Door Lock Cylinder

The door lock cylinder only uses 7 of the 10 key cut positions, 4-10. The tumbler positions are staggered from side to side, 4 on one side and 3 on the other are self-retaining. The left and right door lock cylinders are identical. The lever assembly determines which side of the vehicle the lock cylinder is for. After removing the current lock, record which lever is used and the orientation of the rod clip.

Fig 1: Door Lock Cylinder Components
Courtesy of GENERAL MOTORS CORP.
1. Rotate the cylinder (1) so the side with the 4 tumbler spring wells faces up.
2. Insert the tumbler springs (2) into the 4 spring wells.
3. Install the tumbler (3) for key cut position 4 in the slot closest to the cylinder head. Install the remaining tumblers, key cut positions 6, 8, and 10, following the key code and same process. Press the tumblers in place until secure.
4. Check the correct loading of the tumblers by inserting the key into cylinder. All tumblers should be flush with the lock cylinder body.
5. Turn the cylinder so the side with the 3 tumblers spring wells faces up.
6. Insert tumbler springs into the 3 spring wells.
7. The first tumbler closest to the front of the lock cylinder to be loaded will be the fifth key cut position. Install the remaining tumblers for the key cut positions 7 and 9. Press the tumbler in place until secure.
8. Check the correct loading of the tumblers by inserting the key into the cylinder. All of the tumblers should be flush with the lock cylinder body.
9. Apply lubricant to the cylinder body and tumbler surfaces along with a small amount in the head of the cylinder using the supplied grease.
10. Install 2 springs (4) into the spring wells in head section of lock cylinder.
11. Snap the shutter assembly (5) into the cylinder.
12. Place the detent spring (6) into the spring well located on the side of the cylinder.
13. Carefully place the detent ball (7) on the detent spring. Depress the detent ball into the cylinder and assemble into the case (8). Detent ball should rest in case slot at the front of the case.
14. Align dimples of the cylinder cap (9) with the 4 recesses in the cap. Secure by pressing the cap into place with light hand pressure.
15. If required, assemble rod clip to lever (10) using the recorded lever information.
16. Assemble lever to lock. Use E-clip (11) to retain lever assembly.
NOTE: The use of the detent ball (7) and ball spring (6) on the door assembly, if provided with the service kit, is optional.
17. Insert the key into the lock and function lock to check for proper assembly and smooth operation.