Flywheel Inspection
After engine removal always inspect the flex plate or flywheel for damage or wear. A flex plate will be found on a vehicle equipped with an automatic transmission and a flywheel used with a manual transmission. The flex plates wear and crack around the bolt holes. It must be replaced if it has small cracks forming because they will get deeper in time. Both of these have a starter ring gear attached. If the ring gear is damaged on a flex plate the flex plate should be replaced. Typically the ratio between the ring gear teeth and the starter pinion gear will be around 15:1 or 20:1.
If the ring gear on a flywheel is damaged it can often be removed and replaced. If the flywheels surface area has light surface cracks or scoring it can be resurfaced. Resurfacing a flywheel insures that it will have the proper flatness and smooth finish. The surface area must be smooth and not warped. Warpage reduces the contact area of the flywheel allowing it to slip. This slipping causes excessive heat, hotspots, and glazing.
Whenever removing a flywheel from an engines crankshaft mark its position to the crankshaft and replace the flywheel in this same position during reassembly. This insures the balance of the flywheel to the engine. An unbalanced flywheel can cause excessive drivetrain vibration.
