Automatic transmission longevity: fluids & OCI
- Thread starter RPMster
- Start date
- Status
Originally Posted By: Quattro Pete
Maintenance schedule called for ATF replacement every 39K miles, and that's what was done, by the dealer.
I'm fairly sure MB calls for one change at 39k and lifetime fill after that.
Maintenance schedule called for ATF replacement every 39K miles, and that's what was done, by the dealer.
I'm fairly sure MB calls for one change at 39k and lifetime fill after that.
Originally Posted By: Quattro Pete
Wife's previous car was a 2008 MB C300 4matic. It was purchased in 2010 as a CPO vehicle with 20K miles on the clock.
Maintenance schedule called for ATF replacement every 39K miles, and that's what was done, by the dealer.
At 60K miles, the car needed a new transmission. Apparently, the trans itself was fine, but the AWD transfer case failed, and since it is integrated with the transmission, the whole transmission had to be replaced. From what I've seen reported on various MB forums, these 4matic transfer cases are known to fail prematurely in those model years.
Is the bearing broken , or gear teeth/others highly worn ?
How is it overcome in subsequent model years, if anyone has a clue ?
Wife's previous car was a 2008 MB C300 4matic. It was purchased in 2010 as a CPO vehicle with 20K miles on the clock.
Maintenance schedule called for ATF replacement every 39K miles, and that's what was done, by the dealer.
At 60K miles, the car needed a new transmission. Apparently, the trans itself was fine, but the AWD transfer case failed, and since it is integrated with the transmission, the whole transmission had to be replaced. From what I've seen reported on various MB forums, these 4matic transfer cases are known to fail prematurely in those model years.
Is the bearing broken , or gear teeth/others highly worn ?
How is it overcome in subsequent model years, if anyone has a clue ?
Originally Posted By: camrydriver111
Originally Posted By: Quattro Pete
Maintenance schedule called for ATF replacement every 39K miles, and that's what was done, by the dealer.
I'm fairly sure MB calls for one change at 39k and lifetime fill after that.
MB used to call for only one change at 39,000 miles (60,000 km), but they have since changed their minds about that
There are technical service bulletins advising dealers to change every 39k (60k km) now, even on vehicles that were originally spec'd for only one single change. So yes, every MB with the 7-speed auto or CVT (2006-2013 B-class, Canada-only) requires regular 39k changes.
Originally Posted By: Quattro Pete
Maintenance schedule called for ATF replacement every 39K miles, and that's what was done, by the dealer.
I'm fairly sure MB calls for one change at 39k and lifetime fill after that.
MB used to call for only one change at 39,000 miles (60,000 km), but they have since changed their minds about that
There are technical service bulletins advising dealers to change every 39k (60k km) now, even on vehicles that were originally spec'd for only one single change. So yes, every MB with the 7-speed auto or CVT (2006-2013 B-class, Canada-only) requires regular 39k changes.
Originally Posted By: zeng
Is the bearing broken , or gear teeth/others highly worn ?
It was the bearing. Here's an excerpt from the repair paperwork:
Quote:
How is it overcome in subsequent model years, if anyone has a clue ?
Not quite sure. Apparently later model years don't suffer from this issue, so MB must have made some change to the design, but I have no actual evidence to provide whether this is really true.
Is the bearing broken , or gear teeth/others highly worn ?
It was the bearing. Here's an excerpt from the repair paperwork:
Quote:
How is it overcome in subsequent model years, if anyone has a clue ?
Not quite sure. Apparently later model years don't suffer from this issue, so MB must have made some change to the design, but I have no actual evidence to provide whether this is really true.
In my opinion, most of the automatics I have seen fail were from the 70's thru the 80's. They seemed much improved after that. I am of the thought that the most important factor is the design. Some just have weak designs. The second most important factor is how they are driven. A teen can ruin an auto tranny in a summer of fun. IMO, far down the list is maintenance. Changing fluids is probably a good thing to do but will never overcome a poor design or a kid bent of squealing the tires. Personally I follow manufacturers spec on OCI so I seldom change my tranny fluid unless it looks bad or smells burnt.
