What causes rubbing turbines in T53-L-13 engine?

Rubbing turbines in the T53-L-13 engine can be caused by several factors, including misalignment of the turbine components, excessive wear or damage to the bearings, and thermal expansion issues due to high operating temperatures. Additionally, foreign object damage or debris ingestion can exacerbate the problem by altering clearances. Regular maintenance and inspections are crucial to prevent these issues and ensure proper engine performance.