Capacities - Approximate Fluid
WARNING: This page is about a different car, the 2003 GMC Sierra and 2003 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
When filling transfer case use 2.2 qts (2.1L) of Manual Transmission Fluid GM P/N 88861800 (Canadian P/N 88861801).