Agricultural machinery often works in harsh conditions filled with mud, water, dust, sand, and heavy loads. If the oil seal is not properly selected, it can easily wear out early, causing oil leakage, contamination, and frequent maintenance. This is especially common in tractors, harvesters, seeders, and tillage equipment. In many cases, premature seal failure is not simply a quality issue. The real problem is that the sealing structure, material, and performance do not match