Some background to the question in the title:
Recently after some inspiration from the forum I modified the feedshaft clutch and turned town it's OD so that I could get more travel towards the chuck. Some days later I made a silly mistake and crashed the carriage into the chuck, in the process I stripped a couple of gears in the gearbox and twisted a shaft. This should have not happened had the feed shaft clutch worked, alas it did not! And guess whose fault was it? All mine, when I assembled it after I had it modified I failed to adjust it properly 
I have now replaced the broken parts cleaned everything and put everything back. While at it I took the apron apart and cleaned the apron gearbox as well, the oil inside was more like treacle both 8n colour and consistency. I filled both gearboxes with Tellus 68 oil up to the sight glass, however I think this is low. Not sure if the gears touch the oil at all.