Transmission Fluid Way Overfilled?

All righty I really wanna try and put my super anxious mind at ease...

Previously over the last five years, my roommate and I only took our Priuses to one specific shop. When I shared our experiences with the shop here and folks expressed concerns, I took a step back and reviewed my records. We no longer go to that shop.

According to the shop's records and mine, they were the last ones to service the transmission fluid on my 2010. My anxiety pushed me to double check all of thier work. I documented that process over in this thread, where we discuss how it was overfilled.

I did my roommate's 2017 the other night, and I'm even more perplexed. Same shop, also very overfilled.

Now comes my usual brand of Overexplaining™, but please bear with me.

• I drove the car around the block to bring it to temperature, planning that it would cool down to workable temperatures while putting it on jack stands and staging the area.

• I placed the fob into a Faraday cage (aka a metal pokemon card tin).

• I put the car up on four jack stands.

• I used 3 levels: one on each door sill, and one level in the center of the roof between the driver passenger seats.

• All indicated the car was level.

• When I cracked the top/fill plug, fluid immediately tried to pour out. When I opened the drain plug more than 4 quarts of fluid came out.

• What I don't understand is why I was unable to get more than three quarts back in without it overflowing.

• I asked him to help me check, recheck, and triple check the vehicle was level. Hell, I even deliberately jacked one side up higher, and the levels reflected the change appropriately.

• I turned the car on and it sounded okay, so I drove it around the block. No idea if it's just confirmation bias, but it did feel like it's driven smoother than in recent memory.

My roommate has been driving it and says everything seems fine, but my nuerodivergent brain doesn't like all the unanswered questions. >_<

I mean, my first thought was that the odds of the shop screwing up twice and overfilling them both should be minute. But I can't argue with the fact that I had all of that fluid measured out and physically in front of my human eyes.

I can't just conjure transmission fluid out of nowhere (although admittedly that would be very convenient), so logically, they had to have somehow overfilled them both. I just for the life of me cannot figure out how that's possible when I couldn't even get three quarts back in??

I hate fussing with the shields, but I don't want to blow up his transmission either. Is it just my anxiety, or is it realistically worth an actual recheck?

 

You know what, I wouldn't be surprised if they filled it through there if such a thing is similar on the '10 and '17.