Why do the shift forks and drum go out on 01 660s. because i have one and i got it bored to a 686 and the second gear shift fork just went out. i was just wandering why they do that and what i could do to make it not go out. but i was talking to someone they said to upgrade it to a 02 or up. so i think im just going to do that. but i was just wandering why they go out....any ideas??