This 2001 Chevrolet Silverado came in with the complaint that the ignition key will not turn most of the time. I removed and inspected the lock cylinder and housing assemblies and found the fault with the tumbler assembly. The following are pictures of dis assembly.
Grasp the corner of the dash and pull out. Repeat pulling process across the dash.
Remove the screws from the bottom cover and pull the whole cover towards the seat and remove. Do not pull just on the bottom edge or you will break retainers. Work the whole panel loose top to bottom.
Remove the tilt wheel handle by wiggling and pulling straight out towards driver’s door
Remove screws from steering column cover, separate and remove.
Remove the steel knee bolster from under steering column. There are four nuts, two on each side.
Locate and separate the ignition switch junction block at left side of steering column.
Now go back to the lock cylinder and work the key until you finally get it switched on. Changing the position of the key in and out slightly while wiggling and rocking the switch will usually allow the key to turn on. It may take quite a bit of trying if the lock is in real bad shape. After the key is turned on, rotate it fully to the crank position and depress the retaining pin in the top of the assembly. With the pin pushed in pull the lock cylinder out.
Install new tumbler by inserting in the ignition housing and turn the key off. Reassemble and you are done.
I am going to do another post on how to code the new tumbler kit to your key.
Update July 11, 2011:
Well it was bound to happen, a bull in a china shop had difficulty reinstalling the lock cylinder and has now messed up his steering column. Wants to blame poor information from this site. I cannot stress enough that all of the work performed by me, on this site requires an extreme eye towards detail and a gentle touch. No part of this repair in particular should require any force or coercion of any kind!
Some extra things to keep in mind:
The new ignition switch needs to be indexed into the exact position, as the old switch was in, when it was removed. The ON position.
The key tumbler assembly needs to be checked, to make sure the locking bar drops flat and even towards the center of the tumbler assembly when the key is installed. If it does not, DO NOT INSTALL IT!
There is a retaining bar/panel that holds the springs in place for the individual tumblers. If it is not fully installed and flat, no protrusions past the outside edge of the tumbler housing, DO NOT INSTALL IT!