as an example, what do you suppose happens to disc brake rotors and the brake drums on cars when the cars or trucks are stored for a period of time? They rust. What has occurred is rust on the flywheel and the metallic parts of the clutch disc. You might need to remove the trans and bell housing and sandpaper-emory cloth the flywheel. If you installed a clutch disc with metallic engrained into the disc, you might need to replace that. Also, the pressure plate springs and fingers probably have a good coating of rust on them too.
People should never, ever "store" a vehicle, vehicles are meant to be driven. At least once in awhile, go start the vehicle, drive it til it gets fully warmed up, put fresh gasoline in it with Stabil, and just keep things flowing.
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