My buddy recently bought a 4wd Trailblazer and installed a 3 inch Suspension lift. And we have taken it off road often but never abused it. Well he noticed that his 4wd wasn't working. He took it to a dealership for diagnosis and they discovered that the cv shaft has pulled out of the transfer case.
They said it was from the 3 in lift putting the cv shaft at such an angle.
He is bummed and wants to sell it if he cant customize it. He doesnt want to do a bodylift
I disagreed.. i dont think a 3 inch lift would put much strain on the drive train.
Any thoughts?

If the CV shaft was made just long enough for the stock height, then the 3in lift would pull it out. See if there is anyway to get a longer CV shaft.

but he used it that way for months. and took it off road often, Mud, Hillclimbs, Log Hopping, cruizing threw the fields. ect.

Did he ever "twist" the suspension to extremes often? If so that could have done it. Hell, my CV shaft on my stock height S10 back in the day was worn from me doing that.

Last month he was going down the high way and ran over a very large tarp that fell off a semi. He said it pulled the steering wheel right out of his hands.and it damaged his TB a little but he said his 4wd still worked afterwards. but i still think thats what did it.

replace it with a new one..then see if it breaks again