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ATF change at 30K really?

I’ve seen several recommendations here to change automatic transmission fluid as often as 30K, no matter what the manufacturer recommends. My Ford Fusion recommends changing at 30K for special service conditions but 150K for normal use, and there’s no way my driving, which includes a daily 15 mile (each way) commute on a flat, uncrowded highway, could be considered severe service. I know that manufacturers want to make it seem like their cars are low maintenance, but a 5-fold difference, really? Can the manufacturer be that wrong?

The manufacturer wants it both ways. They advertize “low maintenance”, but then add the special conditions, so that the product will last if properly maintained. If Volkswagen was that honest, they would have fewer pre-mature transmission failure.

There are many posts here that deal with engines and transmssion failure as spelling the end of the car’s life. Avoiding those major failures is the key to long car life.

So, if you tow a trailer or spend all day in city traffic, you MUST change the fluid every 30,000 miles. However, with your type of driving, if you don’t change it, your car 's transmission may only last 160,000 miles, instead of 300,000 miles, which is the design life of the car.

Most car owners who trade often like these long intervals; it allows them to do virtually no maintenance and everything will last at least as long as the warranty. They leave the breakdowns for the next guy.

Car maintenance is a lot like maintaining your teeth! Even with little care they’ll look great till age 35. If you want them to last a lifetime, take good care of them!!

Notice the five fold difference between regular and “severe” service in the Ford maintenance schedule?

Now read what constitutes “severe service.” Many of us fall somewhere in between.

30K ATF fluid changes are cheap insurance. If you don’t like 30K, how about 50K? I wouldn’t wait until 150K no matter what. But it’s your car.

Ford is banking on the fact that most new car buyers won’t keep their cars for 150K miles. The subsequent owners will pay for the lack of transmission maintenance.

You see our recommendations because of the number of problems with automatic transmissions happen to transmission that have not had fluid changes. Far fewer have had the changes.

You have a choice, but if your error and don't get that change, you save a few $$ but may end up buying a new transmission $$$$$$$$$$$$$$$

Automatic transmission failures in almost every make and model of vehicle (cars and trucks) are a fact of life. I recommend transmission fluid changes in the 30-40K range regardless of the vehicle manufacturers stated recommendations. Preventative maintenance is the key to long mechanical life so I think changing transmission fluid at the 30-40K mark is the way to go.

Those 30K recommendations come from some of the most knowledgeable and experienced members of this forum, including Transman. My basic reason for the recommendation is that automatic transmissions are expensive, and fluid changes, especially on cars with drain plugs on the transmissions, are cheap and easy to do. In my experience, the biggest benefit of changing the transmission fluid that often is that you reduce or eliminate the need for more expensive flushes, or transmission service that includes dropping the pan and replacing a good gasket.

The manufacturers are not only wrong on transmission fluid change recommendations but they’re also way wrong on quite a few other maintenance procedures.

The marketing department trumps common sense, as per the usual.

Find out how much a simple drain and refill costs.
Multiply by four.
Compare to cost of a trans rebuild.
Don’t be pound foolish.

There is very little consistency or logic to the intervals when you look between manufacturers. As an example, my Mazda recommends brake fluid changes every 24 months or 40,000 km. A Prius does not have any brake fluid change intervals recommended. Guess which one becomes more expensive to maintain when Edmunds and other sites do their analysis? Now guess how often the fluid on the Prius SHOULD be changed. I think 24 months for brake fluid is a bit aggressive. 36 or 48 should be fine. But no recommendation? Stupidity.

Ford is probably playing the same game here - get a LONG life listed for normal service to brag about low maintenance costs, but I would never, ever, ever push it that long. Given your stated driving habits, and assuming that you are accelerating nice and slowly (this makes a HUGE difference in life of an automatic), I would recommend every 36 months, regardless of mileage. That might be more than 30k, but still well short of 150k. You’ll be taking good care of your transmission, and any decent shop should do this for you for ~$120 or less… and if you do it yourself, it will likely cost not more than $40-50.

A possible counter point is the concept of Service Induced Failure. (This is not an argument against changing the fluid.) I wonder how many transmissions have been killed by mistakes made by someone at the iffy lube type places while changing the fluid?

