XX4WE slipper shaft has 5mm left and right travel and rubs?

[Fiddybux]

Did a stupid thing today when I couldn't resist a bash with the XX4, so I took it to a BMX track and ragged it. As usual whenever I got to a BMX track, it came home battered, a bit damaged, stones stuck in outdrives and full of dust!

Anyway, I noticed after cleaning it up that there was a rubbing noise coming from the slipper area. On closer inspection, and having taken the central gear cover off (I modded it to make this easy) the slipper shaft has about 2 - 4mm of travel back and forth (you can see the slipper nut moving in and out), and when you push it in it rubs on the inside of the chassis. Pull it out again and it's fine.

I'm sure it never used to do this...and just wanted to know if anyone know why this has happened before I go and take it all to bits.

Cheers all.