2005 Tahoe Awd Transfer Case Noise

[sjsflyer]

I have a squeaky rotational noise coming from the transfer case on my 2005 Tahoe AWD model. It only happens when driving forward and is synced with the drive shaft speed. I went under the truck, put it in neutral, and spun the rear drive shaft forward/reverse. Sure enough, the noise occurs in forward only and is not the u-joints. Sounds like it is an internal transfer case noise. The vehicle has 63,600 mi. and is the all-wheel-drive model. Any thoughts?

[gmtech4]

how do you know its not a u-joint?,sounds like it to me

[sjsflyer]

how do you know its not a u-joint?,sounds like it to me

 

 

I thought u-joint at first. But for one, it only makes the noise in forward. Two, when under the truck, the squeaking noise seemed to be coming from

inside the tranfer case as I rotated the rear drive shaft. Also, there is no clunking noise, just a rotational squeak...