'91 W129 ignition tumbler removal
 

I just purchased a 91 300SL. The ignition tumbler needs replacement. I thought I knew what I was up against, having recently done the job on my 82 300SD. It's much more difficult on this model, and I have run into some dead-ends, both mechanically and searching for a good procedure on the net.

The face of my tumbler has two holes, as if the removal tool would fit, but the corresponding grooves behind the face, normally accessible when the tumbler is in position 1, do not seem to exist.

I have found several references that suggest the tumbler and protective sleeve are a one-time installation on these cars. OK, but there has to be a way to fix the ignition lock when it fails, which it does seem to do on these cars. There's a thread on this forum that refers to a video showing how to remove the old tumbler and sleeve, but the video seems to have disappeared.

How do I get this thing apart? Is it possible to cut a hole in the sleeve with a Dremel or similar, and release a retaining clip of some kind? I have a new tumbler, keyed correctly, in hand. I can see the way to release the latch that holds it in place, if I could only get to it. I am still able, barely, to turn the old tumbler with the old key, so I can turn to position 1, but that doesn't seem to help. The new tumbler has no holes for the release tool, can anyone explain why the old one does?

I would be ecstatic if there was some secret method for releasing the tumbler, without the large-scale dismantling operation I am about to begin. I want to drive my car! That anti-theft stuff is downright pesky. I hope this is the hardest thing to fix on the car...

I have the video which shows the ignition switch removal, but it doesn't show how to change the tumbler. It's 10.5MBts Mpeg1. So, it's too big to post on this forum. I could send to your mailbox if it will accept a file that large.

Anything would help.

I've uploaded the file here....

<a href='http://www.sendspace.com/file/8dx1ej'>http://www.sendspace.com/file/8dx1ej</a>

Let us know if it helps... Someday I may have to do it on my car.

Fixed it!

Once I had the switch and lock assembly out of the car, I tried to drill a hole over the release point for the tumbler. A drill was pretty ineffective against the hardened metal sleeve, and a grinding stone in my Dremel did not last long.

As it turned out, a simple hole over the tumbler release would not have worked anyway. The real problem was the flat metal band holding the sleeve in place. Unless the sleeve was removed, the tumbler was going nowhere.

When the hole drilling failed, I used a metal cutting disc in the Dremel to cut a rectangular hole in the sleeve. Once I cut all the way to the back edge of the sleeve, I was able to pull the metal retainer out and remove it. I mentioned that there were two holes in the face of my tumbler which appeared to be for the removal tool. I think they were there only to fool prospective thieves! There was no groove in the housing, with the exposed tumbler catch release in it. I lined up one of my cuts with the location of that release, using my replacement tumbler as an example, since it was difficult to cut through the housing without also cutting into the housing under it.

In retrospect, I could have cut a 1/2" square hole in the sleeve, with one edge the back of the sleeve. This would have been enough to expose the flat metal retaining band. I could then have finessed the metal band out of its groove, removed the sleeve, cut an access to the tumbler release into the housing, removed the tumbler, and been done.

It's a fact, the tumbler/sleeve/switch housing on these cars is intended to be a one-time use thing. I was successful in reusing everything except my bad tumbler, however, and now I can take it back apart if necessary.

Thanks for the video, without it I would still be stuck, or using the Dremel while everything was still in the car. Judging by the copious amounts of sparks I generated while cutting, this would not have been a great idea.