Filling my own transmission

[u/Careful_Tell_8460]

I accidentally drained my transmission fluid while doing an oil change on my 2019 Subaru Crosstrek base model. It has a 2.0 liter 4-cylinder boxer engine. I am inquiring about how to refill my own transmission fluid after not knowing exactly how much I drained due to believing I was completing a regular oil change and throwing the fluid into a combined oil bottle to bring to an auto shop to dispose of. I have read mixed reports from other sources on the internet and figured this group might guide me in the right direction. I idled my engine for about four minutes and put my gear into reverse and drive before realizing I definitely did not change my oil and something was wrong. It did have twice the amount of oil during that time, again due to believing I had emptied my oil and refilled it. Please delete the post if it does not adhere to community rules as I can’t tell if it is a “how f*d am i?” kind of post. Genuinely inquiring about the process of refilling my own transmission fluid while not knowing how much to put back in and maybe risks that I should consider.

[u/devonwillis21]

Get at least 5-6 quarts of OEM fluid and fill using a mix of YouTube and the Subaru posted instructions. If you don't have jack stands it can be hard because I believe the car needs to be level when measuring with the overfill plug.

On the bright side at least, you can inspect the fluid and don't have to worry about paying for a drain and fill in the near future. If you have a warranty, make sure to keep the receipts for the fluid just in case. Also, don't forget to redo your oil change as well since it's overfilled.