Thanks for all the replies. I have always been happy with the disk, and like I said, they're cheap at about 11.00 here, but I am just tired of it falling off all the time. It's the standard 10" disk, and it has the teeth on it. It fits on tight, until I pull. I also noticed it has warped right afte the first pull each time, and possibly that has something to do with it. I have had 2 of them, and each time I go through the same thing. It fits tight, I tow, disconnect, and it falls down in the bed of the truck. I try to put it back on, and it falls right off, not tight at all. If I wait until the next day or two (usually stay for a weekend) then it goes on tight again, but of course when I get home, it falls off when I unhitch. I like the idea, and I like not having grease on the top of the hitch, but I'm tired of farting around with the plate. Hoping this is a solution that works for me.
I wanted to share for two reasons, in case anyone had feedback on this style of lube plate, and then also to see if I am alone with the fact that the lube plates fall off, or if there are others out there. I wondered if I was doing something incorrect, but from the replies, it sounds like I installed it properly as I did what most do, I put it on, and then pushed it up tight to the pinbox.
If this works, I have a new lube plate for sale that I was carrying around since the others fell all the time... I was worried I would loose it and then be stuck with either looking for grease, looking for a lube plate, or hitching with neither to get home at some point. Glad that never happened and I guess I will try to return it to my RV dealer since it's still in the packaging.