Axel has too much play

[motime]

145/100 series. Bought used. Approximately 12 years old. The external "shield" over the right axel will slide back and forth almost a 1/2 inch. I guess what I'm saying, is that the right axel seems to be coming out from tranny. Still works, but PM is required. Suggestions appreciated. Thanks in advance

 

[StarTech]

Double check things as it sounds just wheel slide back and forth on the axle and there is missing spacers. If axle was moving that much the axle keeper would fall out.