Trans. Oil in bellhousing

I have a Hough 65C front end loader with a DT407 engine. Yesterday when i tried to start it the starter did nothing.

I pulled the rear cover off of the starter and oil ran out of it. One of the brushes was broken and the rest of them were a mess.

I removed the starter and can see where there is oil in the bell housing. Is this supposed to be normal or do I have a bad seal somewhere?

Buying a new starter but what about the oil?

Thanks for the help.

Trans. Oil in bellhousing