Yesterday I installed a small SPST rocker switch to disable the alarm audio sensor. This will allow me to leave my dog in the locked T4R and she won't be able to set off the alarm by barking or other noise.

Today I addressed a drivetrain rumble present at highway speeds (60 -75). Physical inspection of the cardan & u-joints on the axles looked fine so I removed the rear driveshaft and took it for a run in 4WD. The vibration was gone so I replaced the rear u joint and when I went to install the driveshaft I discovered a lot of play at the companion flange at the back of the transfer case.

I installed the driveshaft and took it for a test drive and found that the vibration had changed- gone under load but present when lifting off the throttle.

I'll get a replacement nut for the companion flange and see if tightening it up will solve the issue. If not I'll have to replace the flange.