I think I got it guys
Yes the spring ring engages into the rear part of the output gear
Took that spring ring off, swapped it with the spare one, and NOW the gear engaged it.
Put everything back together and no noise
I am guessing what happened ORIGINALLY was that the governor without the axial support locked down could move around and it was forcing the output shaft gear backwards...After some wear, when I disengaged cruise control, it jerked it just enough that the gear disconnected from the spring clip and I immediately lost all gears. That was the key event. While I was driving at 5mph for a few miles to the nearest rest stop, it was making the same fast clicking noise (although louder) that I was having trouble with for the last few weeks. Now that the gear is back inside the spring ring, its back in the correct place and now there is no noise.
I put my stethoscope up to the transmission, and I hear some metallic "tinging" noises, but maybe thats just normal. Either way, its not doing the audible tick that I could hear at anywhere over 1500rpm. I revved to 3000rpm and heard nothing.
I wont say mission accomplished until I've driven it for a few weeks, but I am pretty confident I got it this time
