Please Help - Hubcaps/Wheel Covers Falling Off!!!

[wldcat10]

Ok I have a problem with my wheel covers falling off! I put on some new tires on my '70 lwb this past Friday and put on my wheel covers just before leaving the tire shop. I made a u-turn and there goes my front passenger wheel cover rolling into the middle of the street, as I pull over and brake my front driver side wheel cover rolls off. So I go and grab them and figured I would just put them on later. So later that afternoon I put them on and pull out my driveway, as my front tires are rolling off the slanted concrete (where the sidewalk meets the stree) my front left wheel cover pops off. I brake to get out and get it and my other front wheel cover pops off!!! Am I doing something wrong??? The wheels I putting them on are smoothies, when I put them on it feels secure but they still pop off! I took pics of both wheels and wheel covers. Do I need to pull out/adjust the small teeth on the back of the wheel covers? Please help me out! I just want to take my truck for a little cruise without having to worry about my wheel covers falling off and not having to dodge traffic for my wheel covers! Any help is appreciated! Pics below!

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