Modification of Wheel Simulators on MB Sprinter
I am the owner of a Thor Freedom Elite 24fe. I suspect that my concern may also be applicable to other Thor models on the Sprinter chassis using wheel simulators. I noticed a few months ago that the wheel simulators were starting to gouge the brass tire valve extension on the rear dually wheels. If you are one of those owners, I suggest you check your tire valve extensions. I cannot envision a situation where this, over time, would not lead to the extension being worn through causing a sudden loss of air pressure to that tire. The extensions are made of brass and that is a soft metal.
The original holes in the simulators are very difficult to align with the valve extensions so that they do not come in contact with the metal surrounding the holes. Putting on the simulators after removal was a one hour job to try and align the extensions with the holes for minimum metal to metal contact. Unfortunately, I found it impossible to get it perfect. Also, tire monitor sensors could not be attached without an additional extension, something I didn't want to do. I live in a state that requires yearly safety inspections requiring that a rear wheel(s) be removed to check the brakes. The technicians always mess up whatever alignment I have achieved.
My solution was to make the holes larger. I know some of you will say that the holes should be smaller. For my purposes, I decided that appearance was not as important to me as peace of mind and ease of installation. The size of the hole also makes it easy to align the extensions. With the simulator installed on the wheel, my fingers can fit inside the cutout to attach and align the extensions the way I want. Before, I had to guess at the angle, install the wheel cover, and then start over when the angle of the extension was wrong. Additionally, I can install my tire monitor sensors without having to use any additional extensions.
The 1st attached photo shows the steel wheel without the simulator and the MB (or maybe Thor) tire valve setup. The 2nd photo shows the wheel simulator in place without the center hub and the 3rd photo shows the simulator with the center hub in place. The valve extensions do not flex (solid) and there is no chance of metal to metal contact with the edge of the cutout.
You may also want to examine your front valve extension. On my model the extension was attached to a rubber tire valve and it did flex quite a bit. The flex can cause the extension to contact the edge of the simulator hole also gouging the brass. The solution for the front is to replace the original rubber tire valve with a metal valve stem that cannot flex.