I had problems with the clearance lights leaking from the INSIDE. Even tho the base was sealed around the edges, water would get under the lens and leak in to the coach.
I switched to SEALED LED clearance lights, of the same size, and that solved the problem. These lights are primarily used on boat trailers and do not have a removable lens to leak. Once the base is sealed, problem was solved and they have now lasted for several years. The plus is that they are also brighter than the original incandescent bulb clearance lights.