Door Lock Cylinder Coding

Fig 1: Lock Cylinder & Cap

Courtesy of GENERAL MOTORS CORP.

Remove the cap from the lock cylinder using a thin bladed screwdriver to carefully pry the cap from the cylinder.

IMPORTANT: When the shutter is removed, the shutter springs may fall out.

Remove the shutter and shutter springs.
Insert the key into the cylinder, turn it a quarter turn clockwise, and remove the cylinder from the housing.
If necessary, remove the pawl from the slot in the housing.

Fig 2: Exploded View Of Lock Cylinder

Courtesy of GENERAL MOTORS CORP.

IMPORTANT: When the tumblers are removed from the lock cylinder tumbler, the springs may fall out.

Push the tumblers out of the lock cylinder using a thin bladed screwdriver.
If necessary, remove the sidebar assembly by pushing it inward while tapping the cylinder, causing it to fall out.

Fig 3: Locating Tumbler Code Stamp

Courtesy of GENERAL MOTORS CORP.

Select the correct tumblers for the desired code by the number stamped on the tumbler.

Fig 4: Exploded View Of Lock Cylinder

Courtesy of GENERAL MOTORS CORP.

IMPORTANT: Make sure the sidebar and tumbler springs are in place before installing the tumblers.

Install the tumblers by applying downward pressure until they lock into position.
To check the coding of the cylinder, insert the key. If the coding is correct, the tumblers and sidebar will be flush with the cylinder with the key inserted.
For assembly, oil the lock set with a light oil or graphite lubricant. Reverse Steps 1-4.