This happened to me last year. Turned out I had slightly dented the flange on the back side of the hub, and as a result, the hub would not mate flatly to the CV joint. I had to take loose the upper ball joint again to get it apart enough to bend the metal back to the correct shape. After that, I had enough play in the shaft to get the rings on.

Even a child should have enough muscle to pull outward on the shaft to make the snap rings/spacers fit, as long as everything is put together correctly.

John B.

'87 Raider 2.6 Turbo Auto, Under Construction
'95 Montero SR, 35x12.5/15 BFG M/T KM-2's, Rock sliders, Qtr panel chop, gas tank lift, 2" BL, Aisins, 5.29s
'95 Pajero Mini
'98 Montero Winter Ed.
'04 Cadillac XLR
'03 Kawasaki ZRX1200R
'60 Ford Falcon 4Dr