New here...Need help with McLane 20" reel

I need help identifying what my problem is with the rear axle on my 20" McLane reel mower. I don't know if this is the correct subforum or not. The problem is that the rear axle shifts from side to side 1/4". It causes misalignment of the chains and sprockets and it has caused the reel chain on the outside of the mower to rub into the chain guard. I have a video of the problem on Youtube if someone wants to view it. I've got a parts manual and all of the parts seem to be on my mower. I just can't figure out where that 1/4" is coming from. It seems like a simple spacer or bushing may have fallen out but nothing like that shows up on the diagram.

If this is not the correct place for this, can someone steer me in the right direction. I've emailed McLane but I don't know what's up with them. They haven't gotten back to me.

Thanks in advance.

http://ift.tt/1ENA5CW

Tom in Decatur, Ga