Shit, I might've considered replacing the entire differential plate if I had that much problem removing the drain plug, but then that opens up a whole bunch of other possible variables, depending on the condition of the vehicle. Though it sounds like you might have had better luck with a new plate, as those bolts likely hadn't been touched since the car was assembled, whereas the drain plug sounds like 15 retarded monkeys took turns fucking it in the bushes.
i won't lie, every 10th unsuccessful hammer swing, i'd just look at the 6 bolts holding the plate together and think... can i?
i finished the front diff last night, took a bit of yoga, the fill plug is on the passenger side, right on top of the "axel"? i removed the wheel and turned it, and still needed to put in a 1ft socket extension, but couldn't generate enough torque, so i got underneath it and stuck my hand in there and somehow managed to break it free.
the diff drain and overfill plugs are on the bottom and the were tight. i had to use the breaker and extension and then kick off with my legs on the front wheel in order to break it. (more strength in leg squat, than arm pull), man was the plug dirty.
This impreza has the specific issue where many diy guys fuck up their front diff/cvt by using the wrong fill plug. The correct fill plug is a bitch to get to (the one i did use), while the "logical" fill plug right on top of the overfill plug actually goes to cvt.
to make myself feel better, i drained it dry, then w/o putting back the drain plug i pumped some oil into the fill plug and it dripped out right from the drain plug.
With this aside from pondering if i want to change the cvt oil at 100k, and spark plugs in the next 40k, i've done all major items on the checklist for the subaru. Same for the honda, actually ever since the ATF oil change it shifts amazing from 1st to 2nd, as in i don't feel it anymore. I'm actually wondering if and when the atf was ever changed, it wasn't "nasty" when i changed out the liquid but i can't seem to find the records for the honda really.
My next car/garage purchases will be a "creeper" and a better jack. i have this $40 trolly jack, which is "ok", but it doesn't bring up the cars super high, harbor frieght has this snap on clone that everyone seems to love.