66 dart 225 auto starter ?

so need a new gear drive then ,cause the teeth are chipped
oh it was spinning ....and grinding
think i have one from the 65 parts truck
If it was grinding, then it was not kicking out far enough to engage the ring gear. I've seen some dirt and grease gum up the slots in the starter shaft and bushing and cause the starter bendix to stick. You might just try cleaning it up real good.