Double nut spindle axle nut setup

I've taken this setup off of trailer in renting. Is there missing hardware? What keeps outside nut from loosening up?
From left to right inner nut, ring, outside nut

 

Pictures?

 

The locking device is a small Allen screw in the washer/spacer with the holes in it. That's what small threaded holes are.

 

There were no Allen screws. Does anyone have diagram of setup?

 

You can get a new washer with new locking screws. People dont see them and force them off shearing the screw off.

 

The inner nut is the important one. Get that one set. Then you put the washer on to lock that inner nut in place. Tab in the slot on the spindle keeps it from spinning, and the knob on the inner nut fits into a hole to lock the inner nut in place. If the hole doesn't QUITE line up, try flipping it over. If they're still off, back that inner nut off as little as neccessary to get the knob in a hole. The outer nut only gets torqued to 50 or so ft lbs...only thing it does is hold that lock washer against the inner nut. It won't go anywhere.

 

This is a very common set up on bus axles.

You are missing a big star washer that has a tongue to fit the groove in the spindle, same as the lock ring.

It goes on after the lockring and before the outer nut.

After final torque of the outer nut, you peen over at least two of the tabs on the star washer. That is what holds the outer nut in place.

 

I've replaced it with stemco pro torq

 

That is an old tried and true set up. The allen set screws came out much later. I do not use them as I believe those were for liability against ambulance chasing attorneys. Installed correctly the nuts are locked together and do come loose.
There are several discussions about wheel bearing adjustment in the top right search block.

 

There's a notch on the spindle.
The inner nut has a little pin which faces outwards. Tighten the inner nut until it's almost snug. Align the washer so that the tab on the inside of the washer slides into the notch on the spindle and the pin on the inner nut goes inside one of the holes on the washer. The washer will prevent the inner nut from turning. Put the outer nut on and torque it down to the torque specification which is probably more than a hundred and fifty pounds. It's just like doing an F-350 spindle nut except probably bigger. I got something similar on my Chevy Tahoe.