WARNING: This page is about a different car, the 2007 GMC Yukon XL and 2007 Chevrolet Suburban. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: View Of Manual 2-1 Band Assembly
Courtesy of GENERAL MOTORS CORP.
Install the manual 2-1 band assembly (628) into the transmission case. Inspect for proper alignment with the anchor pin and inspect for freedom of movement.