Is 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.
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.
Mark V completely upgraded to Mark 7
Mark V 520
All SPT's & 2 Power Stations
Model 10ER S/N R64000 first one I restored on bench w/ metal ends & retractable casters. Has Speed Changer, Model 4E Jointer, Jig Saw with lamp, a complete set of original accessories & much more.
Model 10E S/N 1077 oldest one I have restored. On bench w/ metal ends & retractable casters.