Last edited:
In the old daze it was common to allow more value on a used car if it had an automatic. Stick was a deduction.
Our trucks usually make it to 200k miles before a rebuild. Then we install upgraded aftermarket parts and they will run virtually forever. But we have had factory units outlast the engine, too.
We typically drop the pan and change the filter once before 30k miles. Then it is strictly fluid exchange at the same intervals after that until failure...
Our trucks usually make it to 200k miles before a rebuild. Then we install upgraded aftermarket parts and they will run virtually forever. But we have had factory units outlast the engine, too.
We typically drop the pan and change the filter once before 30k miles. Then it is strictly fluid exchange at the same intervals after that until failure...
Originally Posted By: Quattro Pete
Originally Posted By: zeng
Is the bearing broken , or gear teeth/others highly worn ?
It was the bearing. Here's an excerpt from the repair paperwork:
Thanks for your solid feedback, Pete.
Assuming factory installation and materials were all proper including oil additives, personally I'm very wary of present trend of selecting ultra low viscosity oils for modern transmissions (automatic or manual,xfer case or diff),in terms of boundary/mixed lubrication regimes.
Originally Posted By: Quattro Pete
Originally Posted By: zeng
How is it overcome in subsequent model years, if anyone has a clue ?
Not quite sure. Apparently later model years don't suffer from this issue, so MB must have made some change to the design, but I have no actual evidence to provide whether this is really true.
Do you think MB TSB'ed a thicker viscosity transmission oil as the solution ? Would really appreciate your comments/findings on this or MB provide better 'superfinishing' on gear surfaces to accommodate ultra low viscosity oils ?? .....
Originally Posted By: zeng
Is the bearing broken , or gear teeth/others highly worn ?
It was the bearing. Here's an excerpt from the repair paperwork:
Thanks for your solid feedback, Pete.
Assuming factory installation and materials were all proper including oil additives, personally I'm very wary of present trend of selecting ultra low viscosity oils for modern transmissions (automatic or manual,xfer case or diff),in terms of boundary/mixed lubrication regimes.
Originally Posted By: Quattro Pete
Originally Posted By: zeng
How is it overcome in subsequent model years, if anyone has a clue ?
Not quite sure. Apparently later model years don't suffer from this issue, so MB must have made some change to the design, but I have no actual evidence to provide whether this is really true.
Do you think MB TSB'ed a thicker viscosity transmission oil as the solution ? Would really appreciate your comments/findings on this or MB provide better 'superfinishing' on gear surfaces to accommodate ultra low viscosity oils ?? .....
Last edited:
I apologise if someone else has already said this. The most important change is the first one, to get rid of all the build and break-in debris. When I have done this in the past with test vehicles we did a triple flush, usually around 10,000 miles. After that we actually ran some to up to 250,000, without another change and with absolutely no problems. The transmission is the most dirty when it's new.
Originally Posted By: zeng
Do you think MB TSB'ed a thicker viscosity transmission oil as the solution ?
Actually, just the opposite. Starting sometime in 2010, MB switched from ATF-134 type fluid (MB 236.14 spec) to ATF-134 FE type fluid (MB 236.15 spec) for these newer 7-speed 722.9 transmissions. The FE (fuel economy) is a lower viscosity fluid. 722.9 transmissions manufactured prior to 6/2010 are still required to use the older (non-FE) fluid.
Also, see my post in this older thread for more info:
http://www.bobistheoilguy.com/forums/ubb..._FE#Post2835225
As far as I know, the bearing failure I experienced wasn't attributable to the fluid. It must have been a manufacturing quality issue with the specific part/bearing. Majority of cars don't experience this issue, as far as I know.
Do you think MB TSB'ed a thicker viscosity transmission oil as the solution ?
