Why changing trans fluid is so critical

[MolaKule]

Originally Posted By: 69GTX
Who is the person responsible for tracking a transmission with lifetime fluid through its entire life including all the various owners? That means until the boneyard or the transmission fails or is rebuilt...whichever comes first. Where can I find this data to gauge the effectiveness of lifetime fluids? How does a lifetime fluid work if a particular owner beats the snot out of their engine and transmission with jack rabbit starts and stops, burnouts, extended high rpm runs, etc? Or is it the case that only engines are susceptible to "severe" service?

What does "lifetime" mean? First owner? Warranty period? Up to 100K-150K miles? 200K miles? 300K miles? Unlimited?

I think Lifetime means until the warranty period has expired.

Quite frankly, I don't think we formulators or additive suppliers are at the point of developing "Lifetime" fluids with the current technologies.

 

[69GTX]

Originally Posted By: MolaKule
I think Lifetime means until the warranty period has expired.

Quite frankly, I don't think we formulators or additive suppliers are at the point of developing "Lifetime" fluids with the current technologies.


Good to know MolaKule.

What about a "remaining lifetime" fluid after all the break-in material is removed following the first fluid change? What if that stuff were removed at 10K miles? Of course, if they don't allow owners to get access to the transmission fluid & filter, then it doesn't matter.

 

[Leo99]

Originally Posted By: Kestas
Originally Posted By: Leo99
Where/how do you see bearings with debris denting?

I don't understand the question. These are transmission bearings bathed in transmission fluid.


You wrote: "All to [sic] often I see shortened life with bearings due to debris denting."

I asked where and how do you see this. Do you take transmissions apart to see the bearings? What are the circumstances where you see these damaged bearings?

 

[WhizkidTN]

Originally Posted By: Leo99
Originally Posted By: Kestas
Originally Posted By: Pop_Rivit
Originally Posted By: Leo99
Where is the data that changing out lifetime fluid extends the life of the transmission?


How dare you actually ask for data. A Youtube video on a discussion forum is all the proof you need.

Well, this time Leo is lucky. I happen to see the results of bearings tested in transmissions designed with fill for life fluid. All to often I see shortened life with bearings due to debris denting. The manufacturers are all moving toward fill for life, and it's an uphill battle. They are now developing programs where suppliers have to guarantee a certain amount of cleanliness of their parts that end up in the lube cavity. Whenever I get their attention I emphasize the importance of a fluid change to clean out the breakin debris. Unfortunately, the manufacturers are catering to to fickle and lazy public who can't be bothered with flushing out the breakin debris, which would cure many ills as it has in the past.

Mercedes had fill for life some 15 years ago. They ended up with many unhappy customers with transmissions that couldn't last. Mercedes later modified their maintenance schedule by specifying a change at 40K, then filled for life ( or more realistically, every 100K).


Toyota hasn't changed their recommendations. Guess they're not seeing the failures that Mercedes saw. Different fluid and different transmissions. Straw-man argument. Where/how do you see bearings with debris denting? Does this shorten the life of the AT? Where are all these broken transmissions if the fluid is only good for the extent of the warranty period? Talked to some folks that drive late model Hondas and they're up over 150k miles and they've never touched their ATF either.


FWIW: My 2002 Honda Odyssey mini-van had it's transmission fluid changed at 87K (fluid was black/brown and gritty) and 130K with synthetic ATF as well as had a Magnefine in-line filter installed. I even changed the "unknown" fluid filter (lifetime filter) on top of that 5-speed transmission. It had several TSBs and even had the dealership alternate oil port installed to help fix a design defect. It finally died at 156K miles in 2014 and I traded for my wife's '14 Nissan Rogue. I bought the van used at 85K miles so I have no idea how it was treated prior to my ownership.

My point: The Honda ATF (and any ATF really) needs to be changed if you want the vehicle to last and last. Honda did have a schedule for changing the ATF in the manual but I don't remember what it was. It might have been 90K miles but it was never a "lifetime fluid". Honda (and Acura) had a terrible time with their transmissions in the mid-2000s.

 

[WhizkidTN]

I've owned five cars that I purchased used (some very used and cheap) that died or got quickly sold/traded due ONLY to their automatic transmission going out. The rest of the car was basically fine. That was even with me babying the cars and doing excellent maintenance on the ATF to boot. I HATE them! So for my cars I bought new, I'm making sure I do this right (ATF fluid changes, diff gearbox oil changed, etc.) with either factory or aftermarket full synthetic fluids from the get-go so that I can get 250K+ miles out of them if I choose.

