I don't know if anyone has run into this, but I did, and I don't wish to go thru it again.
We recently went on a trip, and had the misfortune of entering and exiting a driveway that was steep enough to let the skid wheels touch the ground. I was going very slowly because I knew they would touch. Entering was no problem, but when I was backing out the sound that they made rolling on the ground was much different. They rolled for about 12" before breaking into pieces. Luckily the rear of the coach wasn't low enough to touch the ground after they both broke. I did some checking, and they are listed as being "Heavy Duty". I have contacted the manufacturer, but haven't heard anything as of yet.
I don't want to replace them with another pair of plastic wheels, so I decided to take things into my own hands and make a set of them that I know will take the weight. They are the same dimentions as the plastic ones, so fit is no problem. I made them out of billet aluminum.
The pictures below show the problem, and my solution.
This is the aluminum blank getting ready to be transformed.
The final results before inserting the new bearings.