The threaded collar does not need to be removed to slide the u-joint ball back on the torque tube. The collar does need to be removed to replace the felt packing seal underneath. To pull the u-joint ball back, simply remove the 4 bolts from the rear of the transmission. If I recall correctly, you will need to jack up the back of the transmission to get the u-joint ball flange back past the rear transmission mount. Clear as mud? Once you get into it, it will make perfect sense.

The trunion is the + shaped piece of the u-joint.

I just worked on my u-joint about 6 weeks ago. I was a little nervous going into it, but came out with a good understanding of how everything works. Its not difficult. Just be observant about how it is all put together. Good luck and keep us posted.

-Tim
'51 Chevy 3104 w/'56 235, 848 Head, HEI Dizzy, Corvette Cam, Split Manifold and Dual Carter YF's