Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 1T553 found under Gear Subassembly Sp by Caterpillar Inc. The National Stock Number assigned to this part is 3010012373424, and the Federal Supply Class is 3010 Torque Converters And Speed Changers. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 1T553.