Well I thought I was gonna wrap this thread up, but I have another related issue. It's not vibration thank goodness, but it was covered starting on page 3 of this thread so I figured I'd update it.
Sunday I put the front driveshaft back in and found the clutch or coil in the transfer case was locked up. Transfer case shifts into A4WD, 4HI and 4LO. It was very difficult to get out of 4WD once engaged. Took 20-30' of both forward and backward for IWE's disengage due to binding, I think the electric clutch or coil is locked up. This was a problem before that I thought the new OEM shift motor resolved, clearly it did not. Though it resolved numerous of other module and communication issues. With the IWE's unlocked it's still very smooth up to 80mph with the front driveshaft turning which is good due to the vibration hunt I just went on.
I took it for a 12mi trip Sunday afternoon. Once home I found the front driveshaft unlocked. It turned with an appropriate amount of resistance for the chain, diff and cv axles. I hooked up my scanner and found things seem to respond appropriately key on engine off. The front driveshaft rotated in 2WD and A4WD, it was locked in 4HI and 4LO as expected and it returned to unlocked when back to 2WD.
With the engine running the front driveshaft was unlocked in 2WD. Switched into A4WD and the IWE's locked but I could still rotate the driveshaft until the play taking up the play. Switched into 4HI and the driveshaft locked to the rear as expected. It would not unlock after this. I tried shifting multiple times, rolling it back and forth in neutral and drive. Rolled to the end of the driveway, no change. Drove a bit further at very low speed engaging/disengaging 4HI. Each time it was difficult to get the IWE's to unlock if I had turned at all inducing some binding.
Monday after the 75mi trip to work the front driveshaft was locked in. Tuesday after the same trip it was unlocked when I got home. The first time I shifted to A4WD the clutch locked in. I find it amazing that the coil engaging is utterly silent. I would think the clutches or the clutch plate would move just a tiny bit and could be heard. Did some of the pinpoint tests, that don't require accessing the 4WD module. Everything seemed okay, 2 of the tests(B16/B17) said replace the electric clutch. Of course I skipped some tests and will try to get through those this weekend. I have another used transfer case, but man I hate to remove the transfer case again to swap the clutch pack and coil.
Engine off
Switch positions verified via scanner, dash lights agree, as does the sound of the shift motor and shift fork movement.
Coil shows 1.96% in A4WD.
Coil shows 0 in 2WD and 4WD
I get voltage to the coil pin in A4WD, 4HI and 4LO.
Resistance on the spare coil is 3ohms, the one in the truck is 4ohms.
These 2 modules have readings that alternate for some reason. I found no other modules doing this.
4WD Module:
Clutch PWM status: Off-N/A
4WD Switch status: Selected setting-N/A(alternated the most by far)
Throttle position status: 16-N/A (engine off)
Vehicle Dynamics Module:
Air suspension at accurate trim: Out Correction-N/A
UBP Communication Bus Fault: No error-N/A
The one thing I have yet to find is how to actually directly test the coil. It gets voltage from the 4WD module, in fact at 100% Pulse Width Modulation set by my scanner it gets 12.26v. So can I just take a battery and connect positive to the coil wire and ground to the mounting bolts on the spare transfer case?
Maybe something in the clutch pack is getting stuck since if the clutch is disengaged after a ride it will engage as expected and then won't disengage.