Front axle noise

[Bever22]

I have been hearing a noise in the fron axle on my 1528 hydro. It sounded like a clunck and just this week I was watching close and I could see very little movement (forward & back) in the axle when I was doing some loader work. Today I was doing some greasing and I found this bolt loose. It is the horizonal one behind the grease fitting, it was backed out just as pictured and I can turn it with my fingers. I was wondering if anyone knows ho tight this needs to be because there is a locking nut on the inside and if this is what could be making this noise?

[Bever22]

Fixed with dealers help, there great.

[KennyV]

This is the way to preload this swivel point...