Boston Gear 55478 Oil Seal is the input oil seal designed for the XOS-18-32.75-5 family of Boston Gear speed reducers, providing a reliable seal on the input shaft to retain lubricant and exclude contaminants. It features a 1-1/8 in bore, a 2.0472 in outer diameter, and a 5/16 in width, aligning with the model’s documented dimensions. As a standard replacement part, it is intended for use in compatible speed reducers where seals have worn or failed, and is listed as 55478 by the manufacturer with availability from retailers such as Grainger, Radwell, Zoro, and Motion.
