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:

Vehicle Care
California Proposition 65 WarningRear Axle Bushing Replacement
Special Tools
CH 6616 Hydraulic Hand Pump
CH 6615-10 Hydraulic Cylinder
CH-48377-1 Chisel
CH-49233 Adapter
CH 906-42 Adapter
For equivalent regional tools. Refer to Special Tools
Removal Procedure
Warning: Use of eye goggles is necessary to prevent personal injury.
Remove the re ...
Stationary Window Waterleak Repair
Note: If any water enters the vehicle interior up to the level of
the carpet or higher and soaks the carpet, the sensing and diagnostic
module (SDM) and the SDM harness connector may need to be replaced. The SDM
could be activated when powered, which could
cause deployment of the air bag(s) an ...
Installation Procedure
Position the front end upper tie bar (1) on the vehicle.
Verify the fit of the front end upper tie bar.
Clamp the front end upper tie bar into position.
Weld seam accordingly.
Weld seam accordingly.
Grind down weld seams as needed for related panels and components.
...