Well, finally got around to looking into that rattling noise coming from my 426 - long freeking winter up here in NY. Took the side cover off & there was a little, very little movement, just between the teeth of the CB gear & the teeth on the drive gear on the crank. No play at all in the drive gear & crank & the key was perfect. Still disasembled & blue lock tited back together, but still have that rattle. There is no noticable difference in power, starting, anything, just an annoying rattle. Dang.