doc, i had a 3.3 pump failure once going down the road. no noise, just all of a sudden, the battery light came on, and the temp shot up to hot hot. got towed home, tore apart, then discovered it wasn't a shaft failure, but a bearing failure. the shaft poked almost out of the housing, but was contained by the impeller. no prior noises, but it WAS the original pump. had 152k on it. when it was apart, it had marks where the impeller had slightly gouged the internal housing, so i cleaned out the shavings, then flushed the system good both ways to get out the remnants so there would be nothing floating through the system to cause trouble down the road. like rocky said, toughest part of the job was the removal/install of the belt. took me about an hour, but i had to unreel the garden hose and wind it back up after flushing. this was on a caravan.