[need4speed]

Its not really a big deal as long as you maintain your fliud level but it is a bit messy and an annoyance. With only 300 miles I think you would be happier if you get it taken care of.

If your yoke is not new it may be slightly worn at the point where it contacts the seal allowing a little so seep out. To fix it you would have to replace your yoke.

If you have a dial indicator you can also measure the play between your tailshaft bushing and the yoke, there is a specific specification that this play must meet or it will also cause some leaking from vibration and may have caused the crack in your seal.