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What does it mean since you claim to understand the data ... The bottom line is that you don't know. No one knows.
Since you've already answered your own question(s), presumably to your satisfaction, I will withhold further comment.
 

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Are there any such cases or reports of failed CVTs?
I take no responses and/or pointers to cases as a "no", there are no known cases of failed CVTs due to missed fluid changes.
But it could also be that I am just being ignored. :cool:
Everybody seemed kinda busy pointing out what people know or don't know, LOL.
 

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...Everybody seemed kinda busy pointing out what people know or don't know, LOL.
How exactly do you think one would put the blame squarely on the fluid change interval? Now, I do recall reading about the valve body failures of first generation Subaru CVTs, and there seemed to be a fair amount of anecdotal evidence to suggest that the fluid was a major factor. But, I suspect the only one able to answer your question with any certainty would be Subaru - after a teardown and thorough root cause analysis. Perhaps that's one reason why we've seen a lot of evolution in the CVT fluids over the years.
 

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How exactly do you think one would put the blame squarely on the fluid change interval? Now, I do recall reading about the valve body failures of first generation Subaru CVTs, and there seemed to be a fair amount of anecdotal evidence to suggest that the fluid was a major factor. But, I suspect the only one able to answer your question with any certainty would be Subaru - after a teardown and thorough root cause analysis. Perhaps that's one reason why we've seen a lot of evolution in the CVT fluids over the years.
Yeah, it's for sure not easy.
But if there would be many cases of CVT failures past say 120k miles, and all / most of them had never changed the fluid. Some statistical data like that.
 

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But it could also be that I am just being ignored. :cool:
I was tempted to write something earlier but was hesitant to get into it because there's no definitive proof of single-cause failure due to cvt fluid degradation. It took decades to "prove" the link between cancer and cigarettes.

It's easy to construct an argument for fluid changes no matter what they might be. Fluids do degrade and the degradation can be measured/monitored via services like blackstone, or even simple observation. It's not quite as solid to say exactly which changes would cause specific damage to the transmission, but in principle you need a balance between friction and lubrication, cooling, cleanliness, corrosion protection, hydraulic systems that can degrade from particulates flowing through it and enlarging orifices and such, the viscosity and other fundamental physical characteristics of the fluid can change with heat, time and shear.

Unlike motor oil, transmission fluids aren't subject to combustion byproducts or airborne particulates - it's pretty much a sealed environment, but it does visibly degrade either from the fluid itself degrading or the accumulation of wear particles.

In Canada the CVT fluid is supposed to be changed every 60k miles and in the USA it's lifetime, but the fluid and transmission are the same - made in japan and using the same fluids. These are policy/warranty decisions, not purely engineering ones. Another reasonable inference is that if Subaru USA says to change fluid every 25k if you frequently tow, then an occasional tow might merit changes at 50k or 75k, or no-towing at 100k. The powertrain warranty is 60k so anything beyond that is basically up to user discretion. Is 60k the definition of lifetime? That would match the Canada schedule. In general, severe service intervals are twice as frequent as non severe service. If severe service on a CVT has fluid changes at 25k then normal service being 50k is not unreasonable. 50k-60k seems reasonable for transmission fluid life in normal service.

None of the above is proof of anything and there are those who go 300k with no fluid changes so YMMV.

There's no proof that CVT's that never change their fluids last just as long as ones that do, or vice versa, and like cigarette studies - there are millions who smoked all their lives and never developed cancer, and people who never smoked who developed cancer.

It is said that absence of evidence isn't evidence of absence and that's where we are with this issue.

There's no proof that people who don't change their motor oil more than once a year have engine seizures but if we gathered aggregate data my bet would be that there's more bearing wear in engines that neglect oil changes, even though some engines with frequent oil changes end up with bearing wear for other reasons (detonation).
 

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I was tempted to write something earlier but was hesitant to get into it because there's no definitive proof of single-cause failure due to cvt fluid degradation. It took decades to "prove" the link between cancer and cigarettes.

It's easy to construct an argument for fluid changes no matter what they might be. Fluids do degrade and the degradation can be measured/monitored via services like blackstone, or even simple observation. It's not quite as solid to say exactly which changes would cause specific damage to the transmission, but in principle you need a balance between friction and lubrication, cooling, cleanliness, corrosion protection, hydraulic systems that can degrade from particulates flowing through it and enlarging orifices and such, the viscosity and other fundamental physical characteristics of the fluid can change with heat, time and shear.

Unlike motor oil, transmission fluids aren't subject to combustion byproducts or airborne particulates - it's pretty much a sealed environment, but it does visibly degrade either from the fluid itself degrading or the accumulation of wear particles.

