117989 – Woodruff Key .19" x 1.25" Hardened (#9) The 117989 Woodruff Key is a hardened steel key designed to securely lock rotating components onto shafts, most commonly used on the Number One Shaft – Forward Clutch in compatible lawn and garden tractors. This precision-machined key prevents slippage between the shaft and driven component, ensuring reliable power transmission and proper clutch operation. Manufactured from hardened steel for strength and wear resistance, this key is built to withstand repeated load changes, torque stress, and long-term use in transmission and clutch assemblies. Product Details Part Number: 117989 Part Type: Woodruff Key Style: #9 Dimensions: .19" x 1.25" Material: Hardened steel Function: Locks clutch and drive components to shaft Function Secures components to the Number One Shaft Prevents shaft slippage under load Maintains proper clutch engagement Ensures consistent power transfer Where Used This woodruff key is used on the Number One Shaft – Forward Clutch in a large range of Wheel Horse / Toro / garden tractor models, including: 12hp–24hp tractors Models with and without hydraulic lift Kohler, Briggs & Stratton, and Robin engine variants PM Gear and G-Series transmissions Professional, Hi-Speed, and standard configurations ⚠️ Due to the extensive model coverage, compatibility spans dozens of tractor models and production runs.Always confirm part number 117989 against your specific machine’s parts diagram before ordering. How It’s Used This woodruff key fits into the machined slot on the shaft and aligns with the mating component (clutch hub or gear). When installed correctly, it locks the component in place to prevent rotational movement. Proper seating is critical—do not reuse damaged or deformed keys. Suggested Maintenance Inspect key during clutch or transmission service Replace if worn, cracked, or deformed Never reuse a loose-fitting woodruff key Ensure key is fully seated before assembly The 117989 Woodruff Key (.19" x 1.25", Hardened) is a critical drivetrain component used in OEM forward clutch shaft applications where strength, precision fit, and long-term reliability are essential.
