If your coupling is looking rough, you may want to take a peak at your thrust bearing as well to see is there is any damage there also.
Vibration analysis can tell you the story of what's going before the next failure occurs. As others have indicated it sounds like an alignment issue.
Anyone have any experience co-firing PRB coal and rail road ties with a traveling grate stoker? One of the main issues I'm having is Coking on the surface of the grates which prevents fuel from achieving proper air flow and causes the operators to have to rake off the grates quite often.
Is...