and now.....the rest of the story!
For those who are interested, I am better than half way done! It is disassembled and I am educated on the hard ware. There are a few interesting twists I will share with you that explain why I had a hard time taking it apart. It might help you some day.
There are three basic elements.. the tumbler, the steering lock, and the switch. As most of us already know from reading the posts, the key (tumbler) has to be in the "1" position to start the removal process. A jammed tumbler in the off position means a nasty surgical extraction of the whole steering lock assy with a die grinder. The tumbler engages a cam in the steering lock that retracts the lock pin itself. This cam in turn is keyed to the shaft in the switch. Lastly, the switch has a "tee" protruding out the back side which engages a slot in the wire harness plug. I guess this prevents a thief from just unplugging the wire harness and installing his own switch and driving off. So there four rotating pieces all in a line, end to end (the thigh bone is connected to the knee bone, the knee bone is connected to the shin bone...).
To remove the lock cylinder from the column, the system is still must be in the "1" position (tumbler removed, but system not rotated) and the wire harness has to be disconnected to allow the required rotation of the lock cylinder to pull it out.
It seems the common failure mode is for the cam in the steering lock to shear, which allows the key/tumbler to turn as normal, the cam to retract the steering lock, but then does not turn the ignition switch. Hence, even though my tumbler was in the "1" position, the tee in the wire harness to switch connection was not, and I could not get the plug off, not fully remove the steering lock (can you hear me swearing?). Carefully extracting the cam and then using a screw driver to turn the ignition switch directly allows for a very easy removal of the connector. My replacement switch did not have the tee, which furhter confused me, but I knew something had to be screwed up!
One word of caution, once the cam is removed, the steering lock spring loads to the lock position. If the lock assy is engaged in the steering column, which is almost required to have room to access the harness plug, you run the risk of getting the lock assy stuck in the column unless you can finagle the cam back in etc. Removal of the key buzzer switch allows a pick to be installed to help hold the position of the lock spring in place while the cam is pushed back in. The Maintenance CD warns about moving the lock cylinder to certain positions without hardware attached in that you can get into irreversible trouble, so be careful!
The MB dealer says the cam failure is common in this year car usually around 130,000 miles. The new hardware is beefed up. They also recommend replacing the switch at the same time as well as the tumbler. Switch is $30, steering lock is $80 (not in stock, so I am still sitting in the garage), and I did not get the tumbler price, but it seems I read it was around $60 in one of the old posts. I asked about the vacuum switch and he said don't bother unless it is oily, but I might change it anyway.
Hope the long post does not bore you, too much info is better than none! (andim finnnalee geting uzed to uzin the spll chacker!)
Hope to be running "Hot and Black" soon!