Does anyone out there know what the purpose the bolt on the end of this starter is? Starter just quit working all of a sudden. Selenoid clicks but the starter won't turn at all. This bolt gets hot immediatly if you hold the key for just one second. The bloody things is only a couple of years old ( just past warranty) and it's hardly done any work at all as the tractor has always started right up. Talked to a couple auto mechanics and they don't know what it does. Parts guy and mechanic at the DEALERSHIP don't know either.