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

There is no removable transmission pan in a Gen2 Prius. There was one in the Gen1. I don't know about the Gen3 or other models ("C", "V", Plug-in)... yet.

JeffD

 

I don't know of any of Toyota's hybrid specialists that can't properly do their job(s) above - and in fact, they would be quickly transferred to jiffy lube for doing those kinds of acts / omissions. But the irony to me is how some complain they're being hosed, when (excess) services are 'recommended' and yet others insist on changing plugs, oil, coolent, etc - at a 300% or higher frequency than necessary. Yep never mind the waste - to each his own.

SGH-I717R ? 2

 

yes, I get this, I was using an oil change term but there must be some sump or area in the bottom of the TA where particles are going to settle.

 

They settle on the dump bolt MAGNET and remain there till cleaned off. Of course over 100,000 miles I would imagine there's quite a clump at the end of the magnet rendering it useless.

I love how you can lecture us about the proper way to take care of a manual trans and you really don't know the first thing about it. Never worked on one, Never saw the inside of one and never had to replace one. If you did any of those 3 you would do all the easy things you could during its life to not end up having to do any of those 3 things. Cause it sucks.
And if you can't do it yourself its really expensive. I maintain my trans out of fear. Fear of emptying my wallet and fear of wasting my time with my car down. I don't enjoy it. It hurts. But I have seen the inside of an engine and a trans thats has not been taken very good care of. And I intend to keep the car 200K+ miles. I know it will hit that easily with no drama.

When I go to sell my car and show the prospective buyer its maintenance record I'll bet my life that guy won't argue with me or call me ridiculous. Or wasteful. Or doing it for recreation.

 

Changing the Prius transaxle fluid at 30,000 or 60,000 miles is just another case where the cost to do it is low ($35-DIY; approx. $100-dealer) and the potential benefit, although not quantifiable, of lowering the risk of major repair (up to $6,000) is high. It is a classic case of "penny-wise and pound foolish" to argue against doing this.

 

I spent a good bit of time today at my local dealership, specifically looking into the maintenance work I should have done on my care when it hits 60,000 miles (I'm just under 59,000 today). I asked specifically about the transaxle fluid, and the service writer said he couldn't find any recommendation to have it changed. I asked to speak to the Prius service guys -- the ones who actually do the work. Eventually, they brought out a guy who'd been working at the dealership for 10+ years.

The service tech said there was no need to do it. I told him I thought I'd have the car to 150,000 miles, so wouldn't it make sense to change it now and get 90,000 more on it than to wait 40,000 and get only 50,000 later, with the chance of additional wear and tear. He looked at me, oddly, and said there's never really a reason to do it unless you have a known problem. I kept pushing him, nearly begging him to do the work, and he said he would do it -- no danger and no great cost (but more than $100, for certain) -- but he said he wouldn't do it if it were his car. At this point, he decided to say that he would change the oil at 5,000 and not 10,000, despite what Toyota said, but that this was only his personal decision and not something he recommends. Again, he said he knows there is very little wear on the engine, and he only changes the oil because it makes him feel better. At the very end, with a handshake and smile, he said: "Let's talk about this again when you're at 80,000."

Before that point, we also had talked about other Prius maintenance issues. I asked about struts, tie rods, etc., and he said "No. Nothing. The Toyota suspension systems amaze me." At that point he said: "Mice. That's the real problem."

So, I'll go in and have a thorough inspection, making certain they understand I'll order up the work if it is needed and fits within the 60-month, 60,000 mile warranty, and I'll have them change out the air filter and cabin filter (the air filter was still VERY clean at 50,000; I think I changed it at about 25,ooo or 30,000, but I can't recall). I may also have them do the oil this time, since they'll have it up on a lift.

Interesting Time. I really tried to get them to sell me the service, but they just didn't think it was necessary. They weren't trying to argue with me or steer me away from it. They wanted me to be happy, so they'd do the work, but they suggested waiting another 20,000 miles to consider the question again.

 

The response you received from the dealer is not unusual. They "officially" do not recommend changing fluids more frequently than the manufacturer's scheduled intervals because: 1) to do so puts them in conflict with the manufacturer's marketing policy, i.e. our brand needs less maintenance than the other brands; 2) changing fluids is a low profit operation; 3) the dealer would much rather perform a high profit repair or replacement. I am not necessarily faulting the dealer on this. It is just the nature of their business, but don't be a victim of it. Changing your transmission fluid at 30,000 or 60,000 mile intervals is still the best strategy if you want to minimize the risk of costly repair/replacement.

 

I did a quick internet search to see what others have found when analyzing ATF fluids, manual transmission oils and differential oils. Some excerpts:

2006 Tundra automatic trans., WS-ATF fluid, 57,000 miles on factory fill: 40ppm iron

2006 Mini, manual transmission, 52,000 miles on factory fill: 213 ppm iron

BMW 335i, final drive, 33,000 miles on factory fill: 284 ppm iron

BMW 335i, automatic transmission, 33,000 miles on factory fill: 33 ppm iron

MB C230, final drive, 60,000 miles on factory fill: 290 ppm iron

So it appears that 200+ppm iron is typical for a gearbox containing only gears and bearings, while conventional automatic transmission levels are much lower. I would hazard a guess that conventional automatic transmissions show the lower iron levels due the presence of an oil circulating pump and filter, and not because of lesser wear. I think we can also say that the iron levels found when Prius owners have had their factory fill transaxle lubes analyzed is not unusual.

ConsumerReports, for all Prius years, reports "much better than average" reliability for Transmission Major, Transmission Minor and Drive System. So it seems that the Prius transaxles are tolerant of dirty, iron-particle containing oils? Perhaps Toyota doesn't recommend a change since the risk of refilling with the wrong oil is worse that retaining the correct oil with iron particles?

