Kevin,
If I am following you description correctly I think you need to get the 4 step pulley cluster, thrust gearing and it's washer more carefully aligned, it should all slide in without any forcing.
Check also to see if spring loaded oiler pads have not got in the way of inserting your spindle, it is very much a juggling match I'm afraid
And the obvious question of course, is everything in the same order as it was before you pulled out the old spindle?
Regards
Brian