Greetings all,

I'm in the process of converting an Archdale 18" vertical miller over to CNC. This machine sat out in a car park in the rain for a year or two before it was given to me. The transmission was full of water / oil so I striped it all down and cleaned it all up. Near as I can tell this machine dates back to the early 50's. It has a multi speed transmission that has a range of spindle speeds from 86 to 2000 RPM. My question is what weight / grade of oil should be used in the transmission of this machine.