You need to adjust the pressure plate fingers. I had that exact same noise after splitting my cub to replace the rear main. I figured while I her split, I'd adjust the fingers where I could get at them directly, rather than through the hand hole. Unfortunately, I forgot that they are supposed to be checked with the pressure plate bolted to the flywheel, so, of course, they [url]weren't[/url] properly adjusted after all. (I should have figured something was wrong when they measured so far off, even though I had no problem before splitting
Got her back together, and got that same noise. Adjusted the fingers again (through the hand hole, this time), and she was fine. Adjust the fingers first, then adjust the free play so you have the proper clearance between the TOB and the fingers. A paint stirrer is the perfect thickness for setting the clearance.