The best way to tell if you might need a flywheel replacemnet is by sound. When you start your car and hear a high pitch griding nosie and the engine does not crank over, this is a definate sign of worn teeth on a fyl wheel. Also if it starts to crank...skips..then goes back to cranking, this is another sign of the flywheel needing to be replace. Of course removing and inspecting is the most precise way to tell, simply listening can help save some time.
Fig. 2: Inspect the bolt threads. Replace any damaged bolts