It is cheap insurance. The thing that damages transmissions the most is heat. Its not uncommon for an engine to run 190-200 degrees or more. Since your transmission cooler runs through the radiator your transmission is subjected to these temperatures, then you add in the extra heat that torque converters put out. Your transmission can stay around 200 degrees easy. Well, ATF starts to break down slowly around 190-200 degrees and breaks down even faster the hotter it gets. 30k miles at 200+ degrees is a long time on its own, and some people dont ever change their fluid so you could imagine that their fluid is screaming to get out of there. Thats why myself and most good trans techs always recommend 25-30k services. A filter and fluid for most vehicles usually runs around $40-$50 and thats on the high side. There are those people out there that say “I dont give a $*&@ what that guy says, the owners manual says 150k and by god, I’m waiting until 150k” Well, you go for it my brother and I’ll catch you on the flip side when you are walking through my doors grumbling because you have to come out of pocket $2000, $3000, or even $4000 bucks because you wanted to be cheap. In fact, the warranty paperwork which comes with my rebuilds specifically states 25-30k or I will not honor the warranty. I’ve been building automatics for 27 years now and I can honestly tell you that 90% of my work that crosses my bench is there due to improper or lack of servicing, NOT because of manufacturer defects like a lot of people want to complain about. I’m not making any money by recommending 25-30k changes, I dont do trans services, no time, I just build them. In fact, I’m hanging myself by helping you stay out of my shop. I’ve seen many transmissions well serviced go 200k miles and more without ever being cracked open other than regular pan drops. I always say take that maintenance interval section of your owners manual and tear it out and set it near the TP roll in your bathroom just in case you run out some day. Thats all it takes, nobody can guarantee you will go 200 or 300k but your chances more than double just by simple servicing.


If you have your trans fluid changed at 30K miles by a crappy shop (or quickie lube joint) and they refill it with the wrong fluid, or “generic” fluid (which is in fact the wrong fluid) you can have “Service Induced Failure”.

Since many busy people use these facilities some would be better off doing nothing rather than have the fluid changed by a “bad” provider.

It is very important to change the fluid and every 30 to 40K is a good interval. But it is even more important that whoever does the service refill the trans with the proper fluid.

In other words, “Yes, really.”

I appreciate all the comments and suggestions. I’d like to add 3 pieces of information and get your follow-up comments.

  1. The 6F35 transmission has already been the subject of a TSB. PDF

  2. This transmission is advertised by Ford as “filled for the lifetime of the car, no service needed.”

  3. The actual fluid change procedure calls for draining and filling 3 times. It’s a 9 quart dry fill with Ford’s special ATF, even if only some of the fluid drains out each time, that’s a lot of ATF. PDF

Any further thoughts?

I wouldn’t read too much into a TSB. As far as I know, there has never been a transmission manufactured, ever, that is TSB free. A TSB does not necessarily mean the transmission is a bad one. On the contrary, the transmission could be an outstanding unit but since it’s a complex manufactured unit some hiccups will occur.

A long time friend of mine who is 55 years old runs a trans shop and started working there for his dad when he was about 12 years old. (learning a bit after school and during the summer) The guy is a transmission ace like Transman and does strictly bench work with a couple of employees doing services, minor seals, and transmission R and R work.
He would back up every single word that Transman said and has also stated that almost every transmission failure he sees is due to lack of servicing, running the fluid low due to a minor leak that is ignored or overlooked, improper servicing, or continuing to drive the vehicle for months on end with a chronic shift problem.

In all my years, I have not come across a “Lifetime” fluid. People commonly dont change their transmission fluid at all and can sometimes get 100k+ out of it. Now a days 100k is not a lot of miles. Like I said earlier, no one can guarantee your trans will last 200-300k miles but regular servicing can more than double your chances. I have seen the TSB on the 6F35. What they are doing in this TSB is reprogramming the pressure control solenoids current which will increase line pressure and cause the regulator valve to reposition itself in the valve bore. Regulator valves are very busy valves and are constantly moving in their bores. This causes the steel valves to wear the aluminum valve body, drop the line pressure and fry the clutches, (5th and 6th gears in this trans) I dont believe in lifetime fluids but I do know one thing, Ford just cares whether you make it through your warranty period. After that, they are hoping you will bring it to them for rebuilding.


I am not convinced that the current knowledge base of people has caught up to include Dexron VI for GM cars which has improved oxidation resistance, improved thermal stability and other improved characteristics and has been available since 2006.

This does not address the OP’s post but other than that, there may be some misinformation posted that does not seem to recognize the advantages Dexron VI.

By posting this, I am putting my faith in GM who has a lot to lose if this stuff does not work.

Another possible reason for early failures is that people are not interpreting the meaning of severe service correctly, are driving their cars more roughly than they will admit or are not accounting for the effects of young drivers on their cars.

…Ford just cares whether you make it through your warranty period.

Transman, don’t you think Ford wants you to buy another Ford too? I ask because Ford seems to be doing things better than it used to, so at least from my perspective, it appears as though the corporate culture may have improved.

My own take on that would be that you give people too much credit. Lots and lots of people just replace their cars on a regular basis, and the old “transmission failure” is legendary. So the Ford service guy is shrugging about the transmission saying “it just happens from normal wear and tear” while the Ford sales guy is standing in the doorway saying “psssst…let me show this new…”

Its a delicate dance to play - how long to shoot for so its not seen as “unreliable” but so that you can move a new one out the door asap. I’m not saying this is some deliberately planned thing to dupe everyone. That would be giving Ford & their engineers too much credit. But in general, I go on the assumption that all of the decisions that go into putting a car out there are based on what is “good enough” - good enough to make it past the warranty period.

Wha Who, I agree and hope GM is making strides here. On the flipside, they still insist on using Dex Cool.