Joe, I respect your opinions because you are usually very accurate. I thought that you knew this but the BW4406 has been installed in at least two 302 Explorers with the electronic controls(TOD). The V6 4WD system operates a TOD BW4406 exactly like it does the BW4405.
Aaron was the first to do it, about four years ago, and someone else did it last year. It works, not as you might assume, but exactly like the BW4405 does.
The GEM module of a 4WD 98-01 Explorer will operate a TOD BW4406 transfer case, with all of the same components used for the BW4405. There are a few parts to add which don't exist in a non 4WD truck, and Aaron documented all of those. I am intending on very very soon completing my conversion.
The BW4405(and BW4406 in this usage) both require a GEM, TOD, and 4WD module from the V6 4WD trucks. Some wiring has to be added also, the 4WD harness to the TC, and just two wires I believe for the dash/engine harnesses. The power wire is not in the V8 or 2WD trucks, and the other is a speed sensor wire I believe. Those wires are th last things I will need to get done.
The BW4405 functioning includes a electromagnetic clutch to achieve 4WD in two of the modes. The 4WD LOW setting is the only one which engages the shift motor, unlike how the GEM of the big trucks controls a bW4406. The BW4406 will work just like in the V6 trucks, 4WD HI will be electronically achieved with the internal clutch, not with the shift motor.
I do have a 1998 Expedition GEM and 4WD switch. I will look into the GEMS to see if the 4WD control section is identifiable, to separate it. I would like to be able to achieve the full 98 Expedition control of the BW4406, but not first. Regards,