sector shaft question '55 F100
 

Im currently rebuilding the steering gear box on my 1955 Ford F100 and just put the new roller gear into the sector shaft. Is the gear supposed to be able to spin freely before i put it back in the gear box? I cant get it to move at all. When i put it together i had no problems, everything just slid right in. Also, the stock pin that held the original sector roller gear in place was mushroomed on both ends. The new pin is hardened steel and i have no idea how i would mushroom the ends. Would it be a problem if i put a tac weld from the pin to the sector roller gear housing?
If anyone could shed some light on this itd be much appriciated!
Thanks.