For service and parts needs, visit your dealer. You will receive genuine GM parts and GM-trained and supported service people.
Genuine GM parts have one of these marks:

California Proposition 65 WarningSteering Wheel Airbag Coil Replacement
Steering Wheel Airbag Coil Replacement
Callout
Component Name
Preliminary Procedures
Remove the steering wheel. Refer to Steering Wheel Replacement.
Remove the steering column upper trim cover. Refer to Steering Column
...
Rear Disc Brake Pads Replacement
Removal Procedure
Warning: Refer to Brake Dust Warning.
Note: Always replace disc brake pads in axle sets.
Inspect the fluid level in the brake master cylinder reservoir.
If the brake fluid level is midway between the maximum-full point and
the minimum allowab ...
Synchronizers Assemble
1st/2nd Gear Synchronizer
iv
Note: When servicing the synchronizers, retain them in the
same order that they are removed. Keep the synchronizer components together
and mark them to identify correct location.
Install the synchronizer inserts (1) into ...