Since there are some obviously very knowledgable people around here let me ask you this question. A couple years ago my time cutter developed a squeek in the front wheels. It's a loud obnoxious one that happens more the hotter it is outside. I can grease the wheels through the grease nipple until it starts squirting out and it will shut them up for a couple of mowings but then they start right back up. Is this a common issue on these things? Can the bearings be replaced? Do I need new wheels? I live in a windy somewhat dusty area could they really be getting dirty that fast? It's a 6 year old timecutter, model 74633.