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Transmission Flush Myths- Busted!

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transdude

20+ Year Contributor
523
65
Jan 17, 2003
Hawthorne, New Jersey
Transmission Flush Myths- Busted!

Anyone who is even remotely involved with cars has heard this type of story- someone that they know got a transmission flush and their transmission failed within weeks or even days.

The urban legend behind this is that the "sludge" is all that was holding the transmission together and once it was removed with a flush, the transmission had no chance of surviving.

The story goes like this:
Jim was having a transmission problem, let's say that it was sluggish in the morning and would slip on take-off from a stop from time to time when it was hot out.

Now Jim has a brother-in-law named Bob that used to work on cars, do his own tune ups and oil changes, etc. When Jim mentioned the problem that he was having to Bob, his immediate response was, "You need to get that tranny flushed"

Of course Jim not really knowing anything about a car, much less an automatic transmission blindly follows the advice of his brother-in-law. After all Bob surely knows all about cars even though he hasn't worked on one for over twenty years.

Jim obediently takes his car to the local lube place for a flush and an engine oil change while it's there. Jim gets his transmission flush, pays and goes on his way.

At first, he notices maybe a slight improvement in performance but his transmission is still exhibiting most of the original symptoms.

About two weeks later Jim is driving to work and he stops to pay a toll. When he tries to pull away from the toll booth the unthinkable happens- the car just revs and goes nowhere, as if it is in neutral. Jim moves the shifter into low and is able to limp his car off to the side of the road and wait for a tow truck to take him to a transmission shop.

What happened?

Here's a list of reasons why the transmission flush myth exists:

•The myth is propagated by people who claim to be experts. I have even heard of transmission repair shops who contribute to the myth in the hopes of scaring potential customers into having their transmission overhauled rather than maintaining it.

•There are thousands of "internet experts" who promote the misinformation- it's truly a case of "monkey see, monkey do" on steroids!


•There may have been a time in the early days of automatic transmissions when failure after a flush was more common, perhaps because of antiquated friction material and transmission fluid technology during the 1950's and 60's but this was before my time so I'm not able to truly discuss the legitimacy of the possibility. I can, however, say with certainty that it's not an issue with 99.9% of the vehicles in service today. If your owner's manual is in the glove box and not painted on the wall of a cave, you are probably good to go.

•"Sludge" is all that was holding the transmission together and when it gets cleaned out the trans in going to fail immediately. Guess what? If you have sludge in your transmission, it's already bad and in need of a repair.

•Once in a while a flush is performed, usually at a quick lube operation, and the transmission is not refilled correctly- resulting in failure soon thereafter. Of course the incorrect fluid level is not recognized as the culprit- the transmission flush is! Many automatic transmissions have fairly complicated fluid level checking and filling procedures that are best left to a transmission repair expert to perform.

•People have unrealistic expectations. A transmission flush is no more likely to fix a failing transmission than an engine oil change is to fix a major internal engine problem. Both of these things are great to do regularly but they are maintenance- not a fix for a problem.

•The reality is that most people don't think about their transmissions until the day that they have a problem. Jim's transmission was on borrowed time- it was going to fail anyway but now that it has, he is going to perpetuate the myth. If he ever hears someone mention a transmission flush, he's going to proclaim, "I had that done and my transmission blew up within a month!"

I have been in the transmission repair industry since 1987 and can honestly say that I can't recall a single time where I saw a healthy transmission get a flush or a fluid change and subsequently have a problem. A transmission flush is the best maintenance that one can do to extend the life of your automatic transmission, don't miss out on the benefits because of the nonsense that exists surrounding changing your transmission fluid!

Anyone can feel free to repost this as long as you leave the "about the author" part intact.

About the author:
John Lombardo is co-owner of <a href="http://www.importperformancetrans.com">IPT Performance Transmissions</a> and has been in the high performance industry for over 20 years.

<a href="http://www.importperformancetrans.com/"> IPT Performance Transmissions</a> <br>
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Definatly all true...as are alot of myths that float around. He said she said!

Good info John....I got my Trans temp gauge, and the Lubegard Thanks!
 
I have been in the transmission repair industry since 1987 and can honestly say that I can’t recall a single time where I saw a healthy transmission get a flush or a fluid change and subsequently have a problem.

At about 120,000 miles I had the Talon’s ATF flushed and replaced for the third time and shortly afterward it developed a torque converter shudder. Replacing the generic ATF used by the shop with ATF+4 fixed the problem. As John said the problem was the incorrect fluid not the flush.

That same shop believed in the myth. I heard the manager decline to flush an automatic transmission because it had high mileage and had never been flushed. They weren’t fishing for a rebuild because they didn’t offer that. I don’t use that shop any more.

By the way the IPT rebuild in the stroked Talon along with the billet high stall torque converter makes the Talon a joy to drive.
 
I worked at a lube shop and if a customer wanted a flush and their car had over 75k they would have to sign a paper saying they won't sue if the transmission fails.
 
At about 120,000 miles I had the Talon’s ATF flushed and replaced for the third time and shortly afterward it developed a torque converter shudder. Replacing the generic ATF used by the shop with ATF+4 fixed the problem. As John said the problem was the incorrect fluid not the flush.

That same shop believed in the myth. I heard the manager decline to flush an automatic transmission because it had high mileage and had never been flushed. They weren’t fishing for a rebuild because they didn’t offer that. I don’t use that shop any more.

