91 accord upper ball joint
 

I was looking at replacing the rotors and one thing I noticed after watching a youtube video on replacing honda rotors of this vintage (cause who woulda thunk you had to pull off the spindle to change a rotor) was that my upper ball joint (front end) does not appear to have a castle nut on it as I am used to seeing on every other ball joint I have ever seen. On this accord, it looks like there are two bolts and a "cap" that bolt onto the spindle and hold the upper ball joint to the spindle assembly as opposed to a standard castle nut and cotter pin.

All of the replacement uppers (even with control arm) that I have found all have a castle nut on the end of the ball upper ball joint. What am I missing here?

Any chance there is a castle nut under the "cap" I described above?

That is just a cover to protect the ball joint. There is a castle nut under that cover.