The procedures that describe replacing the lock cylinder on 1969 through 1982 Corvette steering columns are very similar between a standard (non-adjustable) columns and the Tilt & Telescoping types. The lock cylinder is the same between the two types of columns.
You will need two special tools: A steering wheel hub puller and a locking plate compressor tool. You can usually beg, borrow, or purchase both tools from most automotive stores. One other important point: Disconnect your battery whenever you work on your steering column.
There is a change in the way that the lock cylinder was retained in the turn signal switch housing that occurred during the 1979 model year. Previous to 1979 the lock cylinder had a spring loaded locking tab that engaged a slot in the turn signal switch housing. During the 1979 model year, steering column security was improved with a housing that utilized a cross-bolt that engaged a notch in the lock cylinder. So if you have a 1979 Vette you will have to disassembly the column in order to determine exactly what type of lock cylinder you require.
You do NOT need a key to remove the lock cylinder from the steering column. You do have to remove the horn cap, horn parts, telescope lock (T&T), the hazard warning knob, and the steering wheel and hub. You then need to remove a plastic retainer (T&T).
If you have a T&T column that has not been disassembled through the many years of its existence, you might just as well purchase a new plastic retainer before you start the tear down process. If the retainer is original it will break into several pieces as you try to remove it. This part is required to be in place to prevent your horn from blowing continuously. It is GM #7808385 and is available through GM dealers and also through other automotive part sources. (The GM dealer price is usually quite a bit higher than the other sources). It is that tan part right in the middle of the following picture.
Compress the locking plate so that you can remove a c-clip retainer (T&T) or a small round wire ring . Remove the locking plate and turn signal cancelling cam.
Remove the turn signal switch lever (1969 through 1976) or remove the crossover arm between the turn signal switch and the dimmer pivot (1977 through 1982). Remove the three turn signal switch screws and pull the switch partially out of the column so that you can reach the floor of the turn signal switch housing. (You may need to disconnect the plastic "harmonica" electrical connector down under the dash from the vehicle wiring harness so that you will have enough slack in the turn signal switch wires to allow the switch to just "hang out" of the column head.)
The lock cylinder is held in place by a metal tab that sticks out of the lock cylinder and fits into a rectangular slot in the housing (1969 through early 1979). You need to reach into the slot with a small screwdriver to push the tab back into the lock cylinder. You should then be able to pull the cylinder right out of the column.
On late 1979 through 1982 columns the lock cylinder was retained by a cross-bolt. You will need reach into the housing and unscrew it from the floor of the turn signal switch housing. You should then be able to pull the lock cylinder right out.
Lock Cylinder Installation
Insert the ignition key into the new lock cylinder. Now, hold the case of the lock cylinder and rotate the ignition key all the way clockwise against the stop. (This would normally be the Start position.) You should be able to retract the plastic key buzzer tab and the metal spring tab should retract easily with slight pressure as well.
There is a keyway in the housing. Align the key on the lock cylinder (not the ignition key but the raised section on the lock cylinder case) with the keyway in the housing and push the cylinder into the housing until it hits the sector. Now rotate the ignition key counterclockwise maintaining a light push on the lock cylinder until the drive section of the cylinder mates with the sector. Push in until the locking tab snaps into the housing and the lock cylinder is secure (1969- early 1979). Reinstall the crossbolt on later columns.
Reassemble the column and you are ready to go.
Very complete instructions (for either the T&T or the standard, non-adjustable columns) are available at:
Click on Jim Shea's Steering Papers
Click on Corvette Steering Papers
Scroll down to either the standard column or the T&T column section
Download Disassembly & Repair Paper #1 and the Disassembly & Repair Pic #1 for the appropriate steering column.