Take the shaft out and inspect before you decide on a plan. I would only use a glue that was "rated" for this sort of use, my experience has been that over expecting glues has not resulted in good outcomes. Bear in mind that a cross pin while tight initially would only have a small fraction of the cross sectional area that a spline has for transmitting torque, it would be much easier to break than even a poor spline.
It might be that a new yoke, pulled all the way in with a retaining bolt would fit well, at least where the new and the unworn sections mated. It might be more engagement that you have now and it would no longer move with torque. You could glue the new yoke on too, just because it was easy and might offer a little more support. I suppose a guy should make sure there was clearance at the transmission face for the new yoke to pull in, the yoke should bottom against a shoulder when the bolt is tight...
Do you have a "machine shop"?
Dan
