Instrument Panel Compartment Door Lock Cylinder

WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, 2009 Chevrolet Silverado, and 2009 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: View Of Lock Cylinder Tumblers

Courtesy of GENERAL MOTORS CORP.

The internal lock cylinder only uses 4 of the ten cut positions, 7 through 10. The tumbler positions are on one side and self-retaining.

Rotate the cylinder (1) so the side with tumbler spring wells faces up.
Insert the tumbler springs (2) into the 4 spring wells.
Install the first tumbler (3) for key cut position 7 in the slot nearest to the front of the lock cylinder. Install the remaining tumblers following the key code.
Press the tumblers in place until they are secure.
Check for correct loading of the tumblers by inserting the key into the cylinder. All tumblers should be flush with the lock cylinder body.