I have an 03 Civic EX with almost 160K. For the past 30K or so I've had what I believe is input shaft bearing noise getting slowly worse. It only makes sounds when idling in neutral with the clutch not pushed in. Otherwise, the trans works normally. All gears engage like normal, shifts are smooth, just the grinding sound when I let off the clutch pedal in neutral. Obviously, I try not to do this at all, keeping the clutch pushed in in 1st gear when at stop lights, etc. At this stage of the car's life (I'm the original owner), it gets driven 3-5k per year and is used almost exclusively for commuting to work (a 5 mile trip each way). I want it to last as long as possible, but don't want to sink a ton of money into it. Considering the low mileage it now gets, if I can get another 30k out of it, that could be 6-10 years. Do you guys think it's imperative to get this in a shop, or keep driving it til it gets worse? What is worst case scenario with a bad input shaft bearing?