Steering coupler not going on

I have read several posts regarding this situation on FABO and, like a few others, I am stuck.
I replaced my power steering box with a rebuilt unit. Upon trying to get the coupler on I ran into a problem with it only going on over the first set of splines on the steering box input shaft.
I read several posts about how to remedy this situation and applied their suggestions: I made sure the master splines were correctly aligned. I took a bore brush and cleaned the inside of the coupler where the splines are and added a little grease. I took a three edged fine file and made sure the splines on the input shaft were cleaned. I removed all of the bolts in the steering column, so it has movement. Continuous tapping on the coupler.
After applying all these tips, the coupler still only goes over the first set of splines. I am assuming all those who have run into this problem were able to get theirs to fit? If so, how?