I have no idea if this is the case but when mechanical items fail there is a cause. Sometimes a good portion of that failure can be attributed to improper use and care. Was the failure due in any part to that? What is the expected lifespan of your part? We're all maintenance schedules strictly adhered to and recorded? Could the parts that failed have been ordered in advance and therefore been on hand for quick replacement? Those and more questions would come into play if this goes further. Again, I have no idea of the answers.