The John Deere GXH43348 Blade Shaft Spring is an authentic OEM replacement part designed for various John Deere 100 Series lawn tractors. This spring plays a crucial role in the mower deck assembly, providing the necessary tension for the blade shaft mechanism, which is essential for proper blade engagement and consistent cutting performance. Manufactured to John Deere's specifications, it ensures durability and a precise fit for models such as the 102, 105, 115, 125, 135, 145, 155C, 190C, and D100.