Steering locks do fail. The inner workings wear and will jam eventually...

I had replaced the tumbler at about 250Kmiles (84 300D) because the keys were extremely worn and wouldn't return to the running position completely after starting. Didn't cure the problem, but got used to it. A few years later I came out of work one day and tried to start my car (at ~310Kmiles). The key wouldn't turn. After wonking around for a few minutes I finally got it to release and the key turned. It seemed that if the wheel was placed in a certain position when locked it would unlock easily. However, a day or two later it took me 30 minutes to get it to unlock and I started leaving the key in it and ordered a new locking assembly. Once installed, it was a beautifully operating mechanism.

The problem is that the key needs to be inserted and turned to position 1 (?) in order to remove the lock. If you can't turn the key then you're in for a long slog getting the mechanism out without damaging anything else down there. The moral is if you suspect that the lock is acting up, replace it as soon as practical. It's a little expensive, but the consequences are much more expensive.

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mjk

'84 300SD 119KMi (Liesl der Diesel)
'84 300D 326KMi when the oil left (former parts car)
'82 300SD 253KMi (new parts car)