Ignition key will not turn

[amatheaus]

I have a 1979 300SD.  I got in it one day and the ignition key will not turn.  The steering wheel is not binding.  When I bought the car, they had put in a new ignition cylinder and key.  The key does not look even worn.  There was no warning.  Working perfectly until nothing one day.  I have tried lubing it up and no joy.  Fortunately, this happened in my garage.  I would hate to have to buy a new cylinder and key if this is not it.  Anybody else have any ideas whatsoever?  Thanks in advance.

[TJ 450]

Have you tried rocking the steering wheel while trying to turn the key?

It's hard to imagine that a recent lock would cause a problem due to failure.

Tim

[koan]

Despite what you say about new lock cylinder and key it sounds like the usual worn lock cylinder. Suppose it could be jammed by something associated with the cylinder like the steering lock or the electrical switch but I've never heard of that happening.

If it is a worn lock and it's the first time it's jammed it can usually freed up by persevering with the key, wriggle it side to side, up and down, in and out, and you have to turn it to get it out

koan

[roadsterdude1600]

Did you ever figure out your problem?  Same thing happened to me in my 80 300 SD.  Happened once, and just thought something was in a bind.  wiggled key a while and it worked fine.  Second, third times and "oh well it is just a perskinnity MB"  Finally, any manner of wiggling did not help.  To unscrew the ciylinder you have to have the key in the "1" position.  Impossible if it will not turn.  Finally got it to magically move, and took out the cylinder which seems to work perfectly on the bench.  Now what?  This seems to not be isolated since someone has had it happen before.  How did you fix it?

[hans moleman]

After my cylinder left me stranded and a replacement was unavailable (manufacturer's back order) I removed all the pins from the old one and re-installed it.I gained piece of mind knowing the ignition cylinder will never fail again but lost piece of mind knowing anyone can start the car with a toe-nail clipper .

[roadsterdude1600]

Good solution.  Who would even know to try the toenail clipper?  It looks like a key is required, no?  Also, anyone who has had to work on one of these albatroses would NEVER steal one    Anyway, you can still lock the car.

Do you have a quick primer on pin removal?