If you change the oil in the front axle of these tractors you drain it from the lower spindle. When you refill it you put the oil in the center axle housing until it comes out the level plug. If you then walk away happy the oil level will be too low!!! It takes a long time ( like hrs?) for the oil to work through the bearings into the final drive hubs. There are plugs near the top that you remove to let the air out/ set level. be sure to recheck level to be sure it is full. I have a method in the shop to inject the oil in the drain plugs until it comes out the level plugs, makes it real fast for me but not many can do that.
Ed
Ed