I recently posted a problem. I had my fan come off twice. Once after I forgot to tighten one of the bolts holding th clutch on the waterpump and the second time I'm still trying to figure out. It was covered under warranty. Volvo siad it was the alternator bushing and or the fact that the alternator pulley does not exactly match up with the water pump pulley. Its a bit further back. They also said one of the pulley slots was to narrow and the belt did not fit right. My question is since the alternator was 9 months old I cannot believe that all of a sudden the pulley was an issue. The funny thing is when it happened I noticed one of the screws at the top of the fan shroud was missing and the fan shroud was half off after the second incident. Is the fan shroud more likely as I suspect?

Thanks in advance

Chris