As a newbie, I'll submit my first not as a question but a a fix.

My 83' 300TD starting having problems with getting the ignition key to turn once the steering lock was engaged. Talked to my service guy who said it was "common" and would require 4 hours of diamond drilling (and replacement parts) to repair. $$ The problem got worse and worse with eventually my wife abandoning the car for me to try to coax the key to turn.

I was able to follow the simple Haynes manual instructions for removing the lock barrel from the ignition and bought a replacement for $100. (the only thing the Haynes manual has been good for so far!) Turned out though that the problem was actually in the mechanism that slides to lock the steering wheel. It is easy to see how the mechanism works with the ignition barrel removed using needle nose plyers.

I was able to correct the problem by dabbing some "liquid metal" (a two part metal epoxy or glue) on the face to prevent the steering lock slider from sliding too far. It turns out that these parts wear and cause the steering lock to engage too far not allowing the normal key and turning force to release it.

I figure I saved myself >$500 with a single drop of glue.

ps. still working after 2 months...I'll let you know if that changes.

 

you're a good handyman with patience in doing things.