ok if you put your truck in auto 4wd and turn it of with the gear in park. no eng running no key in the ignition. if you lift your truck up with a lift not a drive on but a swing arm style and you try to spin your drive shaft what happens? then if you try to spin your front drive shaft what happens? i'm talking by hand grabbing the drive shaft and twist it.

 

neither one off my drive shafts will turn with the truck in auto 4 if the transmission in park.

 

me too.

 

ok so mine is not auto trac for sure then. with mine in fulltime 4wd (i guess)
second button down its either that one or 4lo no other choice. so in mormal with tranny in park i can spin my drive shaft and all four tires will spin. not all in thesame direction but the will all spin. just trying to prove my theroy (spelling) that my tahoe is full time 4wd like the hummer and not autotrac.

 

The way I have read onthis site and otheres is as follows: All auto 4wd does is engage the transfer case but not the front Hubs/Dif... You should NOT be able to turn the front shaft unless the truck is in Neutral or in 2wd...

 

the actuator in the front diff will engage if the computer notices slippage, T-case is full time engaged, unless you put it in 4-Lo then everything is all the way engaged.

you shouldn't be able to spin the shafts while in park because the transmission "shouldn't" allow them to spin. you can spin the tires because the diff, but not the driveshaft. when autotrac is engaged and you hit some mud, the computer times the output shaft from the t-case to the dront diff and the speed of the gear basket in the front diff and engages the actuator on the front end when they're at proper speed so they will mesh right. if i forgot something or I wrote something wrong please correct me, I just woke up lol

 

but mine is not autotrac. i have the same transfer case as the h2 which is not auto trac its full time 4wd. the front and rear axles can spin at diffrent speeds unless locked in 4lo for me or 4hi lock in the h2's. i have a borgwarner t-case. it says so right on the case itself. wen i went to put my yank in i could spin the drive shaft in park and all four wheels would spin. but the fronts were spining the oposite direction of the back. kinda like if you have an open diff in the rear and you spin one tire the other spins the other way. well my tranfer case uses an open diff in full time mode but locks in four lo or in the h2 4hi lock or 4lo. i'll find a good h2 web site and ask those guys what happens when they do the same thing. oh and i also have the same rpo code as the h2's bw 4484 t-case.