My Mazda b2000 distributor seized up and snapped its drive shaft. It had to have seized up at the bushing because the cam and distributor gear were unphased. Had a friend with a Honda one of and his camshafts seized and snapped in half right at a bearing journal. I'm not even sure there was a bearing insert. Lots of torque on those parts being driven by the timing chain or belt or helical drive.