Those five car?
1992 Plymouth Grand Voyager (5 transmissions in total - I was stupid to keep going on this one), sold at 258K miles.
1993 Dodge Grand Caravan SE (2 transmissions in total), sold at 221K miles.
1998 Nissan Maxima SE (Original transmission), towed away at 250K miles.
2002 Honda Odyssey EX-L (Original transmission), towed away at 156K miles.
2002 Kia Optima EX (Original transmission), towed away at 134K miles.

 

[JHZR2]

Originally Posted By: Kestas

But to suggest transmission fluid doesn't degrade and that there is no benefit from changing transmission fluid is ignorant and irresponsible.


+1. It's as simple as the fact that fluids oxidize, and dispersants and other additives get used up. Lifetime is subjective, and statistical lifetime is not what everybody desires in terms of vehicle longevity.

 

[R18Civic]

Even a severely abused transmission will make it past 100k miles with regular fluid changes.

Every time you overheat a tranny you effectively cut the remaining life of the transmission in half, if the fluid is burnt and black its too late to change.

 

[Leo99]

Originally Posted By: Hemispheres
Even a severely abused transmission will make it past 100k miles with regular fluid changes.

Every time you overheat a tranny you effectively cut the remaining life of the transmission in half, if the fluid is burnt and black its too late to change.


In half? And you know this how?

 

[R18Civic]

Originally Posted By: Leo99
Originally Posted By: Hemispheres
Even a severely abused transmission will make it past 100k miles with regular fluid changes.

Every time you overheat a tranny you effectively cut the remaining life of the transmission in half, if the fluid is burnt and black its too late to change.


In half? And you know this how?


Automotive Technology: A systems approach 5th Edition, the manual and automatic transmission instructor at my local community college made sure to reiterate that bit of info.

 

[Leo99]

Originally Posted By: Kestas
But to suggest transmission fluid doesn't degrade and that there is no benefit from changing transmission fluid is ignorant and irresponsible.

And to suggest that changing lifetime ATF has a benefit without any data to support that it is beneficial also ignorant and irresponsible. Prove it makes a difference. Because it feels to you like it should is not proof.

My main beef is with the title of this thread. "... so critical" I contend it's not critical at all for lifetime fluids. I'm open minded. Show me the data that changing out a lifetime fluid provides a benefit.

 

[R18Civic]

Just because it has lifetime fluid means little to nothing, sealed transmissions contain no filter, usually just a screen on the pickup. A transmission flush done every 50-100k can't hurt, only help

 

[Leo99]

Originally Posted By: Hemispheres
Originally Posted By: Leo99
Originally Posted By: Hemispheres
Even a severely abused transmission will make it past 100k miles with regular fluid changes.

Every time you overheat a tranny you effectively cut the remaining life of the transmission in half, if the fluid is burnt and black its too late to change.


In half? And you know this how?


Automotive Technology: A systems approach 5th Edition, the manual and automatic transmission instructor at my local community college made sure to reiterate that bit of info.


The book you referenced says a 20°F increase over 175°F in operating temperature will decrease the life of ATF by one-half. That's pretty severe degradation. Also a broad statement given the various types of ATF in use. But the book does say it.

 

[R18Civic]

Yeah things can get nasty quickly. The only fluid I could recommend for very long intervals is amsoil. They came in and basically had a chart of all mfr atfs. Dex VI is near the top. Last place goes to Honda which makes sense given their AT trans failure rate.

Of course amsoil is up top. The test procedure was nonstop WOT operation until transmission had overheated, then tested the fluid.

 

[davison0976]

Originally Posted By: 69GTX
What does "lifetime" mean? First owner? Warranty period? Up to 100K-150K miles? 200K miles? 300K miles? Unlimited?


According to the video, at 6:40, "lifetime" is 150K miles.

 

[JHZR2]

Originally Posted By: Leo99
Originally Posted By: Kestas
But to suggest transmission fluid doesn't degrade and that there is no benefit from changing transmission fluid is ignorant and irresponsible.

And to suggest that changing lifetime ATF has a benefit without any data to support that it is beneficial also ignorant and irresponsible. Prove it makes a difference. Because it feels to you like it should is not proof.

My main beef is with the title of this thread. "... so critical" I contend it's not critical at all for lifetime fluids. I'm open minded. Show me the data that changing out a lifetime fluid provides a benefit.

You using the term "lifetime" in asking for proof shows that you're asking an invalid question.

We understand full well as a universal basis of physical chemistry, that things will react, and the more time at temperature, the more and faster they will do so. Since this is an oxidizing environment, and we know that oxidation causes changes to the base fluid, this must be met with shearing in order to stay in a viscosity range. If we're going to claim an oxidation resistance or antioxidant doing, then again, lifetime must be defined properly.

