After returning from the trip and looking over the bus I was unable to find the rubber valve stem stabilizer on one of the dual drive wheels. There are two on the drive axle. Each is a custom molded black rubber piece fitting over the long valve stem shaft from the inside dual but set in place on the outside dual.
OK, no big deal ...BUT... while reading about this part is extremely important to the longevity of the valve stem. On the Alcoa site they have all the different types available for there wheels along with available dealers.
According to Alcoa this seemly unimportant piece of rubber eliminates valve stem failure on the inside duals.
I ordered 2 new @5.20 each
In looking at the old verse new remaining rubber stabilizer stem hole is slightly larger showing some wear from movement.