I have a 91 350sd that began to leak tranny fluid today. When I inspected it, I found that it is leaking on the passenger side of the tranny where the governor shaft sticks out. It appears that the o-ring has gone bad and there is a snap ring and cover outside the o-ring. Before I tear in to something that I really am unsure of, can I just remove the snap ring and cover and replace the o-ring or is a bunch of stuff going to come flying out? It looks like a simple fix, but a tranny tech I am NOT!!! Any help out there?