I had to remove a wheel to replace a leaking valve stem today. The shop asked if I wanted the tire balanced, I said sure and how large of a weight did the wheel have on it before balancing? He said there was no weight and that it didn't look like there ever had been a weight installed. It took 3/4oz to balance the wheel. I looked and none of the other three wheels have any weights, which means none of the wheels were balanced from the factory. This is a bit concerning as it's very rare that a wheel is balanced without weights being added. For the last 17,000 miles, the wheels have been shaking the trailer, probably not much, but some. Do you think not balancing RV wheels at the factory is normal?