I wanted to install TPMS sensors on my dolly but was fearful that the high pressure valve stem that came with the dolly would flex, fatigue and break due to the weight on the end of the valve stem coupled with the higher RPM the smaller tires must rotate. Not something I wanted to happen on the highway and the loss if tire pressure would be sudden. I tried making a brace for the valve stem, which seemed to work OK but it wasn't a long term solution since some local towing showed the braces were loosening up.
I first spoke with Innovative Balancing, who make the dynabeads that come with the newer ACME dolly and are used to balance the tires. They recommended adding 1/2 oz of additional beads to compensate for the sensor just be safe. In the following photo you can see that you simply remove the filtered core of the valve stem and slowly add the beads. These are available in kits for motorcycles so I bought 2 oz to do the two tires on my dolly and my spare.
With the tire deflated, you can simply put the tire on a piece of plywood and step on the tire near the valve stem, that will easily break it free from the rim. Once you break the bead, you can hold the tire down and carefully cut out the rubber valve stem. Then I installed a 416 metal valve stem from Blackjack Tire (Link to Metal Valve Stem
) and snugged it in place. (This was the second metal valve stem I bought and these fit very nice.) Once the metal valve stem is in place, remove the valve core that comes with the valve stem and install the original filtered core seen in the above photo that came with the dolly (or if it is an older tire, filtered cores are easily obtained at a tire shop). Once installed, re-inflate the tire and mount on the dolly. With the exception of the spare, where I dropped the metal valve stem into the tire, it took less than five minutes per tire to swap out the valve stem in my basement. Here is the final installation.
Haven't road tested yet with the sensor in place but this should provide a long term worry free solution to adding a TPMS sensor to the dolly. Hope someone finds the information useful.