Assembling and Coding Door Lock Cylinder

The front side door lock cylinder uses 8 of the 10 cut positions, 4-10. The tumbler orientations alternate in adjacent locations from side to side, with 4 tumblers on each side.

Fig 1: Door Lock Cylinder
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: The front side door lock cylinder tumblers (3) 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 (1) is assembled into the case assembly (4).
1. Hold the uncoded cylinder (1) so that the side with the V-shaped groove for the detent ball (6) is facing upward.
2. Insert 1 tumbler spring (2) into each of the tumbler spring holes.
3. The first tumbler to be loaded will be the key cut position #3, the third number in the key code. Determine the cut depth at this position and insert the corresponding tumbler (3) in the slot nearest the front of the lock cylinder assembly. This is the side where the key would be inserted.
4. In the same manner, determine the cut depth and corresponding tumbler and install the three remaining tumblers (3) into the tumbler slots at key cut positions 5, 7, and 9.
5. Verify the correct loading of the tumblers (3) by holding the tumblers in position and inserting the matching key into the cylinder (1). The tumblers should be flush with the outside diameter of the cylinder.
IMPORTANT: The tumblers (3) are NOT self-retaining and must be held in place.
6. Rotate the cylinder (1) so that the side with the V-shaped groove for the detent ball (6) is facing downward. Remove the matching key.
7. Insert a tumbler spring (2) into each of the 4 tumbler spring holes.
8. The first tumbler to be loaded is key cut position #4. Determine the cut depth at this position and insert the corresponding tumbler (3) in the slot nearest the front of the cylinder (1).
9. In the same manner, determine the cut depth and corresponding tumbler and install the three remaining tumblers (3) into the tumbler slots at key cut positions 6, 8, and 10.
10. Verify the correct loading of the tumblers (3) by holding the tumblers in position and inserting the matching key into the cylinder (1). The tumblers should be flush with the outside diameter of the cylinder.
11. Lightly lubricate the tumbler (3) surfaces using the provided lubrication.
12. Hold the case assembly (4) with the pre-staked detent sprint retainer facing downward.
IMPORTANT: The detent spring and the detent ball are not self-retaining and must be held in place until the coded cylinder is installed into the case assembly (6).
13. Insert one detent spring (5) and one detent ball (6) into the hole located to the rear and inside of the cylinder case assembly.
CAUTION: Wear safety glasses in order to avoid eye damage.
14. With the matching key fully inserted into the coded cylinder install the coded cylinder into the case assembly (4). Hold the detent spring (5) and the detent ball (6) in place until the coded cylinder is fully installed. The ball should line up with the V-shaped groove on the rear of the cylinder, which will prevent the spring and the ball from falling out of the case assembly.
15. Remove the matching key. Keep the coded cylinder (1) fully inserted into the case assembly (4).
16. Insert 1 shutter spring (7) into the shutter spring hole, located on the front face of the cylinder (1).
17. Insert 1 shutter return spring (8) into the shutter spring pocket, located on the front face of the cylinder (1).
18. Install the shutter (9) on top of the shutter return spring (8) and into the recessed grooves in the front face of the cylinder (1). Position the hooked end of the shutter return spring underneath the shutter. Hold the shutter in place against the force of the shutter return spring until you install the cover (10).
19. Install the cover (10) onto the top of the cylinder (1). Snap the legs on the cover onto the cylinder head, and position the ends of the shutter assembly (9) in the grooves located in the front face of the cylinder.
20. Install the lock cylinder cap (11) by aligning the drain hole in the cap with the bottom of the case assembly (4). Snap the cap into place with slight hand pressure. Retain the cap securely on the case assembly. Verify that the shutter spring (7) and the shutter return spring (8) push the shutter (9) and the cover (10) up against the inside surface of the cap.
21. Install the lever (12) onto the end of the cylinder (1).
22. Install the retaining ring (13) in the groove at the end of the cylinder (1) to secure the lever (12) to the cylinder.