Not a chance. Those forces are pretty small. It is from somebody beating on it with a hammer, or some similar trauma. FYI the oil mpump load is vastly larger than any vacuum pump load.
A hammer - that would splain it
The only way the vac pump could create that much resistance is if it broke a vane which jammed against something (I don't know what).
FWIW, when the pump picked up the oil it slowed the drill significantly - I was a bit surprised at how much load there was. I did have the IM shaft in but as you stated theman53, it wasn't spinning cause the vac pump was out. My point was that the resistance felt would be the only significant force to generate thrust in the flange. My vac pump spins with very little effort.
Hopefully ein bora will get a buyer soon as we are lighting up his post daily.
It is interesting though.
what I was referring to is that if the guy was spinning the oil pump with a drill then the IM shaft was not in there. If it wasn't there then the gear wouldn't be sending it to the thrust surface. Now if he drove the oil pump with the IM shaft installed and somehow held it all in place then that is different.
FWIW I think some break from someone prying on the pulley to get the pulley off. I have only had one that was broken, but the IM pulley was eaten up by a screwdriver, so that is where I get my theory.
I agree with your theory.
Hard to get to the opposite end with a hammer.