The starter turns but it sounds like it's grinding the flywheel even though the fly wheel has been checked and is good

Double check the tooth alignment of starter and flywheel. Also check teeth on starter for wear. If new starter was recently installed did they use spacers? Might have put to many or not enough.

Thank you for the infomation,but I still don't know where the starter is located,

undervoltage causes the solenoid NOT to go the full travel causing the lack of proper engagement~ clearly you battery is not putting out 12.5 volts at 50 amps~...so get a NEW battery (will no longer take a charge after ten years) and possibly new cables too, depending on the level of corrosion...use the wirebrush and safety goggles and make them nice and able to pull 50 amps, no prob....YES cleanup aisle one~