in the front and jackstands in the back. And just leave it there for the duration of the drain and fill.

What's that publication btw, is it aftermarket? Maybe they've got a 3rd gen version, I'd be interested.

 

For all the diy'ers changing the trans fluid it forces you to put the car up pretty high. Take advantage of it. In addition to the trans fluid change I always service the under dash ac ecoil. There's a product called Kool It
On amazon that is a pressurized pleasant smelling microbial cleaner. First time u do it use 2 cans.Comes with rubber hose adapter you hook the can to the ac drip hose and shoot the contents up into the ecoil. Comes back out as water. Cleans the coils and removes mold and keeps the drip tube clean. Makes the car smell great and ac work much better. I also buy ac coil cleaner from HD and hose the front condenser down. Makes the ac super cold and extends the compressor life. Same thing the dealer uses.
Don't know where u live but down here a car with no
Ac is unusable.

 

What about the transmission cooler? Is it practical to drain the old fluid from the cooler on these?

 

There isn't a cooler, not a stock one.

The transaxle does have a coolant circuit and small rad for that.

 

Recently I did the required ATF inspection, and decided that the ATF required changing.

Miles on original ATF: 74,729 (120,264 km)

Miles on 2nd fill: 81,878 (131,770 km)

Miles on this fill: 107,785 (173,463 km)

Total miles: 264,392 (425,497 km)

Here are some pictures of the new vs. used ATF in little 50 ml bottles:

ATF-04 by Fred_H posted Jul 20, 2018 at 12:37 PM

ATF-03 by Fred_H posted Jul 20, 2018 at 12:31 PM

ATF-02 by Fred_H posted Jul 20, 2018 at 11:33 AM

ATF-01 by Fred_H posted Jul 20, 2018 at 11:29 AM

The magnetic drain plug had a layer of very fine black powder about 1 mm thick.

 

Not sure why, but they nixed the magnetic drain bolt on 3rd gen, at least in North America.

 

Will a Gen 2 drain plug fit a Gen 3? If not, I would recommend putting a high temperature grade cobalt samarium magnet in the inside end of the plug. I would not recommend neodymium, because it might begin to demagnetize if the transmission gets extremely hot. Does the Gen 4 have a magnetic drain plug?

 

Mendel, suppose a 1/2” NdB2 magnet cylinder would suffice?


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I'd be nervous to put anything remotely loose inside, and: I've changed the fluid on ours more times than I care to admit, think it's good.

 

If you place a 1/2” magnet disk to the outside of the nut, you’ll turn the nut into a magnet and be able to visually check it any time.


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