Ok, I got it. I have never had the front gearcase off before, so I wasn't thinking. It just barely slipped off the final frive output shaft, but I realized I had no way of telling where the spring was. I went ahead and pulled the shaft out, and the spring was in the coupler. I put some more Honda Moly 60 in there to hold it in place, then slipped the shaft back in, and got it re-engaged with the rear output shaft. The spring is in place, because I can push in on it, and feel the spring compress.
Now I have another problem. In trying to get the bevel gear case lined up with everything, I damaged the gasket. Now I have to order another one. I have decided that the next time I do this, I will install the front gearcase first, then the rear gearcase. It is very difficult to get the front gearcase in place while trying to engage both the U joint and the damper, both of which have springs that try to push the gearcase out and forward at the same time. I also found that while the manual doesn't say so, you also have to remove the left side exhaust pipe from the head. So I also had to order a new crush gasket, and a new graphite gasket for where the pipe goes into what you guys call the goats belly, as the old one shreaded when I removed it.