HELP: Drained trans fluid instead of motor oil and got some oil into the ATF.

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I tried changing the oil on my subaru 2007 forester (100, 000 miles) and stupidly drained the tranny fluid instead. Geeze it even uses the same filter...

so I tried driving it (50 ft) and of course no shifting...i figure it pretty fast and poured the drained tranny fluid and transmission filter back into the car...but heres my dilemma....the tranny filter is the same size as the oil filter....ugh....

i put in about 3 tablespoons of motor oil into that filter and then screwed it into the tranny filter spot...

I'm going to drain the ATF fluid asap but you can just replace about a gallon at time unless flushing.

will that 3 tblspoons of oil contaminate the tranny fluid ((about 2.5 gall) to the point of damaging the tranny/engine?

thanks for any advice.
 
Obviously I would change the filter and fluid. Other than that you should be fine. More damage was done without the fluid than with miniscule amounts of motor oil. Don't sweat the small stuff.
 
I don't think the 3 oz. has hurt your transmission but I would change it now that I know what goes where just to be safe. Other members will be able to tell you for sure. Before you change the oil again, try to find a service manual and/or videos that go with your vehicle. This will help you prevent this type of mistake, which anyone could make without guidance. I prayed for you. I'm sure most of us have been in similar situations. You may make other mistakes but you'll get this right from now on.
 
There is a story about a shop, Walmart? that drained the transmission fluid, not the engine oil, filled the engine with oil which made it waaaaaay overfilled and both the transmission and engine died.
 
tranny fluid is essentially thinner oil with different additives, but the CVT is another sad story
 
What surprises me most is that a company would actually put a spin on transmission filter in a consumer vehicle! Wow! Wish I had one of those..
 
Originally Posted by skyactiv
There is a story about a shop, Walmart? that drained the transmission fluid, not the engine oil, filled the engine with oil which made it waaaaaay overfilled and both the transmission and engine died.



My daughter's boyfriend has a Subaru and Pep-Boys did the same thing. Drained his ATF and filled the crankcase. His car died a close to home. My daughter was on the phone. She had PepBoys jacking the car up in the middle of the street at 10pm to replace the fluids. That was a couple years ago and the car is running fine.
 
Start over. Get the proper Subaru transmission filter and fluid, and add the exact amount of fluid you drained originally. Those AT transmission filters allegedly are lifetime filters but aren't made to be removed and installed again..
 
thanks again for the info. very helpful.

btw - is it ok to mix in full synthetic ATF with the existing non-synth ATF?
 
Last edited:
Originally Posted by kschachn
Joseph is that you?

lol.gif
 
Originally Posted by pointbob
btw - is it ok to mix in full synthetic ATF with the existing non-synth ATF?


Yes
 
Reminds me when I did an oil change and got the front and back mixed up and changed the differential instead.
 
Originally Posted by kschachn
Joseph is that you?


No...there would be a bunch of personal drama to go along with the car problem!
smile.gif
 
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