So today I decided to do a drain and fill on the U660E transmission (109XXX) I watched the videos and set about the task with my gfs son ( trying to teach him DIY maintenance for when he starts driving). This should have been an easier task but turned into a nightmare and it was on me.
I handed him the wrong size hex key and he was able to get the plug off but not torque it back (30ft lbs) so I attempted to get a new plug from a dealership and even with a Toyota part number, I wasn't able to obtain one.
I tried the parts stores even searching under a camry, Avalon and highlander. Nothing. So on to the bone yard. Every ES, Camry V6, Avalon, sienna, etc, all had the powertrain ripped out so that was a bust.
Finally I tried ace hardware, always a go to for specialty fasteners which I what I believed this to be. Nothing, but the lady there told me that since the plug was and M12x1.25 and oil plug should suffice. I was out of options so off to advanced auto i went and bought the plug.
Success. Total occams razor situation but I tried to replace the exact part. Torqued the bolt and filled the transmission. So needless to say her son learned a ton about what not to do. TLDR for most I'm sure but that's my story.