Actually, just the opposite. Starting sometime in 2010, MB switched from ATF-134 type fluid (MB 236.14 spec) to ATF-134 FE type fluid (MB 236.15 spec) for these newer 7-speed 722.9 transmissions. The FE (fuel economy) is a lower viscosity fluid. 722.9 transmissions manufactured prior to 6/2010 are still required to use the older (non-FE) fluid.
Also, see my post in this older thread for more info:
http://www.bobistheoilguy.com/forums/ubb..._FE#Post2835225
As far as I know, the bearing failure I experienced wasn't attributable to the fluid. It must have been a manufacturing quality issue with the specific part/bearing. Majority of cars don't experience this issue, as far as I know.
I found phillip's comment most pertinent to my experiences in life.
I've had to work on two transmissions in my life.
An 81 LTD with an AOD and an 85 LTD with an AOD.
The later 4r70 (electronic) versions I've had were rock solid.
With the possible exception of the 95 t-bird which has a broken 1-2 accumulator spring (which was very common in the early days of the 4r70). Even the terrible torque converter shudder the 95 had when I bought it was solved with a simple fluid exchange (with Mobil 1).
I've had to work on two transmissions in my life.
An 81 LTD with an AOD and an 85 LTD with an AOD.
The later 4r70 (electronic) versions I've had were rock solid.
With the possible exception of the 95 t-bird which has a broken 1-2 accumulator spring (which was very common in the early days of the 4r70). Even the terrible torque converter shudder the 95 had when I bought it was solved with a simple fluid exchange (with Mobil 1).
Originally Posted By: Whitewolf
I apologise if someone else has already said this. The most important change is the first one, to get rid of all the build and break-in debris. When I have done this in the past with test vehicles we did a triple flush, usually around 10,000 miles. After that we actually ran some to up to 250,000, without another change and with absolutely no problems. The transmission is the most dirty when it's new.
Absolutely true. The overwhelming majority of debris from clutches etc is generated early in the transmission's life...
I apologise if someone else has already said this. The most important change is the first one, to get rid of all the build and break-in debris. When I have done this in the past with test vehicles we did a triple flush, usually around 10,000 miles. After that we actually ran some to up to 250,000, without another change and with absolutely no problems. The transmission is the most dirty when it's new.
Absolutely true. The overwhelming majority of debris from clutches etc is generated early in the transmission's life...
I had horrible experiences with AT's in the 80's and 90's:
'86 Toyota LE van - 80k before failure, ATF changes at the dealer at 30k and 60k
'85 Aerostar - failed and replaced under factory warranty and then multiple rebuilds (and an engine) before being retired at 180k.
'91 Chevy 1500 conversion van. First failure under warranty, multiple rebuilds before having a transmission shop put in a 'heavier duty' tranny which lasted forever, unfortunately I don't remember models
'89 Oldsmobile Touring sedan, tranny failed under warranty, but was repaired without a rebuild. Sold the car at 50k so I don't know how it lasted.
'04 Audi A4 - 12K on OE CVT, replacement lasted beyond when we sold it at 60k
Good cars:
'95 Nissan Maxima SE - sold the car with 150k fluid changed at 60k
'00 Nissan Maxima SE - sold with about 150k fluid changed at 60k
'00 Toyota Tundra, 220k no issues fluids changed every 40k
'05 Tundra sold with fewer miles, no issues
Current '06 Infinti FX45, 135k no issues, ATF exchange every 40k.
I have always done a lot of highway miles, always towed trailers (except for the Oldsmobile and Audi).
I have always, and still drive like a teenager. I have always at a minimum followed the mfg maintenance plans.
My other cars have been MT, which I have never had any issues with.
'86 Toyota LE van - 80k before failure, ATF changes at the dealer at 30k and 60k
'85 Aerostar - failed and replaced under factory warranty and then multiple rebuilds (and an engine) before being retired at 180k.
