Left-Hand Primary Gear Nut for KTM 450/500 EXC/SX-F 2008-2026 - 78030029100

This genuine OEM primary gear nut is a critical component of your motorcycle's engine assembly. It is specifically designed to secure the primary drive gear to the crankshaft, ensuring reliable power transfer from the engine to the transmission. As an original equipment manufacturer part, it guarantees a perfect fit and meets the high-performance standards required for off-road and racing applications.

This part is compatible with a wide range of 400cc to 570cc models across the KTM, Husqvarna, and GasGas lineups. It fits KTM 450 and 500 EXC-F, SX-F, and XC-F models from 2008 to 2026, as well as Husqvarna FE, FC, and FS 450/501 models. It is also the correct replacement for GasGas MC 450F and EX 450F models, including specialized Rally Replica and Rockstar editions.

A key feature of this nut is its left-hand thread design, clearly marked with "LEFT" on the face to prevent installation errors. This reverse threading is essential for maintaining tightness against the rotational forces of the crankshaft during engine operation. Constructed from high-strength steel, it is built to withstand extreme heat and mechanical stress within the crankcase.

When replacing this nut, it is highly recommended to use a torque wrench to meet the manufacturer's specific tightening specifications. Proper installation ensures the primary gear remains seated, preventing potential engine damage or vibration. Always inspect the threads on the crankshaft for wear before installing a new nut.

Check compatibility list below to see if this part fits your motorcycle model.