As suspected the drive shaft coupling was smooth on the inside. The broken cotter key was laying under it.

Other problems came to view when splitting it. The left side of the torque tube bottom flange was broke off and the right side was cracked. When tapped with a hammer it fell off. Picked out what I thought was the easiest torque tube to get ready to swap with the broken one. I spent two hours cleaning the old paint and rust along with running a tap in all the holes to remove the mud dobber nests, rust and other crud. This morning while looking it over I noticed it is for a B and not a C. It does not have the holes for the steering box brace.  I looked over two that have the holes for the brace and decided it will be less work to drill and tap new holes in the one I started on at this point.  I took some pictures to share but still need to download them to the computer. I'll have them later.  It is raining and my camera is out in a took box. 

CrestonM wrote: How hard is it to replace that shaft?

I have split them at the transmission several times and don't consider it a hard job using what I have to work with.  I had a full gas tank which gave me fits. I cut some post to hold the back up that I wouldn't have had to do if I would have removed the gas. Same ole same ole, short cuts are not always short in the long run.

DennisA (IL) wrote:  When I restored my CA I found that the splines on the drive and trans shaft were half worn. I replaced both but it would be nice if there were something that would wear better. You don't see the gears wearing out the shaft so why does the driveshaft?

The splines on the transmission are rounded on the edges. I'll fix those rather than change shafts. I think I will drill out the hole and put in a larger grade 8 bolt. I might also use one of the thicker steel U joint drive shafts. I have some of them that are in real good shape.