1. Clamping piece deformation: The clamping piece is deformed due to collision or other reasons and cannot be installed on the axle smoothly. The solution is to replace the new clip.
2. Axle problem: If the axle is not straight or the surface is rough, the clip cannot be installed smoothly. The solution is to clean the shaft surface and polish or coat it with lubricant if necessary.
3. Wrong installation method: If the correct installation method is not followed, the clip cannot be installed. The solution is to refer to the installation instructions or seek professional guidance.
4. If the above methods still can't be solved, it is recommended to consult professional maintenance personnel or go to a repair shop for inspection and maintenance.