100Y1 (RD20317 Main Gear)

Genuine Shimano Main Gear (part #100Y1) — the main gear (also called the drive gear) is the primary power transfer component in your spinning reel, converting handle rotation into rotor spin for line retrieval. A chipped, worn, or corroded main gear causes rough cranking, gear noise, and eventual failure under load. Cross-references with Shimano part number RD20317. OEM replacement ensures precise tooth engagement and smooth, powerful retrieve. Available from Offshore Tackle & Repair in Stuart, FL — your trusted source for genuine Shimano spinning reel gears and parts.