Installing Crossfire on an E-350 axle/wheel ??

The issue we had when we purchased the TST tire monitoring system is the valve stems on the E350-450 motorhomes would not let the senders mount and it was very difficult to add air when the tires needed air. Don't know if your having the same issue or not. But we ordered a new set of truck valve stems that came bent in such a way to allow easy air filling and screwing on the tire monitor senders. If that is your problem too, I will find the web site for the replacement valve stems.