the ring gear is on the flywheel take the starter out and you can see the teeth around the outside of the fly wheel, get some one to turn the engine with a spanner on the crankshaft pully bolt as thay do this you should be able to see if any damage is done to the teeth when its turning, dont put your fingers in there.


also yes it is possible for you to have an earth fault on starter take all of them of give them a good clean and put back on i would also do the ones on the body.