Dear Bicycle Mechanics Everywhere,
I don’t really blame you, it was those who went before you and were given the responsibility to teach you that are to blame. Yes, I realize that most bottom brackets today are pressed directly/indirectly into the frame. This makes your job easier in that it doesn’t matter what side of the frame the bearing goes into because they are the same. However, as a professional technician you should assume the responsibility of continuing your training and ensuring that if something is over your head you ask.
The first thing that you should have been taught about bottom brackets (at least on those old threaded ones) is that if it doesn’t go in by hand, something is wrong. If something is wrong and you can’t diagnose it, you should get help from someone else. Otherwise this happens,
As strange as it may seem, if it isn’t going in by hand it probably means you’ve got it cross threaded. But who am I to tell you what to do? All just remain as a lowly bike wrench and continue to fix your screw ups.
That is all.
Sincerely,
Moose K Nuckler