Very good news, considering the alternatives.
Glad you figured that out before dropping the pan....thanks for the update!

 

Yeah, that story could have ended a lot worse.

 

I recently found out that an air shut off (a diesel engine emergency stop) can cause the same exact symptoms. The starter will start to crank the engine but act seized when the piston can't suck any air from the intake.

Thought I'd share this since I just learned it can cause a Cat 3406 generator to not want to start. (Mental note - check all of the emergency stops )