[83cutlass]

On the new body style 2002 Bravadas it almost always the encoder motor that has failed. There is a bulletin out:
#02-04-21-008A: Shudder, Rocking Motion, Binding, Feels Like Vehicle is Stuck in 4WD (Crow Hop) When Turning at Low Speeds (Replace Transfer Case Encoder sensor and Reprogram TCCM)
It describes changing the t-case fluid, replacing the sensor, and reprogramming the T-case module. My experience has shown its better to replace the whole encoder motor and not just the sensor.