FWIW, you can address spinning, egged caps by putting strong loctite around the outside of the bearing cup. It will immobilize everything and keep it from getting worse.
In my experience, most loose yoke ends are actually due to corrosion. The seam will rust up when you're parked and then the next drive will beat the rust out. A few cycles will make for a loose fit. When I assemble u-joints I tend to place either loctite around loose-fitting cups, or anaerobic sealant around tight-fitting cups to keep moisture out. The only reason I use anaerobic instead of loctite is to make disassembly easier--you could just as well use loctite in all cases.
Caterpillar sells a high strength bearing retainer compound that is the best in my experience. It goes on green and you'll need to heat it with a torch to get it back apart. I suspect it's just a re-branded permatex product, but I don't know for sure.