With Bank Line in the 70s we were issued with Crankcase/tank inspection suits, a bit like a moving Turkish bath in a hot crankcase, most people didn't wear them, just get oily! I always kept the lub oil clean though, that,s what purifiers are for!!
I often used to find nuts a bit slack, but whilst with port line I did find a centre top end bearing squeezing out (quite regular on some of the John Brown LB Doxfords). Main problem was getting the spare off the ships side, been there I think since 1936!!