But since you have not qualified "lifetime", it would be impossible to provide proof, even if there was some to be had.

And what metrics? Shift feel? Bearing tolerances and wear? Something else?

 

[Shannow]

Originally Posted By: Leo99
Originally Posted By: Kestas
But to suggest transmission fluid doesn't degrade and that there is no benefit from changing transmission fluid is ignorant and irresponsible.

And to suggest that changing lifetime ATF has a benefit without any data to support that it is beneficial also ignorant and irresponsible. Prove it makes a difference. Because it feels to you like it should is not proof.

My main beef is with the title of this thread. "... so critical" I contend it's not critical at all for lifetime fluids. I'm open minded. Show me the data that changing out a lifetime fluid provides a benefit.


Kestas does bearings...roller bearings that go into all sorts of things... like transmissions.

Kestas does failure analysis and makes recommendations for the use of roller bearings in a wide variety of problematic applications.

IF Kestas says that he's seen debris denting, and has made recommendation that the initial wear in debris should be removed via fluid replacement, then I tend to listen rather than berate him.

What's YOUR data ?

"not much seems to blow up"...it's becoming the new BITOG proof of performance on a range of topics.

Originally Posted By: Leo99
Originally Posted By: Leo99

In half? And you know this how?
... The book you referenced says a 20°F increase over 175°F in operating temperature will decrease the life of ATF by one-half. That's pretty severe degradation. Also a broad statement given the various types of ATF in use. But the book does say it.

That's pretty well what happens with any lubricant at temperature.

10°C more halves the oxidation life. (Yes, before you pick on that, 10°C is 18°F).

 

[DoubleWasp]

Originally Posted By: Leo99


Where is the data that changing out lifetime fluid extends the life of the transmission?


Aside from the massive amounts of internal component failures caused by dirty transmission fluid?

Aside from the numerous manufacturer service manuals that list dirty transmission fluid as a cause of transmission problems in diagnostic flow charts?

 

[DoubleWasp]

Originally Posted By: Leo99
Originally Posted By: Kestas
Originally Posted By: Pop_Rivit
Originally Posted By: Leo99
Where is the data that changing out lifetime fluid extends the life of the transmission?


How dare you actually ask for data. A Youtube video on a discussion forum is all the proof you need.

Well, this time Leo is lucky. I happen to see the results of bearings tested in transmissions designed with fill for life fluid. All to often I see shortened life with bearings due to debris denting. The manufacturers are all moving toward fill for life, and it's an uphill battle. They are now developing programs where suppliers have to guarantee a certain amount of cleanliness of their parts that end up in the lube cavity. Whenever I get their attention I emphasize the importance of a fluid change to clean out the breakin debris. Unfortunately, the manufacturers are catering to to fickle and lazy public who can't be bothered with flushing out the breakin debris, which would cure many ills as it has in the past.

Mercedes had fill for life some 15 years ago. They ended up with many unhappy customers with transmissions that couldn't last. Mercedes later modified their maintenance schedule by specifying a change at 40K, then filled for life ( or more realistically, every 100K).


Toyota hasn't changed their recommendations. Guess they're not seeing the failures that Mercedes saw. Different fluid and different transmissions. Straw-man argument. Where/how do you see bearings with debris denting? Does this shorten the life of the AT? Where are all these broken transmissions if the fluid is only good for the extent of the warranty period? Talked to some folks that drive late model Hondas and they're up over 150k miles and they've never touched their ATF either.


You're seriously using honda transmissions as an example of transmissions that go the distance? Many of them had 3 transmissions before the warranty expired. I'd bark up another tree if I were you.

 

[Pablo]

2006 Honda Odyssey. Full Amsoil ATF changeover within the first 10K miles. Fast forward to 2017, 170,000+ miles. Same Amsoil fluid fill. Although the body is beat, interior is just shredded from use, wheels uglier than my posterior - the van still drives and shifts like new. ZERO transmission issues. I'm not going too bother changing the fluid. This year we will get another car, but probably will keep the van.

 

[zzyzzx]

Originally Posted By: Leo99
Where is the data that changing out lifetime fluid extends the life of the transmission?


Viscosity of your transmission fluid changes some over time, which sometimes causes problems (usually old fluid causes low transmission oil pressure). That, and small particulate matter accumulates in the fluid, which essentially sandblasts the inside of your transmission over time, which is probably also bad. I've seen plenty of reports on the internet of high mileage transmissions with small problems solved by a fluid and filter change.

If you are only intending to keep your transmission for 100K miles, then yes, it's lifetime fluid. I have a car with 238K miles on it's original 1995 automatic transmission (a F-4EAT) and yes I change the fluid.