I have a 9000H MEC that I bought new about 8 years ago. Lately, after about loading 100 shells, the machine is making a loud CLUNK halfway through its return stroke as the machine is cycling. When there isn't a shell in the deprime/resize station, it doesn't make the noise. It doesn't make the noise until I have loaded a few boxes of shells, however. I have a suspicion it has something to do with the collet or the fork that operates the collet under the base of the machine, but I thought someone out there may have experienced this problem and have a quick diagnoses and fix. Thanks, Paul.