Should I change the transmission fluid at 25K/3 years of ownership, or not?

It's a good idea to do it if you plan to keep your car a long time or just like to take good care of machinery.

When you talk to your dealer if he tries to sell you an automatic transmission flush for $150-$200 he is either incompetent or dishonest and you should look elsewhere.

A fluid change on a Gen III is exactly like changing the fluid in a typical manual transmission except you use WS fluid.

 

Yes, I have replaced mine every 15k since new. Every 2-3 years or 30k is probably more than adequate.

Expect the dealer to charge you 1 hr labor ($120-$150) plus 4 qt of fluid at about $12/qt. Your dealer may have a discounted labor rate for fluid replacement services though, so ymmv.

 

Yes by all means change it every 25K. To make you feel better about spending $100 here's some pictures of Prius trans fluid samples:

The one in the middle is at 5,000 miles. My first change. The one on the right is at 25,000 miles and that's Redline D6 fluid.
The one on the left is virgin Redline D6.

You can clearly see how much wear is in the 5,000 sample. I change mine every 25,000 miles. Very very cheap insurance.

If you are very interested in your transmission's health I recommend you send out a sample of the used fluid to wearcheck.com They charge $25 and will tell you exactly how much wear is on that fluid. Looks really good at re-sale showing you paid so much attention to the car's maintenance. I make some good money when I sell my used cars with my maintenance records.

 

Your welcome.

Shouldn't be to bad. For the oil change bring them 4 quarts of Mobil 1 0-20. That's $30. Using the stock filter maybe $30 labor? Your good for 10,000 miles there. Trans fluid is maybe $80-100 labor plus $50 for the fluid. Good for 25,000 miles there. And tire rotation is maybe $25 so if its anymore than $250 all in go elsewhere. Don't buy anything else they offer either. No top end cleaner no injector cleaner no brake flush no nuthin'. Tell the service guy you want to tip the tech $20 so don't f*ck my car up. When he comes to you for his tip then you get to ask him any questions you want about the car. He'll treat you and your car real nice. Oh that brings the bill to $270.
Cheap.
Good Luck!

 

If they are using the Toyota 0W-20 oil in bottles, it's good oil. last I heard, in the US it's made by Mobil to Toyota's specs. If they are pouring oil out of a barrel, as far as I am concerned it's mystery oil.

 

They know or should know by now that the transaxle fluid needs changed sooner then the maintenance schedule. Just say you've seen pictures of burnt up MG2 motors so please change the fluid and here is a bottle, can you save me some of the fluid so I know what it looked like. Why would they care if you are willing to pay them to do it twice in the same period some people do it once?

There is only one possible fluid the ATF WS so it is really unlikely they screw it up.

 

I got my Trans fluid changed for $80, because I was quoted that on the phone. Apparently, when I took the car in, that was incorrect and they stated $160 (I think) for the Prius. Said something about the WS needed brought up to some temperature before doing it, yada yada yada. At that point, I pretty much told them that I wasn't going to do it at $160, and wouldn't have wasted my time coming in at that price. So she gave me the $80 as a "one time" item.

Next time, I'll follow the DIY that's somewhere on here for it and do it myself.

 

If the 2010 is anything like our 2009 it's even easier than an oil change since there isn't a filter to change.

2009 Procedures:
Chilton's Repair manual. Female hex plug drain (7mm?) and a male fill plug (21 or 24mm). 4 qts Toyota WS trans fluid. A funnel with about an 18" clear vinyl tube into the fill hole. A drain pan. Budget 30 minutes. A breaker bar would probably be a good idea. Torque plugs to 29 ft lbs.

I did our trans at 30k miles while the car was up on jack stands for tire rotation and oil change. The drained fluid was the nastiest stuff I've ever seen.

 

I changed mine at 25k and was surprised at how dark the fluid was compared to the new Toyota ATF-WS fluid. The used fluid came out with a really deep burgundy color, similar to the right hand photo from edthefox. The new fluid is a bright pink color like his left hand photo.

My car is coming up on 50k miles and I plan to change the fluid again at this time. It will be interesting to see how the 50k compares to the 25k.

I would advise, like others on here, that if you plan to keep the car for an extended period of time to change the transaxle fluid now.

 

There are millions of Prius owners that either stick to the manufacturers recommendations for fluid change intervals, or basically neglect them altogether that run just fine. Early transaxle fluid swaps are, I'm guessing, a priuschat creation. Toyota knows exactly what is going on in these transaxles, it's not some mystery that PC forum members have uncovered. If there was a benefit to an early fluid change, toyota would recommend it, and happily charge you for it. The fact is, Toyota does NOT recommend an early change, and in every instance reported here, Toyota service techs advise AGAINST a change.
There is no evidence presented here(nor can there ever be from this tiny sample size) that early fluid changes extend the life of your prius. There is also no significant incidence of transaxle failures appearing on this forum or anywhere else, so this is simply a fun (and wasteful) bit of tinkering that owners get to perform.

 

Read through the posts here, it's not that they don't "officially" recommend it, the don't unofficially recommend it either...when forum participants request this service(or to buy the fluids themselves) Toyota techs advise AGAINST it.
Now, one would think that a service person would see the value in performing so called "cheap insurance" fluid swaps(and enjoy the profits from same), yet they all(given what I read here) DON'T.

I would ask the service manager, and say that you hear conflicting reports about transaxle fluid swaps...I'd be curious to hear his reasoning for not performing a swap.

 

What's it gonna hurt to change it a X miles instead of 3x miles?

What's it hurt to change out any oil/lube at any given miles?

Those that accept the extra few bucks don't have a problem, why should anyone else?

Unless you can show harm, the cost/benefit ratio is a personal decision.

 

Lulz, take your time and research the subject thoroughly. Then make an informed decision. Either way is fine. Just don't let yourself be bulldozed by any particular side.

For my money, and it was, I did the lube change and feel absolutely fine about it. I know what I did and why I did it. When I got a look at the fluid after it all drained I was even more fine with it. Tickled to death, in fact.

Since it was only old fluid out and new fluid in, I can't imagine why anyone would have a problem about it.

Will the transmission last 500,001 miles instead of 500,000 miles? I don't know, I don't care. Is it a positive benefit? I believe so.

Does anyone agree with me? It doesn't matter.