SoCal, was it also your right rear tires like mine?
Wow, this is interesting to see and it appears to confirm what I thought happened w/ mine. I had no actual evidence as all of my parts apparently flew off into the woods, except that my inner wheel stem was gone.
What I question is that centrifugal force would cause the stem to pull out. The force would not be in the direction that would pull on the stem, rather, it would be towards the outside running surface of the tire.
I'm wondering if the stems themselves could be defective. There was a recall on Sprinter valve stems at one time, although an earlier model and not on the 3500 model.
Help! Valve Stem Problems?? - Sprinter-Forum
I'm also learning that its possible that the valve stems we have from the factory are rated only for 65 psi?? I have replaced mine w/ combination brass / rubber which are rated at 100 psi. I was also unable to locate a full-metal stem that would fit the Sprinter wheels. Read through this thread...
help!.... 65 psi valve stems? - Sprinter-Forum
After installing my new high pressure stems, I also installed new s/s valve extenders and the TireTraker TPMS sensors. Now I'm second guessing....and this is really annoying since I only have 1 weekend between now and my next trip!!