I have the older style cast iron gear box. I noticed that stoker man posted that the oil to be used is 20 weight. I am assuming this is a gear oil but am not sure where to obtain it. Is there a substiture such as a gear oil available at the auto stores such as a 85-90 wt gear oil.
You will have a hard time finding SAE 20 machine oil in small quantities. An ISO 68 hydraulic oil or industrial gear lube would be roughly the same viscosity, but those products aren't readily available in small quantities either.
I use plain 80w-90 gear lube in the gearboxes and ratchet drives with good results...75w-90 will my next choice when my current supply is exhausted.
mozz wrote:You can buy straight 30w non detergent oil at just about any auto parts store.
Yes...but there is no real reason to use it in this application. My opinion is you would be better off with a gear lubricant, but in this case the load and temperature is so moderate that it might not matter very much. Back in the 1940's a lot of extreme-pressure rated gear lubricants were not compatible with yellow metals, but that is not the case today.