Not sure if I have a problem with landing gear or not

I recently had a stripped gear on one side of my landing gear, and it would not move at all, either up or down. For what it's worth, I had to replace that one side only. I'm not a mechanic, so I had the dealer do it: $260.

The mechanic told me what probably caused the problem: raising the landing gear too high. He painted a line on the leg and told me never to extend higher than that painted line. I wish that they came come the factory like that.