Originally Posted by double nickle
I have a 1992 300e and can't get key to turn. I have tried shaing steering wheel with no luck. Any suggestions before I tow
This may happen to all Mercedes's with the mechanical key
. I have 2002 SLK32 which had the same problem. For a while the key could be turned if the steering wheel was wiggled a bit first. THIS IS A WARNING SIGN that soon the ignition lock will fail permanently. It is better to change the steering lock before this happens
. For those of you who are experiencing the key binding, do it now, do not wait until it locks permanently.
I do not think it is usually the key barrel (tumbler) that causes this problem, I think it is the steering lock itself. Steering lock is generic, and it does not have to be made to match with the VIN (=with your key) like the key tumbler needs to be. So the existing tumbler should be reusable. Its condition can be assessed after the steering lock has been disassembled. The steering lock part is usually off the shelf stuff while the tumbler has to be ordered and it may take a week or two probably.
The big issue here is, if the steering lock is permanently locked (i.e. key can not be turned any more), then replacing the lock is VERY difficult. There is a locking pin that holds the steering lock in the steering column, and the pin can be pressed in to release the steering lock only when the key is turned in position 1 or 2 (the idea is to prevent this way the crooks from just disassembling and removing the steering lock if they don't have keys).
So if the steering lock can still be turned but it has those wear symptoms, it should be replaced while it still is reasonably easy job to do. But when the lock is permanently engaged, it is tricky and not all dealerships even know what to do (After some hours on phone trying to reach a technician who would know, without success, I went to dealership to talk to the guys and finally got the advice to try drilling into the center part of the steering lock to access the rod inside; well that advice did not work, either).
The best way to remove the steering lock is to drill or grind the locking pin flat so the the steering lock can be pulled out. That job may take some hours and involves removal of dashboard panels and may involve removal of steering wheel and/or airbag assembly. So if any thieves are reading this, beware: This is so awkward job that do not even try. Go and damage some other car.
The replacement procedure is explained in this link, however, the actual procedure varies from one car to another: MercedesShopWiki: Replacing the Ignition Switch
For the newer cars without mechanical key, I do not know if the steering lock is still the same design so for that I can not give any advice.
Also, do NOT try to turn the key with force (mechanical or not), it will probably just break the key and you have then more trouble. Only thing that may help is to shake the steering wheel vigorously while gently turning the key. But if the steering lock is permanently locked, it is so and now your know what needs to be done.