By the way the IPT rebuild in the stroked Talon along with the billet high stall torque converter makes the Talon a joy to drive.

I think most of the time shops refuse to do it because they end up getting into a legal battle over them messing up someones transmissions if it fails shortly after they change the fluid. Most drivers just drive there cars, and dont notice small issues that accure, then they get something fixed and the person who touched it takes the blame.
 
I work in medical research and see this same phenomenon in health - in fact, I'd say 90% of all health myths are the result of correlation without causation. An older person takes some medication for the first time and has a heart attack a week later. Did the medication cause the heart attack? He'd probably say so, but millions of people have heart attacks who didn't take that medication and millions of people who take that medication have never had a heart attack. Heart attacks aren't usually "caused" by something the person did a week earlier - they are caused by a lifetime of poor health and/or bad genetics.

Remember when cell phones first became popular and some guy came forward with a "cell phone shaped" brain tumor that his cell phone supposedly caused? The reality is that brain tumors can take on all kinds of shapes and lots of people got them before we had cell phones. Brain cancer rates haven't changed now that everyone uses cell phones, but I remember MOST people I talked to at that time being convinced that cell phones caused brain cancer based on that one person's coincidence (and of course, he filed a huge lawsuit).

Remember when silicone breast implants were causing all these health problems and lawsuits ran Dow Corning out of business in the early 90s and silicone breast implants were pulled off the market by the FDA? They are back on the market because further research showed that in fact they are pretty safe and the people who claimed damages were either lying or had problems unrelated to the implants (ie, at the time, any health problems a person with implants had was automatically assigned to the implants, as if only implants caused health problems and everyone who didn't have implants were in perfect health as a result).

I think I could go on and on. Transmission flushing causing transmission failure sounds a lot like these examples.
 
At about 120,000 miles I had the Talon’s ATF flushed and replaced for the third time and shortly afterward it developed a torque converter shudder. Replacing the generic ATF used by the shop with ATF+4 fixed the problem. As John said the problem was the incorrect fluid not the flush.

That same shop believed in the myth. I heard the manager decline to flush an automatic transmission because it had high mileage and had never been flushed. They weren’t fishing for a rebuild because they didn’t offer that. I don’t use that shop any more.

By the way the IPT rebuild in the stroked Talon along with the billet high stall torque converter makes the Talon a joy to drive.

This is an excellent point that I forgot to include. I certainly have seen vehicles that were flushed and filled with an incorrect fluid type have issues. Thanks.
(This may be why I'm a transmission mechanic and not a writer).

-John
 
Here's my take on it after going to a franchised national tranny shop for a pan gasket change. In my case they leave out 2 to 3 qts of fluid even though 2 guys fill and check on flat ground with engine running and car in neutral like the way they're supposed to on dsm's and even check it several times with me watching. I drve away and tranny starts shifting eratically jumping from gear to gear. Pull over to find dipstick is bone dry. Drive real slow 4 blocks back to the shop where the guy says maybe you have a bad tranny. I tell him about the low fluid and owner says I think your dipstick is the wrong size for your car. His worker looks a him increduously and saunters over wth a gallon jug of fluid and proceeds to add about 3 qts to fill to proper level. I drive off and have no further problems.

So my take on it is with tranny shops offering cheap flushes is to drum up rebuild business and I even have an idependent shop near me advertizing tranny tune-ups for $9.95 :D IMHO never go to a tranny shop for a fluid + filter change UNLESS you're 100% sure they're honest or you're probably going to get talked into a rebuild. Better to do it yourself or have a mechanic who doesn't do tranny rebuilds do it because he has no interest in trying to stick you with one. Tranny's rebuilds are one of the few repairs that you really can't even tell if they actually did ANY work to it internally and I'm sure there's many times people go into shops with bad tcu's and get stuck paying for complete rebuilds.
 
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I used to take the car to Jiffy lube for a tranny fluid + flter change (no flush) until 1 day the guy leaves off 1 pan bolt and I drive away with fluid leaking out. I go back and he could care less saying he misplaced 1 bolt so he decided to leave it off :mad:
After that I always did filter + fluid changes myself and never had a problem.

Like I said in my other post best to do it yourself, stay away from tranny shops for flushes and yes I know the tv + radio ads look and sound real promising but don't fall for that. Stay away from tranny rebuiders unless you know you need a rebuild and for a flush effect in my driveway I used to change fluid + filter, drive car 15-20 min, drain fluid + replace with more brand new fluid and PERHAPS even repeat a 3rd time so as to get a good flush effect.

Aside from not making sense to go to a rebuilder for a flush imo it doen't make sense having a low level tech at pep boys, sear's auto etc mess around with flush machines on your tranny because do you really want a non expert messing around eith your tranny?

All around best to change filter + fluid yourself :thumb:
 
Good info as I am having trouble with my transmission at the moment. I'll look into this.... Thanks!!!!
 
I'll add a little more in that a national tranny shop did get me on a rebuild on my dsm 8 yrs ago selling me on their 'iron clad' warentee but when I had trouble the warrentee didn't help much. They even messed with the valve body making the shifts on my tsi much slower and softer telling me that's what they generally do and refused to set it at factory specs. In nearly 14 yrs of owning 1g's going to a franchised tranny shop is BY FAR the worst mistake I've made and that's saying a lot because early on I went to mitsu dealers to drain my bank account and be stuck with halfass work.

Definately do some research on shops before taking the dsm for internal tranny work whether A/T or M/T :thumb:
 
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