I'm in the final stages of putting back together my Clausing Colchester 13" machine. I've cleaned off 30 years worth of overall use and abuse.
This machine has an oil tank holding about 2.5 gallons of spindle lube underneath the headstock. A pump driven by the main drive motor distrubutes oil to the spindle bearings as well as dumping oil on the forward and reverse wet clutch and splash lubing the rest of the gears. When I first opened up the headstock, everything was coated with a fine black grime. My best guess is that this was clutch material resulting in normal wear from years of use. Since the machine has an oil pump, placing a filter on the output of the pump seems like a good idea on keeping harmful particulates out of the headstock.
Any ideas on what might work. Micron size rating that would filter abrasion from clutch use. The finer the filter the better but the tradeoff is greater restriction resulting in lower flow rate. The pump is a centrifugal impeller style putting out maybe 5 to 10 gpm with fairly low working pressure as a best guess. I don't want to kill my machine by cutting off the oil supply but I would also like to keep the oil as clean as possible.
Any experience in this arena is greatly appreciated.