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 WarningTaillamps, Turn Signal, Stoplamps, and Back-Up Lamps
Sedan Taillamp Shown, Hatchback Taillamp Similar
Back-up Lamp
Turn Signal Lamp
Stop Lamp/Taillamp
Sidemarker Lamp
To replace one of these bulbs:
Open the trunk.
Remove the two screws, which secure the taillamp assembly.
Remove the taillamp assembly by pulling it straight ...
Front Wheel Drive Shaft Seal Replacement - Left Side
Front Wheel Drive Shaft Seal Replacement - Left Side
Callout
Component Name
Preliminary Procedure
Raise and support the vehicle. Refer to Lifting and Jacking the
Vehicle.
Remove the front wheel drive shaft from the transm ...
Drive Range, Fifth Gear Default (Gen 2)
If the transmission encounters an electrical component malfunction, the transmission
will default to Fourth gear. All solenoids will default to their normal state. If
the torque converter clutch is applied, it will release. The transmission will remain
in Drive Range?Fourth Gear Default until ...