Brand , unused Driver Kit / Primary Pulley designed for reliable performance and long service life. This replacement part is engineered to match or exceed the specifications of the original component, ensuring a precise fit and smooth operation. Key Features: quality replacement for General Transmission RT400 Driver Kit / Primary Pulley Direct replacement for original part number MIA13031 Compatible with RT400 Transmission models including AUC11077 (substitutes for AUC10266, MIA13114, MIA12863, or MIA12656) Fits John Deere D105 and other compatible models Built for durability to handle regular use in demanding mowing conditions Easy to install with standard tools for minimal downtime Benefits: Restores smooth transmission function for consistent mower performance Helps prevent costly downtime caused by worn or failed pulley components Maintains proper belt alignment to reduce wear on related parts Reliable fit ensures compatibility without modification Applications: 1. Replacing a worn or damaged primary pulley that causes belt slippage or irregular transmission operation in your D105 or other RT400equipped mower. 2. Restoring drive performance after seasonal maintenance or major . 3. Keeping a spare pulley on hand to minimize disruption to mowing schedules during peak grass growth periods. Specifications: Part type: Driver Kit / Primary Pulley For use with: General Transmission RT400 units OEM Replacement Part Number: MIA13031 Compatible Transmission Models: AUC11077, AUC10266, MIA13114, MIA12863, MIA12656 Compatible Equipment: John Deere D105 and other models using the RT400 transmission This fit replacement is the ideal solution for ensuring your RT400 transmission operates smoothly, delivering efficient power transfer for consistent mowing results.