I have the same oil filter on york y53 ammonia compressors, on the compressor you unbolt the filter and take it out, there's a reservoir under it where all the crud collects,I bend a spoon at 90° to scoop it out./////////////thanks DD.
The DSG's have oil level and oil flow sight glasses on the headstock and the threading gearbox, later ones have a sight glass on the apron as they have a pump in there as well. Late 60's and on have a pressure switch in the headstock that illuminates a red light on the switch panel if there is low oil pressure. Biggest issue is if you don't use the machine for an extended length of time the pumps lose their prime and you have to remove the headstock cover to reprime it.
