[Marshall V. Daut]

There were clutch disk plates available during and since the Model A era that had no springs in the hubs to ease take-offs when the clutch pedal was let out. They are the so-called "Heavy Duty Truck" disks that were designed to handle heavier vehicles, such as AA trucks, whose drivers could have cared less about clutch chatter. It wasn't THEIR truck after all, rather the company's. They lasted forever, but made life miserable in a passenger car. These disks will almost always cause clutch chatter upon engaging the clutch. Over the years they have been sold by unscrupulous parts vendors to unsuspecting buyers at cheaper prices than the quality disks with CAGED springs. So, Model A people being the second-most parsimonious car owners on this planet (not far behind Model T owners), opted for the cheaper disk. These disks are still out there by the thousands. (Thanks, Rick's Antique Auto and J.C. Whitney!!!, et al.) Of the Model A clutch chattering problems I have fixed in the last 60 years, probably 90% were caused by this ^%#(& clutch disk. At one time I had a cardboard box full of 'em I had replaced before I finally threw them away to save future Model A owners the misery they caused. The remaining 10% chattering problems I experienced concerned disks, whose springs had fallen out of their bores or by badly scored/burned flywheel and/or pressure plate face surfaces. Not one was caused by the presence of grease or oil, which although were often present from over-lubing the throwout bearing, a failed throwout bearing, a failed pilot bearing or a leaking rear main engine bearing, only caused clutch slippage, not chattering. Others have apparently experienced chatter from oil or grease, but I haven't.
You can check which clutch disk you have by taking off the clutch inspection plate on the top of the bellhousing and looking at the disk's hub. If there are no springs present, that's why the clutch chatters. Not a fun job correcting this problem, but installing the correct disk WILL make life enjoyable again without that horrible and embarrassing clutch chattering.
Marshall