The most reasonably priced component used on the Gs500eu 1989 (k) Germany (e22) Oil Filter-oil Pump is the Stud 6x20.
With a quantity of twelve pieces, the Bolt is the most used part in the OIL FILTER-OIL PUMP diagram.
Some items from this specific schematic: Nut, Cap,oil Filter, Nut 6mm, Regulator Assembly,engine.