If the output bearing is larger bearing on the damper assembly, then the mechanic at my dealer gave me an explaination of the failure. First, my failure was the smaller of the two bearings on the shaft, so, although I had a failure, i guess it wasn't the actual output bearing. Anyway, the mechanic showed me a slinger or sorts installed on the shaft next to the larger bearing. An oil slinger picks up oil and slings it on whatever is near it. This mechanic said that was the part that could be installed backwards. The smaller bearing on my bikie that did fail, was sealed on both sides. Not sure how it receives oil (maybe leaches). I didn't get a chance to study the shaft and parts....only got a minute or two to disucss.