On my Suburban, my main crank pulley seems to wobble a little bit. It's causing the tensioner pulley to jump a bit, and it's also causing very odd wear on an idler pulley (the one between my AC and crank). The wear it visible and shiny spots on the pulley, and when you actually touch the pulle, you can noticably feel the flat spots. I'm guessing that my harmonic balancer is/has gone out, but I wanted a few extra opinions before I break out the major tools and take my radiator and crud out for nothing. Also, if you think this is the case, could someone write a quick procedure on the easiest way to replace it? Thanks a ton guys!