72 Cutlass Ignition Switch on a NON-tilt column.
The key switch stopped rotating into the LOCK position a few days ago when floor shift was selected to PARK

Yesterday the switch would not rotate to OFF from the RUN position with the floor shift selector in any position. Jiggling the switch finally released to the OFF position after momentary selecting START with associated momentary bendix teeth grind. Switch still will not rotate to the LOCK position.

I checked the back drive linkage and it appears that nothing has changed. The key switch does not seem to push in or spring outward to allow the switch to rotate to the LOCK position.

I guess I'll have to pull the steering wheel and have look inside the column but I"M SKEERED. Never monkeyed with an in-column switch before.

I'm fresh out of dynamite. Any ideas?

 

You said you checked the backdrive linkage, but have you tried manually rotating the steering column collar behind the key cylinder counter clockwise? Grab it and twist it, then try to remove the key. It doesn’t take much slack in the linkage for the collar to not rotate quite far enough when moving the shifter into Park.

 

Interesting. I've never noticed the collar moving when shifting the floor shifter. I'll take a look and get back to you.

THANKS !!!

 

The collar will not rotate counter clockwise any further than the backdrive rotates it by selecting PARK with the floor shifter. I'll raise the car on the lift and see if I can adjust the backdrive enough to release the key switch.

 

UPDATE: The failed part was the key lock cylinder