Do transmissions "self heal"?

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281
Location
Illinois
I put a post up last week about an oil change shop putting the incorrect transmission fluid in my Sebring. With the SPIII universal fluid they put into it, the gear changes were abrupt and the car engaged into gear very hard. Now that the correct ATF+4 fluid is back in place, the shift quality and gear engagement has been constantly improving and now the transmission is shifting extremely smooth and gear selection is quick with no jerking. Would an Automatic transmission self heal itself? The car went from feeling like the transmission was on its last leg to feeling like a brand new car.
 
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ME
^ yeah dodges have an adaptive parameter that feeds back on itself. In fact you can scan a prospective used car to make sure the adaptives are within the normal range and it's not compensating for wear or wrong fluid.
 
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Southeast Texas
As hard as it might be, try your best to just forget about the issue (not that we mind your questions - glad you posted). Stressing won't help a thing. Besides you may very well luck out and there be no effect on the lifespan of the trans. For all we like to complain about cars and their headaches, they are tougher than we give them credit for. I would think even the wrong fluid can't do much if any harm in such a short period of time.
 
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Oregon coast
Originally Posted By: carguy996
I put a post up last week about an oil change shop putting the incorrect transmission fluid in my Sebring. With the SPIII universal fluid they put into it, the gear changes were abrupt and the car engaged into gear very hard. Now that the correct ATF+4 fluid is back in place, the shift quality and gear engagement has been constantly improving and now the transmission is shifting extremely smooth and gear selection is quick with no jerking. Would an Automatic transmission self heal itself? The car went from feeling like the transmission was on its last leg to feeling like a brand new car.
Do you sober up if you stop drinking beer and whiskey, and start drinking water and coffee? Your trans had the wrong fluid and now has the right fluid.
Quote:
Would an Automatic transmission self heal itself?
NO, but a person putting proper fluid in will.
 

MolaKule

Staff member
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Iowegia - USA
Originally Posted By: carguy996
...Would an Automatic transmission self heal itself? The car went from feeling like the transmission was on its last leg to feeling like a brand new car...
An AT will not self heal itself. What happened is the prior fluid didn't have the the right friction characteristics or the correct Brookfield viscosity. The fluid they put in their was definitely not a universal fluid, no matter what they told you. Hopefully, the shop did a complete fluid exchange.
 
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Montreal, QC, Canada
Transmissions do "heal" and adjust, based on wear. So if you had poor shifting from incorrect fluid, then put in the correct fluid, the transmission will "re-learn" proper band pressure to apply to give the desired shifting. But actual mechanical damage, such as clutch packs glue dissolving, can't be "healed". You'll just have to let it "re-learn" and hope the wrong fluid didn't grenade the trans.
 

MolaKule

Staff member
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Iowegia - USA
Edit timeout. Here is the complete post.
Originally Posted By: carguy996
...Would an Automatic transmission self heal itself? The car went from feeling like the transmission was on its last leg to feeling like a brand new car...
An AT will not self heal itself, relearn, yes. What happened is the prior fluid didn't have the the right friction characteristics or the correct Brookfield viscosity. The fluid they put in there was definitely not a universal fluid, no matter what they told you. I find most of the commercial Universal PI (additive) packages, if used with the correct base oils and VIIs, work very well over a wide range of transmission types. I have also found that some transmission shops in my area are using some off-brand fluids in which they have been told by the manf. that the fluid is of universal use. I have been trying to educate them on which fluids will work properly and which fluids will not. Ask what brand of fluid they are using and if in doubt of their 'bulk' fluids, insist on a licensed fluid. Hopefully, the shop did a complete fluid exchange.
 
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The original Chrysler Ultra Drive transmission....the worlds first fully electronic,self adaptive transmission.(cost cutting and incorrect fluids really hurt its longevity for a decade after its debut).
 
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Central NY
Aren't those the same transmissions that were used in Hyundais and Mitsubishis? I had a friend with a Hyundai that had it and it surged real bad (or just didn't shift) from 2-3. One day, it decided to stop shifting into 3rd alltogether and it was stuck in a parking lot. I bought 3 quarts ATF+3 or +4 , can't remember, sucked the motor-oil-colored transmission fluid out therough the dip stick and put in 3 quarts of the Chrysler fluid. It had a harsh 2-3 shift after that, but it did actually shift into 3rd! The 3-2 shift would occasionally bark the tires. 150K on a weak transmission and original fluid. Can't complain!
 
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Location
Indiana
When the ATF+4 was added, was it a flush or a drain and fill? If it was just a drain and fill, there is still a bit of the wrong fluid in there. Might not hurt to do a few more drain and fills in the near future.
 
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Cape Cod, MA
Originally Posted By: dlundblad
If it was just a drain and fill, there is still a bit of the wrong fluid in there. Might not hurt to do a few more drain and fills in the near future.
Agreed. If a D&F, there might be just enough correct fluid to allow the transmission's adaptive programming to barely compensate, and as the fluid ages, it may start to go south again. Get a complete exchange done...better to be safe and possibly waste a little fluid than to have to go through your stress all over again.
 
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NY
Originally Posted By: RF Overlord
Originally Posted By: dlundblad
If it was just a drain and fill, there is still a bit of the wrong fluid in there. Might not hurt to do a few more drain and fills in the near future.
Agreed. If a D&F, there might be just enough correct fluid to allow the transmission's adaptive programming to barely compensate, and as the fluid ages, it may start to go south again. Get a complete exchange done...better to be safe and possibly waste a little fluid than to have to go through your stress all over again.
Exactly. At this point you have no idea what the % is of the wrong fluid that is in the unit.
 

carguy996

Thread starter
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281
Location
Illinois
It was a full flush, the shop did 2 flushes with the ATF+4, they evacuated the "universal" and put in +4 and then did another flush removing the +4 and then did a final fill with +4.
 
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FL
Originally Posted By: carguy996
It was a full flush, the shop did 2 flushes with the ATF+4, they evacuated the "universal" and put in +4 and then did another flush removing the +4 and then did a final fill with +4.
Did the shop that made the mistake fix it? Just curious. Never mind...I just read your other post.
 
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1,909
Location
Tracy, CA
I don't think AT's "heal" themselves. In the OP's case, I would think that the correct fluid would eventually displace and replace the incorrect fluid that's saturated the friction materials in the clutches and bands. The gradual improvement in shift feel would give the impression that the trans healed itself. shrug
 
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