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 WarningHood Rear Seal Replacement
Hood Rear Seal Replacement
Callout
Component Name
1
Hood Rear Seal
Procedure
Clean the area where the seal will be mounted. Use a suitable solvent
with a mixture of 50?€‰percent isopropyl alcohol and 50?â ...
Control Solenoid Valve and Transmission Control Module Assembly Installation
Control Solenoid Valve and Transmission Control Module Assembly Installation
Callout
Component Name
1
Control Solenoid Valve Assembly Filter Plate
Caution: Use care when removing or installing the filter plate
...
Front Wheel Drive Shaft Seal Replacement - Case Side
Front Wheel Drive Shaft Seal Replacement - Case Side
Callout
Component Name
1
Front Wheel Drive Shaft Oil Seal
Special Tools
DT-23129 Universal Seal Remover
DT-47790 Seal Installer
GE-6125-1B Slide Hamme ...