Impala V8-5.3L (2008)
Ignition Switch Lock Cylinder: Procedures
Key and Lock Cylinder Coding
Special Tools
BO-48370 Lock Cylinder Cap Installer
Ignition Lock Cylinder
The column-mount ignition lock cylinder uses 7 of the 10 key cut positions, 1, 2, and 4 through 8, when counting from the key head. The tumbler
orientations alternate in adjacent locations from side to side with 4 on one side and 3 on the other.
Important: The ignition lock cylinder tumblers (3) are not self-retaining and must be held in place if the key in not fully inserted into the
lock cylinder or until the tumbler retainers (4) are properly staked into the cylinder.
1. Hold the uncoded cylinder assembly (1) positioned so the side with the retention lug is facing upward, spring-loaded retainer facing downward.
2. Insert one tumbler spring (2) each into the 3 tumbler spring holes.
3. The first tumbler to be loaded will be key cut position number 1, the first number in the key code. Determine the cut depth at this position and
install the corresponding tumbler (3) into the tumbler slot nearest the front of the cylinder assembly (1), the end where the key is inserted. It may
be necessary to move the sidebar (5), already pre-assembled into the uncoded cylinder assembly, out slightly to fully install the tumbler into the
correct tumbler slot.
4. In the same manner, determine the cut depth and corresponding tumbler and install the 2 remaining tumblers (3) into the tumbler slots located at
key cut positions 5 and 7.
5. Check for correct loading by holding the tumblers (3) in position and fully inserting the matching key into the cylinder assembly (1). The sidebar
(5) should be flush with the outside diameter of the cylinder assembly.
6. Rotate the cylinder assembly (1) so that the side with the retention lug is facing downward, spring-loaded retainer facing upward, and then remove
the matching key. Remember the tumblers (3) are not self-retaining and must be held in place.
