We have we fiat fr10, had ring gear on Flywheel replaced 2years ago, having starting issues, removed starter and ring gear is in horrible shape. We installed new ring gear, put starter on and have minimal tooth contact with starter. I have multiple starters order, been through books all say we have correct starter with proper number of teeth. We got ring gear from MINNPar, they verified ring gear to be correct. I am stumped....in fiat experts??
End play on the crankshaft. I know it sounds odd but something to check.
Is the ring gear pressed on the flywheel to the correct position ? Most flywheels have a land machined on them that the ring-gear has to be pressed against. But, I don't know about yours. Is it possible it was overheated when it was installed and it has now shifted out of position ?
Pictures of your ring gear and starter drive would help. How are you measuring tooth contact?
HeavyEquipmentForums Take a look at these pics and see if yours looks the same, check the same things, no solution, but plenty of suggestions.