Have you reprogrammed your TST monitor for the pressures stated on the door plaque, not the max side wall rating.
On ours, the fronts (tires rated for 80psi) door jamb and weight load requires only 65 psi. My TST monitor is set for 65 psi front axles. It will alarm at -10% or about 59 psi. low or +20%, about 78psi for a high.
As for the rear duals, you will need metal valve extenders, various shapes and length to get to the outside of the rim. I'm sure others will chime in as to the various options. Without the extensions and with the screw on TST sensors, you can check and ad air with a dual head air guage/filler.
Ken
