Trailer wheel coming off

[organic antares]

As above the hub nut keeps coming undone, I think the problem is that the lock washer has lost the tab that fits in the keyway I am having trouble getting a new lock washer

 

[Kidds]

Laser guys will cut you a new washer with tab.

 

[Nearly]

 

[Dave W]

Clean it up and assemble with loctite.

Or drill and tap a grub screw 1/2 and 1/2 on the axle and lock nut

 

[John 1594]

Rob a tab washer from the opposite side of the axle, which in "theory" will be the self tightening side....

 

[Ley253]

Weld a bit of metal in to replace the tab.

 

[Mursal]

As above ........
I'd guess a Ford Cargo axle, might help locate a washer for the other side.
Will the two nuts lock against each other without the hub, threads OK on the stub, especially on the bottom?

 

[massey765]

seen them come off like that when bearing has not got enough backlash