Billy has probably already mentioned this in one of his posts, but this is NEW to me.
I was reading the instruction booklet to this Singer 404 (late 1950 - early 1960 slant needle machine) and it advised using OIL for some parts
and it said DO NOT OIL the gears - use the LUBRICANT/GREASE and this thread that I found elsewhere tells why. The oil flies off.
This is so funny - I'm so excited about having this machine working - and all it does it a straight stitch!