Read some forum post where @wren_thomas16 nailed it, bad grounds can kill alternators quick.

Nah that old timer was full of it. 3/8ths ratchets just ain't made for that kind of torque no matter how long the pipe is. You basically made a cheater bar out of something that wasn't built for it.

Those alternators are pretty common and easy to rebuild too, so I wouldn't put too much stock in a date code on a part that's been sitting in weather. Chances are it was just good luck, not some secret trick to finding gold at the junkyard.

Last weekend I was helping a friend level his jointer at the Nashville makerspace and this guy pulls out this vintage 12 inch combination square from the 40s, all brass and rusted. He swore by it for everything, but when we actually checked it against my 4 inch machinist square the combo was off by almost a full 64th. I've been using a 6 inch Starrett combo for 5 years and never cross-checked it, now I'm paranoid every time I cut a tenon.

Whoa, that's a really good point about him missing the job. Maybe it's just me but I bet part of why he was so harsh is because he sees himself in you and it freaks him out. Like you're living the rookie dream he had to give up, and he can't handle that. So he tears you down to make himself feel better about his own choices. I mean, it's pretty sad when you think about it that way.