Need more info! What equipment is this on? What environment is the equipment in?
Pardon if you know this already, (and I'm not an expert on oil), but its a multigrade gear lube usually required for equipment used in areas with high temperature extremes. When its cold it behaves like an 80 weight oil, when its hot it behaves like a 110 weight oil. This gives better protection at temperature extremes. In the old days before they invented multigrade oil, you had to change oil in your car with the seasons. A 40 weight oil was thick and made it hard to get the engine started when its cold, so in the winter you'd use a 10 weight oil. But in the summer, the 10 weight oil thinned out like water and the engine would wear a lot faster so you had to use 40 weight in the summer.
Enough history... thus my question what kind of equipment? If you don't have the temperature extremes, then there should be no problem running a single grade oil.
However, there's other factors to consider as well - i.e. most oils have various chemical additives for certain applications. i.e. engine oil often has detergents that help trap combustion by-products. Gear oil usually doesn't have detergents.