In Canada the CVT fluid is supposed to be changed every 60k miles and in the USA it's lifetime, but the fluid and transmission are the same - made in japan and using the same fluids. These are policy/warranty decisions, not purely engineering ones. Another reasonable inference is that if Subaru USA says to change fluid every 25k if you frequently tow, then an occasional tow might merit changes at 50k or 75k, or no-towing at 100k. The powertrain warranty is 60k so anything beyond that is basically up to user discretion. Is 60k the definition of lifetime? That would match the Canada schedule. In general, severe service intervals are twice as frequent as non severe service. If severe service on a CVT has fluid changes at 25k then normal service being 50k is not unreasonable. 50k-60k seems reasonable for transmission fluid life in normal service.

None of the above is proof of anything and there are those who go 300k with no fluid changes so YMMV.

There's no proof that CVT's that never change their fluids last just as long as ones that do, or vice versa, and like cigarette studies - there are millions who smoked all their lives and never developed cancer, and people who never smoked who developed cancer.

It is said that absence of evidence isn't evidence of absence and that's where we are with this issue.

There's no proof that people who don't change their motor oil more than once a year have engine seizures but if we gathered aggregate data my bet would be that there's more bearing wear in engines that neglect oil changes, even though some engines with frequent oil changes end up with bearing wear for other reasons (detonation).
Statistics , in order to be accurate require a reasonably large statistical sample. That said, if you sample 10,000 car owners who did not change their motor oil, and 10,000 that changed it regularly, I would bet money the second group would have fewer engine related problems and fewer failures. That one case where a person who did not ever change their oil that never had a problem, really does not mean anything to anyone except that person. I think we are all in agreement, if you want fewer engine and transmission problems, you need regular oil changes.
 

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This thread's becoming a little contentious :). Since I saw a link from a Forester thread earlier, I assume it is OK to use a link to a BMW forum. Anyway, this is something I posted on Bimmerfest in 2010 (post #72). Also see the BMW response to a member voicing concerns in post #61. Separately, I am hesitant to believe the numbers on the virgin oil (CVT fluid) analysis posted on the FXT forum, i.e. with all wear metal levels at 0. I have never, and don't intend to ever do a fluid/oil analysis on our finite consumer fleet of vehicles. Folks are free to do as they choose.

UOA Discussion
 
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Yes, fair points about reporting, precision and test methodologies, I hesitated to bring that into this discussion of a $30 UOA. Still, rough trends are all most folks are looking for, and I've seen enough reports to have some faith that they can detect serious issues (there are at least a few threads in this forum, and plenty elsewhere, where UOAs have prompted members to pull things apart, often discovering a mechanical issue which was greatly accelerating wear).

...Separately, I am hesitant to believe the numbers on the virgin oil (CVT fluid) analysis posted on the FXT forum, i.e. with all wear metal levels at 0.
Understandable, but the results are remarkably consistent between that virgin sample analysis and the 3 UOAs I've seen for the HT-CVT fluid (one of which was posted by @Brucey). In each case, the reported values for B, Ca and P are ~200 ppm, ~300 ppm and ~600 ppm, respectively. Assuming they're not doctoring the numbers, that seems pretty encouraging for what they charge.
 

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This thread's becoming a little contentious :). Since I saw a link from a Forester thread earlier, I assume it is OK to use a link to a BMW forum. Anyway, this is something I posted on Bimmerfest in 2010 (post #72). Also see the BMW response to a member voicing concerns in post #61. Separately, I am hesitant to believe the numbers on the virgin oil (CVT fluid) analysis posted on the FXT forum, i.e. with all wear metal levels at 0. I have never, and don't intend to ever do a fluid/oil analysis on our finite consumer fleet of vehicles. Folks are free to do as they choose.

UOA Discussion
Its becoming contentious because there are a handful of members that will stop at nothing to enforce their opinions into every thread. If you dare to disagree with any of them they attempt to cancel you. This is supposed to be a discussion forum not a personal blog.
 

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Hmm, who's done that exactly, please reference posts? I haven't seen anyone attempt to "cancel" anything (the mods requesting that you follow forum etiquette is to be expected and was deserved, IMO).
All I was attempting to do was address your concerns by relaying my, admittedly basic, understanding of the spectroscopy results (I try to choose my words carefully to indicate my level of uncertainty). I'm not an expert on UOAs, but I have some limited professional experience, so I thought I could contribute something worthwhile even though my footnotes were not available.
 

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When I encounter threads that have a prevailing viewpoint that I disagree with, I just let it roll off my back. I could be wrong, I could be right, but ultimately no single person has enough data to say for sure (at least not enough for universal agreement). For example, using oem transmission fluid instead of aftermarket is something I say, but it's not because I have personally suffered from transmission damage from using non-OEM fluid - it's from extensive reading of other people's experiences and judging who is a credible source and who is not, by their body of work, and their ability to articulate their reasoning. Someone could say I'm just spreading hearsay. On the other hand if I damaged my own transmission with non-OEM fluid someone can also correctly say that my experience is just anecdotal and the failure could have been caused by some other issue and it was just coincidence that the non-oem fluid was used.

