How to Prevent Your Ignition Key and Steering Lock from Jamming and Leaving You Stranded 

Link to tumbler tool removal and service kits and video instructions: mercedessource... Another great example of the important of preventative maintenance. The ignition tumbler and mechanism inside the steering lock assembly NEVER gets lubricated. Why do you think the keys, tumblers and locks wear out!! When they do your key will not turn - you will be stranded and repairs can cost hundreds of dollars. I feel the reason people do not lube this important part is due to lack of knowledge and the right tools to do the job quickly