chapmanruss wroteIs it leaking oil from the cover plate gasket or from the bottom of the housing? As JPG said oil leaking is a common problem. Most of the Jig Saw replacements are no longer available from Shopsmith. If you need to make a new gasket follow the pattern of the old one. It is important to have a cutout for the vent hole in the upper side of the housing. See the arrows in the gasket picture below.
$matches[2]No mater which way you place an original gasket there is a cutout for the vent hole. The vent hole is indicated by the arrows in the picture below.
10-54 Back Cover c.jpg
ALL 8 cutouts are required in order to make orientation decision irrelevant.
However only one cutout is necessary if gasket is orientated correctly.
The vent hole in the side is what gets plugged up(teeney tiney). See RED arrows above.