and if you put the axle in the diff but not into the spindle/hub?

Yeah, I do the same with my truck...well, cuz mine doesn't have auto for one, just 4 hi or lo or 2. But yeah, good tires and the LSD rear is fine. My Pacifica has an option to turn off the ESP (electronic skid protection) but this Rainier has NOTHING. No switch for 4 hi or lo or AWD or anything, and no switch to turn off AWD completely like my Pacifica. My understanding is the Trailblazers and Envoys have a selection but Rainier and Bravada do not.

Same clicking happens, cuz I did try that, but not to rule out the the hub...a buddy told me that the CV axle shoudl wear out before diff does, so even with high doubts that the axle itself was bad, I bought one and tried it. I guess I should add that on the jack stands, the front drive shaft rotates when running in gear, but the CV axles do not...obviously the computer doesn't think the rear wheels are slipping.

Having 4WD(4x4) issues? Look inside! - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum
some good info on how it works

Yup, was on that site first and found that link and read mostly through it, didn't seem to have what I needed. Thanks for feeding me the info though, soon you'll I'm sure send something that I haven't already stumbled across in my journeys of finding this issue...Basically I'm trying to avoid dropping the differential if I don't have to, so I want to find out everything I can so maybe I can fix it in the vehicle if the problem seems to be towards the edge of the diff, or if its more deeply into the middle and it'* gotta be dropped. Cuz it doesn't appear to just "drop" out, it looks like the undercradle is in the way and may need dropped, or motor mounts released and motor lifted and shoved over a bit.

Is there not an edit option like most other forums?? or am I just blind?

Anyway, just to clarify, I don't think there is anything wrong with the functionality of the vehicle, it is just a hum like a wheel bearing while driving, but a clanky chatter type sound when up on jack stands.

Sorry, regular members do not have the option of editing posts. We would rather have you make another post to "correct" the previous message as oppose to making the correction in the original post and people not notice it. Especially in the technical threads.

Ah, ok, its fine, just that most forums I frequent they get irritated for making a bunch of posts because of errors or afterthoughts then hound you for trolling to up your post count...I guess it just a difference of the typical communities.

Yes, you are correct.

that site says the awd trucks shouldnt have a disconnect in the front only the transfer case

Hm, well, this Rainier has a disconnect, and no selection switch what so ever, so it'* gotta be AWD. Maybe the reference was to original AWD where literally all wheels drove, where as this is a traction control AWD, so it has a disconnect. Not sure.