This black oxide main shaft assembly, part number 6880851, is a crucial component for any automatic transmission. It is designed specifically for Allison brand transmissions and is made with high-quality materials to ensure long-lasting performance. This main shaft assembly is perfect for those looking to replace their current transmission part or for those looking to upgrade their vehicle's transmission system. It is compatible with a variety of car and truck models and is easy to install with the right tools and expertise. Buy now and experience the superior quality and reliability of this Allison Transmission part.