Questions and tip: Replaced my transmission/transaxle fluid

Long story short, I traded in my 2012 Hyundai Veloster for a high milage (107,000 miles) 2010 Toyota Prius II. Everything on the car seems to be in phenomenal condition. I read on the forum that it maybe a good idea to change fluids after 100k (even if Toyota is ambiguous about it). One dealer, who shall not be named, said you NEVER have to replace it and charged $300-400 saying that some fancy laptop need to be connected etc. Another dealer recommended me to just change it since the transmission is the lifeline of this car and quoted me $150. Perhaps it was an overkill but this is my first used car so I decided just to get it over with so that im set for another 100k

Anyways, I decided to buy 4 quarts of Toyota ATF WS fluid, 10mm hex socket, fluid pump, and do it myself. Took me like an hour just to figure out where the drain and fill plugs were. lol

Anyways, I have questions:

Question 1) I tried to maintain the car on 4 jacks so that it is as level as I could make it. Drained about 3.0-3.25'ish quarts of transaxle fluid. The video will show why I couldn't keep track. I pumped about 3.5 quarts till it started leaking out. Left me with 1/2 of a quart. I may had plugged up the fill plug as fast as I could, Steady slow leak. Is there any harm with slightly over filling the transaxle case? I doubt it was grossly overfilled because the number seem to add up, 3.5 quarts in 3.0-3.5'ish quarts out, but I was reading that fill levels could impact the vehicle. The design seems to prevent you from over filling with a side fill plug. But I assume if I did overfill it would be by few millimeters.

Question 2) Is it normal to have a little less than 1/2 quart left over in the last quart? The capacity is 4 quarts but I assume maybe 1/2 quart of the old stuff is kept in the transaxle case. The write ups I saw see people with 1/4 quart left.

Maybe i'm over reacting since this is my first time changing transmission fluid, i've never driven or kept a car over 100k.

Thanks for an awesome community! Prius Chat really helped me with the decision to trade my car in for an older Prius.

Tip: When removing the drain plug, put pressure on the plug...its that last thread when things gush out. Bigger pan wouldn't hurt either

 

lol, wish I figured that one out earlier. Oil plugs no problem, but this was like one thread and it was like Mt. Gushmore! I tried turning it as gingerly as I can.

 

Nothing was wrong except it was in an accident where I got rear ended and sustained structural damage. Although the repair shop did it super impressive job, I just never looked at her the same after that. Plus, although there were a ton of cool standard features, it wasn't really practical for my lifestyle. I like road trips, drive a lot, and pretty active outdoors. Also, I didn't feel confident driving the car over 100K (assuming I decided to keep the car). Toyotas and Hondas were and still are the most reliable cars I've ever driven. Minor things started to break on the Hyundai. This Prius has over 100K and it still drives like a new car...i'm impressed.

A cool car if I was a teenager and still a cool car. its just my needs have changed. I do miss the handling. I've always driven sporty econoboxes, Civic Si, Mazdaspeed Protege, and Veloster. The prius isn't really that sporty to toss around.

 

BTW, turns out I was 1/2 quart too low. Maybe I wasn't as level as I should have been. Its cool, dealer only charged me $50 to check and top it off. Still lot cheaper then getting it done at the dealer and the satisfaction of doing it myself. They also clarified that over filling it by a bit doesn't matter, under filling can be an issue.

 

Thanks! I had no clue until now!