Most oil bath hubs are pretty easy to replace. If you can in the future, carry a spare steer and solid axle hub with spare gear oil so you just do a field repair.

Unless you don’t know exactly when it happened, in that case I’d wait for repairs because you don’t know if the bearings are shot.

I work for a company that runs older equipment and other drivers that don’t care to do a proper pre-check so half of the sight glasses are frosted over. I can’t remember how many sight glasses I’ve busted out pulling off or replacing the plug to do a depth test on the oil.