Not sure what to call it, but I'm trying to find the little cap that goes over the middle of the wheel where all the grease it packed it. Somehow ours fell off on one side! It's a coleman utah '95, but pretty sure they're pretty universal. Grease it all packed in there, but the cap came off so we covered it with tape so I'd stop bumping it and getting covered in grease. Got a new cover from the RV store and it LOOKS like it fits, but it's just the right size so it matches up the the rim, but won't tap in there. Is there either a different one you all recommend or a trick to putting these darn caps on?? Any help is appreciated!