Propeller Shaft Description and Operation: Notes
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2007 GMC Yukon XL, 2007 GMC Yukon, 2007 Chevrolet Tahoe, 2007 Chevrolet Suburban, and 2007 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
The propeller shaft is a tube with universal joints at both ends that do not require periodic maintenance. The universal joints transmit power from the transfer case, or from the transmission output shaft, to the differential.