The flywheel shim is used on manual transmissions to position the flywheel to the proper clutch engagement tolerance after a flywheel has been resurfaced. Depending on your clutch system and the parts machined or replaced, you may need a flywheel shim. An improper clutch engagement tolerance can result in clutch engage and release problems. This may cause poor shifting and unsafe driving situations. If you are having clutch issues, shop O'Reilly Auto Parts. We carry flywheels, flywheel shims, and related parts for all your clutch system needs.