Where does front differential engage ???

[Seasparrow]

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Obviously at the center diff, but read on. It takes a lot for me to get under my truck. I drive up on 4 wide heavy wooden platforms to grease my driveshaft. I forgot to take it out of 4WD and it of course would not spin freely. I got out, took it out of 4WD, turned the shaft to get to the zirks and greased the fronts.

Question, where does it engage? obviously at the center diff but if it spins freely it also has to disengage from the front diff correct? So the question is, what disengages the front diff.

 

[y=mx+b]

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Obviously at the center diff, but read on. It takes a lot for me to get under my truck. I drive up on 4 wide heavy wooden platforms to grease my driveshaft. I forgot to take it out of 4WD and it of course would not spin freely. I got out, took it out of 4WD, turned the shaft to get to the zirks and greased the fronts.

Question, where does it engage? obviously at the center diff but if it spins freely it also has to disengage from the front diff correct? So the question is, what disengages the front diff.

Based on what I understand, ADD (automatic differential disconnect) unlocks the passenger side from the front differential and the front driveshaft is disengaged by the tcase. In my head, the front driveshaft will spin freely by hand in 2wd is because the differential acts like you're stuck: The passenger side output will act like the unstuck wheel and spin because its disconnected within the diff, and the driver side will be the stuck wheel and not move. Seems like there could be a lot of wear on the spider gears in 2wd if the ring gear isn't turning, but they're not under an engine load, so I dunno about that part. Hopefully someone that understands a bit more about ADD will chime in.

Hard to see with these pictures since I was focusing on the CV, but the box with the wires is the ADD actuator. This is viewed in from the passenger side wheel well.