I just purchased a Wolverine VR-11-66 roller attachment and there is no manual available for this model. It appears to use an oil bath method of lubrication. I removed a drain plug on the drum and drained four gallons of dirty brown oil. That was way more oil than I expected and it looked like used motor oil, about 30 weight. Does anyone know the correct quantity, type, and weight for this oil. The company is zero help. Thanks in advance.