Assembling and Coding Rear Compartment Lid Lock

The rear compartment lock cylinder only uses 7 of the 10 cut positions, 4 through 10. The tumbler positions alternate in adjacent locations from side to side with 4 on one side and 3 on the other.

Fig 1: Assembling Rear Compartment Lid Lock
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: The rear compartment lid lock cylinder tumblers (7) are not self retaining and must be held in place if the key is not fully inserted into the lock cylinder, or until the cylinder (6) is assembled into the case assembly (1).
1. Hold the cylinder (6) so that the side with 4 tumbler spring wells faces up.
2. Insert the tumbler springs (2) into the 4 spring wells.
3. Insert the tumbler (7) for key cut position 3 into the slot nearest to the front of the lock cylinder (6).
4. Install the 3 remaining tumblers, key cut positions 6, 8 and 10, on this side of the lock cylinder.
5. Inspect for correct loading of the tumblers (7) by inserting the key into cylinder (6). All of the tumblers should be flush with the outside diameter of the lock cylinder (6).
6. Turn the cylinder (6) so that the side with 3 tumbler spring wells faces up.
7. Insert the tumbler springs (7) into the 3 spring wells.
8. Install the tumbler (7) for key cut position 5 into the slot nearest to the front of the lock cylinder.
9. Install the 2 remaining tumblers, key cut positions 7 and 9, on this side of the lock cylinder.
10. Inspect for the correct loading of the tumblers (7) by inserting the key into the cylinder (6). All of the tumblers should be flush with the outside diameter of the lock cylinder (6).
11. Lightly lubricate the tumbler (7) surfaces using the provided lubrication.
12. Install the lock cylinder (6) into case assembly (1).
13. Carefully remove the key, keeping the lock cylinder (6) inserted into the case assembly (1).
14. Insert one shutter spring (5) into each hole located on the front of the cylinder (6).
15. Install the shutter assembly (4) into the recessed area in the front of the cylinder (6). Ensure the ends of the pin on the shutter assembly (4) are positioned in the pin cavities located on the front face of the cylinder (6).
16. Install the lock cylinder cap (3) by aligning the 2 notches in the cap with the drain hole located on the bottom of the case assembly (1) and the corresponding feature on the top of the case assembly (1).

    Press the cap into place with light hand pressure.