Shaft isn't bent my friend. The S400's are notorious for carbon buildup on the turbine side rings. The dual piston ring design then adds to the drag. Best thing to do is pull the unit apart and slap new rings in while your at it. Should spin freely unless you have any other issues. How is the shaft play in and out and side to side?Shaft doesn't seem to be bent, it kinda feels like a new water pump or something. Like the drag from a new seal.