 

I appreciate both of these comments, and I'm very glad to see a little bit more research on the question than I've attempted.

To be clear: The guy I talked to in the service department didn't recommend it, but he also didn't try to talk me out of anything. When I asked whether there was any real "danger" in doing it, he thought it would be relatively risk free and would be of value if it offered me some comfort. He just thought it would be a waste of dollars and thought that if I was going to drive the car to 150,000 miles, I should change it at 80,000 and not now (60,000).

Also, remember that the same man suggested changing the oil at 5,000-mile intervals instead of the Toyota recommended 10,000-mile periods. He said it wasn't a "recommendation" but simply his personal preference.

 

The typical failure mode in the Gen1 trans. was breakdown of MG winding insulation. This failure mode is what prompted Bob Wilson's ATF study on Gen1's and then mine in support of his efforts on Gen2's (my 2004). There have been a small number of trans. failures reported in Gen2's, but I haven't seen postmortem analysis of those units. Whenever the owners of those were asked if they did ATF refreshes, the answer was uniformly no.

Since it is common for many manufacturers to have auto trans. failures at 100k to 200k miles and I plan to keep my 2004 Prius running past 300k miles (currently at 228k miles), I'll continue to refresh my ATF every 60k miles. As others have noted, it is inexpensive insurance.

Don't bother me about the ecological waste. One gallon of ATF every 60k miles pales in light of a gallon of engine oil every 5-10k miles and of course about 1200 gallons of gasoline in that same period.

JeffD

 

I appreciate your word on this question.

Haven't heard from Bob, have we? How long before he finds this question and gives us his take on things?

 

I stop by the Dealer today and ask the Service write about doing this change and he inform me it would be 149.00 and that the mechanic would need to hook up the car to the computer to preform the changing the fluid. the mechanic needed to monitor the the tranny fluid when doing this. Any comment, I never heard anything about doing this in this thread . or is this just another miss inform service writer

 

The dollar figure isn't too bad, considering the very high cost of the fluid, but I'd like to see it for just a little bit less money. I don't know about hooking the car up to a computer, but I'm certain they would want to analyze the fluid in some fashion.

 

This refers to the fluid level check procedure for late model conventional automatic transmission and transaxles.
The trans fluid temp is monitored with the Techstream scantool, and the fluid level is checked within a narrow temp window.
This has nothing to do with the Prius transaxle.
The Prius transaxle is more like a manual trans when it comes to draining and refilling the fluid.

 

Just to reinforce what is above, The Prius Trans. does NOT have an ATF level sensor! So the scan tool cannot read the level and your dealer is using a generic ATF refill job statement that is appropriate for some other Toyota models.

This is a generic dealer problem and usually comes with an option to do the "more complete" transmission flush which they can't do at all in a Prius even though they will price it higher. You should be able to get a dealer to do a drain and refill for about $100 in a Prius (mine in CT does).

JeffD

 

So the service manager says don't bother, then the tech with 10years experience says "don't bother'". The customer keeps pressuring the tech and the tech says he wouldn't even do it in his OWN vehicle. so they don't "officially" recommend it, and they don't even "unofficially" recommend it.
The dealer would rather ONE transaxle swap than dozens and dozens of TA fluid swaps!!?? Changing fluids is a LOW profit item? at $149 for one hours labor and $20 of fluid? for techs who are otherwise sitting around waiting for TA failures that are NOT happening??

"Changing your transmission fluid at 30,000 or 60,000 mile intervals is still the best strategy if you want to minimize the risk of costly repair/replacement." Please provide ANY evidence to back up this statement....it's simple, show the failures reported here, and if the owner did/not perform fluid swaps. How about just ONE? Nobody here can even post anecdotal information that anyone who's ever turned a wrench for Toyota that has said an early TA fluid swap is the "best strategy".

People constantly complain about overcharging and unnecessary services performed by dealers....but in THIS case, when customers go begging for this service, the great Toyota conspiracy among service managers forces them to talk customers OUT of this particular $149 swap? Don't trust service depts when the recommend service, but don't trust service depts when they don't recommend service. On one hand they're trying to screw you, on the other hand they're putting off screwing you for years, for major service that will very likely never be required. makes perfect sense.

 

Over and over again, the dealers quote and describe a full auto tranny service, not even realizing it is a simple drain and fill, yet you trust them when they say it is magic fairy fluid that never wears out. It is your money. For my money, I will change the fluid at reasonable intervals until Toyota extends the warranty to forever, or publishes a change interval.

 

I'm not trying to engage in an argument over this, but I do want clarity: The reference Schorert makes is to my conversation with the Toyota service people who clearly were discussing with me the very simple process of draining the ATF and replacing it. Whether others are being mislead or are participating in blind conversations, I was not. It is simply a conversation I had with a hybrid tech guy at my local dealership. As far as I can tell, it is entirely my choice whether to spend $100-$150 on a change, and the tech will do it if I ask. Toyota has had their problems with sludging in their engines, so I think they would be very pleased to recommend a service interval for the transaxle fluid as a way to avoid new claims concerning recommended maintenance. Me? I'm still thinking it doesn't hurt to change the fluid, and I'll likely do it either at 60,000 or 80,000.

 

I understand, a priori, I just try to balance Mr One Issue To Post About Ever.

 

I have just removed the bottom panel to check my trans fluid. I removed the bolt next to the drive shaft with a 10 mm hex and breaker bar. It came off without a problem. I stuck my finger in the hole to check the level and it was filled right to the bolt level. I also examined the fluid and noticed it was very clean and pink. I have 32k and the fluid looks new. I am going to button her up and wait till 60k to check again.