What should be done if the cotter pin hole of a castle tension nut does not align within the recommended torque range?

The correct approach when the cotter pin hole of a castle tension nut does not align within the recommended torque range is to change the washers and try again. When a cotter pin hole is misaligned, it indicates that the nut is not seated properly or that the bolt may not be at the correct tension. By changing washers, you can adjust the stack height and potentially improve the alignment of the nut with the cotter pin hole. This adjustment helps to ensure that the nut is adequately torqued, and that the safety feature of the cotter pin can be engaged properly, preventing loosening under vibration or load.

In contrast, simply replacing the bolt without addressing the alignment issue might not resolve the underlying problem and may result in the same issue recurring. Using a different nut could also be problematic, as the original nut is designed to work with that specific bolt and load conditions. Leaving it as is would pose a safety concern, as the nut may not be securely fastened, leading to potential failure during operation. Thus, making adjustments with the washers is the most effective and safe solution.