I am running a 45 horse sears engine and I noticed there is a nice sized crack in the lower unitl.... I have attempted to remove the lower unit but apparently it don't wanna come off. I am afraid to pry on the thing because the engine is 30 years old and I wanna save as much as I can without paying a high cost to get fixed. Can anyone help on how to remove this piece oh junk to make my life easier. I suppose possibly it is the drive shaft but that I have no clue how to disconnect either. As you can tell I am new. Thanks