I would like to know how to replace the ignition lock cylinder on my 76 chevy pickup. This is a restoration project which i dont have any key for.
To replace the cylinder, you need to pull the horn button, then unscrew the nut holding the steering wheel on. Once removed, wiggle the steering wheel back and forth (one side to the other) with some force and the wheel should pop off. Make sure to be careful as the steering wheel can pop off unexpectedly and you'll end up smacking yourself in the face. It works best to ensure the wheel is straight before you pull it off, so you know the orientation of how it should go back on.
Once the steering wheel is off, there will be a plastic cover which you can remove fairly easily. When that is off, there is a clocking mechanism which has to come off. If you have strong thumbs, you can press down on this and remove the c-clip which goes around the steering column, which will release this clicking plate. It should look something like this:
Then you'll need to take the white piece out which is the signal return (well, get it out of the steering column, anyway). Then you should see the metal structure underneath. Place a thin bladed screwdriver as shown in this image:
There's a tab which is in the slot there which you're going to press with the screwdriver which will release the ignition cylinder. You should actually be able to stick a screwdriver into the large hole left behind by the now missing cylinder and start the truck very easily. Because of this, you'll not want to leave it like this long ... very easy to get the truck started at this point.
Im assuming you are only trying to replace the ignition because you dont have keys. If so my answer may be an alternative you havent considered.
If the ignition barrel is still intact it may be possible to get a key cut using the factory codes.
On many vehicles the code is stamped into the lock barrel on the drivers door. If you can remove the door lining you may be able to see the code. If so a locksmith should be able to cut you a new key.
I got a set of replacement keys for a Nissan Patrol cut this way for about $25 US.
I dont know if chevy does this, and if so what year they started. But if the door and ignition look original (a matching set) it may be worth a try. Taking a door lock to the lock smith may also help.