'91 Chevy 1500 conversion van. First failure under warranty, multiple rebuilds before having a transmission shop put in a 'heavier duty' tranny which lasted forever, unfortunately I don't remember models
'89 Oldsmobile Touring sedan, tranny failed under warranty, but was repaired without a rebuild. Sold the car at 50k so I don't know how it lasted.
'04 Audi A4 - 12K on OE CVT, replacement lasted beyond when we sold it at 60k
Good cars:
'95 Nissan Maxima SE - sold the car with 150k fluid changed at 60k
'00 Nissan Maxima SE - sold with about 150k fluid changed at 60k
'00 Toyota Tundra, 220k no issues fluids changed every 40k
'05 Tundra sold with fewer miles, no issues
Current '06 Infinti FX45, 135k no issues, ATF exchange every 40k.
I have always done a lot of highway miles, always towed trailers (except for the Oldsmobile and Audi).
I have always, and still drive like a teenager. I have always at a minimum followed the mfg maintenance plans.
My other cars have been MT, which I have never had any issues with.
In my none scientific experience transmission fluid changes have zero to do with transmission life. I have seen transmissions fail for all sorts of reasons, bad fluid is never one of them.
With modern transmissions fluid changes are just not necessary anymore, most are filled for life.
With modern transmissions fluid changes are just not necessary anymore, most are filled for life.
Last edited:
Lifetime fill is not a real thing. You're also accepting what the manufacturer considers the expected lifetime. It would be my goal to surpass that expectation if I were keeping a car. I expect most manufacturers only care if you make it out of warranty, not how you're doing at 200,000 miles.
The Accord in my signature has the original automatic. 380,000+ miles. I would guess it followed the factory suggestion for drains for the first half of it's life. (every 90k). Though it may have been changed more often.
I bought it at 194,000 miles from the original owner in 2004. It had a transmission slip from 3rd to 4th already and sometimes would seek on a downshift. I change the fluid with maxlife every 30,000 thousand miles. Just one drain and fill. It still behaves similarly, not much different then it was back then. I really ran the car HARD for years, I still do in comparison to how others drive. I have had a little grit in the pan after a drain a few times, little hard dark grey specs.
There was a period about 100,000 miles ago where I thought it was going to fail. I was driving it like I stole it everywhere and racking up a ton of miles with work and school. The trans started to hold gears longer and the 1-2 shift felt wrong. I drove it normally for a month or so and it went back to normal.
The Accord in my signature has the original automatic. 380,000+ miles. I would guess it followed the factory suggestion for drains for the first half of it's life. (every 90k). Though it may have been changed more often.
I bought it at 194,000 miles from the original owner in 2004. It had a transmission slip from 3rd to 4th already and sometimes would seek on a downshift. I change the fluid with maxlife every 30,000 thousand miles. Just one drain and fill. It still behaves similarly, not much different then it was back then. I really ran the car HARD for years, I still do in comparison to how others drive. I have had a little grit in the pan after a drain a few times, little hard dark grey specs.
There was a period about 100,000 miles ago where I thought it was going to fail. I was driving it like I stole it everywhere and racking up a ton of miles with work and school. The trans started to hold gears longer and the 1-2 shift felt wrong. I drove it normally for a month or so and it went back to normal.
My dads 01 Supercharged Frontier was bought new. Now with 262k the original transmission works perfectly. The pan has never been dropped. It has never been hooked to a fluid exchange or flush machine.
The first drain, and fill was done around the 30k mark. Since then I have tried to do it every 10k to 12k. Have used various Dexron 3 conventional fluids. Most of the time Castrol.
My mom has an 07 Altima with the CVT. Its been flawless as well with close to 130k. I do drain, and fills every 25k or so with Nissan CVT fluid.
The first drain, and fill was done around the 30k mark. Since then I have tried to do it every 10k to 12k. Have used various Dexron 3 conventional fluids. Most of the time Castrol.
My mom has an 07 Altima with the CVT. Its been flawless as well with close to 130k. I do drain, and fills every 25k or so with Nissan CVT fluid.