It can rub people the wrong way when someone spreads information that they think is disinformation and I get it. It's appropriate to question sources and methods, but embracing curiosity gains better responses than "PROVE IT!!!"

In the real world things aren't black and white. Data can be used selectively to support various conclusions and while the data may not be "fake" the manner in which conclusions are drawn from that data could be disingenuous or misinformed, connecting dots that shouldn't be connected or refusing to connects dots that should be.

Regarding blackstone - I will not be sending my CVT fluid to them - I'm just going to have the dealer change it when I feel like it would be a good idea, but my decision on when to change the CVT fluid could be informed by the blackstone results of other members, who spent the time and energy to do so. The calcium values aren't the most critical things I'd be looking for - they provide lots of different numbers. While blackstone provides commentary, ultimately it's up to the person getting the results to decode which numbers matter. Without having any special knowledge, I'd focus on viscosity and wear metals because it just makes sense. If a lubricating fluid loses viscosity it's a problem. If wear metals sharply increase it's a problem. I don't need to understand the function of Calcium in CVT fluid.

All understanding is incomplete understanding, but that doesn't negate the understanding that exists. No medication is absolutely perfect but we take it for its benefits despite its side effects, and it may work better for some people and not others for incompletely understood factors that could have to do with genetics, or diet or other factors - maybe even the manufacturing process. All decisions are made with incomplete information, but all you need is sufficient information to make a decision - you don't need complete information nor complete understanding.
 

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Let's remember an old saying too:

"There are lies, damned lies, and statistics."

One can make a convincing argument by playing with the numbers and how one present them.

As for me and my moderation:

Disagreement is encouraged but personal attacks are not. That's pretty simple right?
 

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Let's remember an old saying too:

"There are lies, damned lies, and statistics."

One can make a convincing argument by playing with the numbers and how one present them.

As for me and my moderation:

Disagreement is encouraged but personal attacks are not. That's pretty simple right?
Yes, its is simple however the moderators of this forum are failing to enforce this across the board. The moderators are clearly biased towards the higher volume posters. They refuse to hear new and forward thinking ideas. That's just not right. What this does is create a small group of egotistical posters that think they own the forum. It simultaneously discourages new membership and continued membership. Brucey, just look at the discussions, its the same 10 people making the postings. Anyone dare disagree with them, they are attacked by all of them. If you are going to talk about "lies, damned lies, and statistics," read all the posts, not just the ones from lower volume posters like me. .
 

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Yes, its is simple however the moderators of this forum are failing to enforce this across the board. The moderators are clearly biased towards the higher volume posters. They refuse to hear new and forward thinking ideas. That's just not right. What this does is create a small group of egotistical posters that think they own the forum. It simultaneously discourages new membership and continued membership. Brucey, just look at the discussions, its the same 10 people making the postings. Anyone dare disagree with them, they are attacked by all of them. If you are going to talk about "lies, damned lies, and statistics," read all the posts, not just the ones from lower volume posters like me. .
I am sorry that you feel that way but I am not seeing how your perception reflects reality. I have received your request that I ban you from this website and frankly you have done nothing to merit a ban. If you simply choose not to utilize the site anymore that is fine but I would hate for you to perhaps change your mind in the future and have to request that we reverse your self-imposed ban in the future.
 

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Yes, its is simple however the moderators of this forum are failing to enforce this across the board. The moderators are clearly biased towards the higher volume posters. They refuse to hear new and forward thinking ideas. That's just not right. What this does is create a small group of egotistical posters that think they own the forum. It simultaneously discourages new membership and continued membership. Brucey, just look at the discussions, its the same 10 people making the postings. Anyone dare disagree with them, they are attacked by all of them. If you are going to talk about "lies, damned lies, and statistics," read all the posts, not just the ones from lower volume posters like me. .
I disagree. I don't see any moderator bias.

I also don't see any refusal to hear new ideas. When one posts a new idea they have to be prepared that not all may agree with that idea.....and won't mind making their disagreement known.

I participate in many forums and all have a small contingent of regular posters. Might be why poster stats are kept and posted. I'm not sure how a group of regular posters discourages new folks from joining in the fun.

As for this thread and CVT fluid testing. Interesting to read but nothing I would ever consider.
 
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They refuse to hear new and forward thinking ideas.
"UOAs are meaningless" is a new and forward thinking idea? Come on man, the facts simply don't support that claim.

...Anyone dare disagree with them, they are attacked by all of them. If you are going to talk about "lies, damned lies, and statistics," read all the posts, not just the ones from lower volume posters like me. .
Sorry, but politely challenging an argument does not amount to a personal attack. If you'd like to invent facts and post them for all to see, while shielding yourself from any sort of critique, maybe consider a social media account with comments disabled.
 

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Maybe we should stop this discussion, but I really have a hard time seeing what zoulas did wrong.
Aside from asking to be banned, maybe, that seems a little uncommon. :oops:
 
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