Vehicle makes grinding sound when I start it. I believe it is either the starter or fly wheel.
Sounds like you might be right. If the teeth on the flywheel are work, a loud metallic grinding noise will be heard when cranking. If this has gone on for a bit, the starter drive might be worn as well. The starter drive is the part of the starter that actually engages the teeth on the flywheel to turn your engine. The normal repair procedure will entail replacing both the flywheel and starter. If you replace one and not the other, you run the risk of ruining your new part. This is a labor intensive job that requires transmission removal. I suggest getting a technician to verify that this is the concern and help you correct it.