Originally Posted By: MolaKule
JustinH said:Toyota says not to change the fluid in my 2010 Rav 4.
...drive like this 90 year old gray-hair in front of me.
Uh...you were surfing the net and posting this reply while driving? Just womdering
Originally Posted By: JustinH
Toyota says not to change the fluid in my 2010 Rav 4.
Not necessary.
I dumped the fluid at 80k and it was black, and there was sludge in the bottom of the pan.
Takes 4 quarts of fluid, I will be doing it once every couple years.
will be doing this myself soon -- I bought the car with 85k on it, doubt it's ever been done
Originally Posted By: MolaKule
Originally Posted By: meborder
When you say drain and fill, are you just referring to the pan?
There are two schools of thought.
One is to drop the pan, clean it, replace the filter if it has one, and add enough replacement fluid to place the fluid between the hash marks when hot.
Advantage: This allows a slow cleaning process to occur. Disadvantge: You have to do this three or more times to get a majority of new fluid introduced. Good for the do-it-yourselfer.
The other is a complete drain and refill via a machine that uses the AT pump (while engine is running) to suck in new fluid while "purging" the old fluid. Advantage: This process allows the torque converter fluid to be purged as well, in real time. Disadvantage: One time cost is higher since you pay for the labor, machine pay-off, and fluid. Generally not for the do-it-yourselfer.
Now some do-it-yourselfer's will identify the low pressure (intake) hose and the high pressure (output hose) at the radiator, disconnect it, and do their own complete drain and refill using the AT's own pump.
this is what I will be doing - I don't have a pump, when I did this on the corolla I turned the car on and off. I think that's what the bottom part of your quote is saying. drained like a quart at a time, would refill, repeat.
Originally Posted By: akela
The dramatic change is what poses a risk, I guess.
The transmission likes when the fluid properties are stable. And doesn't like when they suddenly change - the mechanism needs to re-adjust, at a cost.
is this true?
Toyota says not to change the fluid in my 2010 Rav 4.
Not necessary.
I dumped the fluid at 80k and it was black, and there was sludge in the bottom of the pan.
Takes 4 quarts of fluid, I will be doing it once every couple years.
Originally Posted By: MolaKule
Originally Posted By: meborder
When you say drain and fill, are you just referring to the pan?
There are two schools of thought.
One is to drop the pan, clean it, replace the filter if it has one, and add enough replacement fluid to place the fluid between the hash marks when hot.
Advantage: This allows a slow cleaning process to occur. Disadvantge: You have to do this three or more times to get a majority of new fluid introduced. Good for the do-it-yourselfer.
The other is a complete drain and refill via a machine that uses the AT pump (while engine is running) to suck in new fluid while "purging" the old fluid. Advantage: This process allows the torque converter fluid to be purged as well, in real time. Disadvantage: One time cost is higher since you pay for the labor, machine pay-off, and fluid. Generally not for the do-it-yourselfer.
Now some do-it-yourselfer's will identify the low pressure (intake) hose and the high pressure (output hose) at the radiator, disconnect it, and do their own complete drain and refill using the AT's own pump.
this is what I will be doing - I don't have a pump, when I did this on the corolla I turned the car on and off. I think that's what the bottom part of your quote is saying. drained like a quart at a time, would refill, repeat.
Originally Posted By: akela
The dramatic change is what poses a risk, I guess.
The transmission likes when the fluid properties are stable. And doesn't like when they suddenly change - the mechanism needs to re-adjust, at a cost.
is this true?
Last edited:
MolaKule
Staff member
Originally Posted By: willbur
Originally Posted By: MolaKule
Originally Posted By: MolaKule
JustinH said:Toyota says not to change the fluid in my 2010 Rav 4.
...drive like this 90 year old gray-hair in front of me.
Uh...you were surfing the net and posting this reply while driving? Just womdering
I never ever text and drive and it was posted from home.
I did have an older lady in front me before I got home, hence the sarcasm, but thanks for looking out for me.
- Status
