Pickup Box Endgate Lock Cylinder Coding

Courtesy of GENERAL MOTORS COMPANY

The pickup box endgate lock uses 6 out of 10 cut positions, 5 through 10 (when counting from the key head). The tumbler positions are staggered from side to side and are not self-retaining. The tumblers MUST be held in place if the key is not fully inserted into the lock cylinder or until the cylinder (4) is assembled into the case (7).

NOTE:

All lock cylinders for side milled keys have right and left tumblers. The location of the tooth of the tumbler determines whether it is right or left. All tumblers are marked 1R, 1L, 2R, 2L, etc. The number is cut depth and the letter identifies right or left. Tumblers identified as 1L to 4L must be inserted in the cylinder side where the first spring pocket is nearest to the back of the key head, tumblers identified as 1R to 4R must be inserted in the opposite side.

1. Hold the cylinder (4) positioned so the side with the tumbler slot nearest to the cylinder head faces up.
2. Insert one tumbler spring (6) into each of the three tumbler slots on the cylinder (4).
3. The first tumbler (5) to be loaded will be the key cut position number 5 (the fifth number in the key code). Determine the cut depth at this position and install the corresponding tumbler (5) into the tumbler slot nearest the front of the cylinder (4). in the same manner, determine the cut depth and corresponding tumbler (5) and install the 2 remaining tumblers into the tumbler slots located at the key positions 7 & 9.
4. Check the correct loading by holding the tumblers (5) in position and fully inserting the key into cylinder (4). All tumblers should be flush with the outside diameter of the cylinder.
5. Rotate the cylinder (4) so the opposite tumbler slots are facing upward and than remove the key. Keep in mind it will be required to hold down all tumblers before removing the key to keep them from falling out.
6. Insert one tumbler spring (6) into each of the three remaining tumbler slots.
7. The first tumbler (5) to be loaded will correspond to the second key cut position (the second number in the key code). Determine the cut depth at this position and install the corresponding tumbler (5) into the tumbler slot nearest the front of the cylinder (4). In the same manner, determine the cut depth and corresponding tumbler (5) and install the 2 remaining tumblers into the tumbler slots located at the key cut positions 8 and 10.
8. Repeat step 4 to confirm all tumblers are properlyassembled.
9. Lightly lubricate the tumbler surface side of the cylinder (4) using the provided grease.
10. With the key fully inserted into the cylinder (4), install the cylinder into case (7), aligning detent recess of cylinder with the inner slot of case. Hold case while pressing in on the cylinder and rotate 90 degrees clockwise and remove the key.
11. Insert the 2 provided shutter springs (3). Insert the shutter (2) in direction until you feel and hear the snap in the 2 shutter legs into the cylinder (4)..
12. Insert cap (1) in direction until you feel and hear the snap into the cylinder (4)..
13. If vehicle is equipped with electronic endgate, install torsion spring (8) in direction as shown.
14. Locate and position lever (9) into tail end of cylinder (4).
15. Finally locate retainer (10) into position to hold the lever and therefore support the whole cylinder (4).
16. As a final inspection, insert the key all the way into cylinder (4) and confirm key freely rotates.