Last I knew, HPTuners can turn off AFM.

I'd have a hard time swallowing that it is the transfer case locked in 4-High. There'* no way the universal joints would have survived your long drive. Test is easy:

(1) lift front wheels off ground
(2) start car in Park
(3) select 2-HI
(4) shut off engine
(5) try to turn front drive shaft
(6) does front drive shaft turn? "Yes"=good , "No"=bad

While they have it they should easily be able to test the AFM theory as well.

Both tests together should take less than an hour.

Next step as of today was they reset something with the transfer case due to clues that showed tcase locked up in 4wd. Worse case scenario he mentioned was to replace the tcase main coder motor. Anyone know if this sounds about right?

i did i turned out the AFM to see if it could make a difference, turned in on again, selected performane mode, then tow mode and then stock. None to my luck worked. what i do remember doing right before feeling that vibrating trans sensation was backing up trailer in a parking lot ful passenger turn, coming up to a pile of gravel for cement crew. Once i saw that 4ft mound of gravel they dumped i straightened wheels put it in 4hi and reversed the front driver tire over half that gravel. Once clear i selected back to 2hi, it gave me some trouble going back to 2wd but it went back. After that is when i noticed the dilemma at hand.

Oh and GM called me back about my complaint, "your user manual states any modifications will void your warranty" i was like what???? so if someone goes to a dealership for an oil change and they modified something on their vehicle you can just flat out pull that line out of the manual and void their warranty? this is total BS i told her amongst other things. When i heard her voice and name which sounded like a collector calling i knew i lost the case.

Only thing helping me is that the company i work with has asked me a few times to use my truck is willing to pay half the bill for anything thats being accrued. Still sucks but helps.

What clues?

Did they do the test I described?

Same folks that said that individual gears in the transmission were messed up?

Well, there are many instances where a mfg can and will void someones warranty if they suspect abuse/misuse. But, legally they can't void it because you changed some parts around.

https://en.wikipedia.org/wiki/Magnus...s_Warranty_Act

nope they didnt do that test, i picked up my truck today and that dagum shutter is still there after a new trans is installed.

this dealership isn;t who said my gears in tranny were bad thats up in Elk Grove CA, im down by Riverside CA.

Now that i have it back i can start medaling with it to see where this vibration is coming from. I feel like removing that front driveshaft to see if thats the ticket.

i stated all that, and still got me no where. its jibbrish for CA dealerships. its like this state is its own country or something. even GM rep said that they cant help me, they have to have a rep specifically for CA warranties call me back do to the laws out here. WTF!

Misfires do cause shudders when the TCC is locked up.