Ariens 52419400 – Replacement MPN: 52419400 GEAR CASE- ALUM-LARGE 28 Genuine Ariens Part # 52419400. Ariens 52419400 Gravely Gear Case Alum Large 28. Ariens Part Number: 52419400 Ariens. GEAR CASE- ALUM-LARGE 28. Genuine Ariens Part # 52419400. We are proud to be a factory authorized retailer. We use several different carriers and choose the most economical for the item and destination based on the estimated transit time displayed. FixMyToys – A Division of Ball Equipment.