Description:Gear part # 378-9530 provides a sun gear for the swing drive system.All Cat gears have unique metallurgy compositions tailored to specific applications, with special steel formulas that improve impact resistance and ensure uniformity and proper load transfer. Some Cat gears also undergo proprietary heat treat processes to improve surface, bore, and core hardness. The result is greater durability, which means longer life and better performance.Attributes:• Hardened steel sun gear• Spur Gear Number of Teeth: 17• Inside Diameter: 50 mm (1.97 in)• Outside Diameter: 116.82 mm (4.60 in)• Width: 120 mm (4.72 in)Application:Consult your owner's manual or contact your local Cat Dealer for more information.