Transfer Case
WARNING: This page does not describe the selected car, but rather 26 other vehicles, including the 1992 GMC Yukon, 1992 GMC Vandura Special, 1992 GMC Vandura, 1992 GMC Value Van, and 1992 GMC Sonoma. However, it is still accessible from the selected car via links, so may be relevant.
Check transfer case fluid at every oil change or every 12 months. Under severe conditions, check more frequently.