WARNING: This page is about a different car, the 2007 Pontiac G5 Pursuit, 2007 Pontiac G5, and 2007 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: View Of Gears
Courtesy of GENERAL MOTORS CORP.
Inspect the gear teeth and the gear splines for excessive wear or damage. Remove minor nicks or scratches with an oil stone. Replace worn or damaged gears.